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DEEP SEA ELECTRONICS PLCGuide to Synchronising and Load SharingPART 1 – Usage and configuration of the 55xin synchronisation / load sharing systems.Author: - Anthony MantonDSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 1

Deep Sea Electronics PlcHighfield HouseHunmanbyNorth YorkshireYO14 0PHENGLANDSales Tel: +44 (0) 1723 890099Sales Fax: +44 (0) 1723 893303E-mail: Sales@Deepseaplc.comDeep Sea Electronics Guide to Synchronising and Load Sharing –Issue 5Changes over previous edition (Issue 3): Added 557 information. Created by splitting theprevious guide into two parts (was Issue 3)© 2002-2003 Deep Sea Electronics PlcAll rights reserved. No part of this publication may be reproduced in any material form (includingphotocopying or storing in any medium by electronic means or other) without the written permissionof the copyright holder except in accordance with the provisions of the Copyright, Designs andPatents Act 1988.Applications for the copyright holder’s written permission to reproduce any part of this publicationshould be addressed to Deep Sea Electronics Plc at the address above.Any reference to trademarked product names used within this publication is owned by theirrespective companies.Deep Sea Electronics Plc reserve the right to change the contents of this document without priornotice.1 BIBLIOGRAPHY1. Diesel generator handbook. L.L.J.Mahon. ISBN 0-7506-1147-22. On-Site Power Generation. EGSA Education Committee. ISBN 0-9625949-3-82DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

SectionTABLE OF CONTENTSPage1 BIBLIOGRAPHY .............................................................................................. 22 INTRODUCTION .............................................................................................. 63 STEP BY STEP GUIDE.................................................................................... 63.1 CLARIFICATION OF NOTATION AND TERMINOLOGY USED WITHIN THISPUBLICATION................................................................................................................................74 55X SYNCHRONISING AND LOAD SHARING SOLUTIONS......................... 84.1 SINGLE SET NO BREAK RETURN WITH MAINS (“HARD TRANSFER”).......................84.2 SINGLE SET NO BREAK RETURN WITH MAINS (“SOFT TRANSFER”)........................94.3 BASE LOAD PEAK LOPPING / PEAK SHAVING............................................................104.3.1 SINGLE SET ...............................................................................................................104.4 MULTIPLE SET PRIME POWER.......................................................................................114.5 MULTIPLE SET STANDBY TO MAINS SUPPLY (BREAK RETURN).............................124.6 MULTIPLE SET STANDBY TO MAINS SUPPLY (NO BREAK RETURN) ......................135 GENERATOR USES...................................................................................... 145.1 STANDBY GENERATORS................................................................................................145.1.1 TRANSFER SWITCH..................................................................................................145.1.2 NO BREAK TRANSFER .............................................................................................145.2 CONTINUOUS PARALLEL OPERATION.........................................................................155.3 BASE LOAD PEAK LOPPING WITH 555/557/556 CONTROLLER.................................155.3.1 PEAK LOPPING..........................................................................................................166 MULTIPLE GENERATORS ........................................................................... 176.1 MUTIPLE SET PRIME POWER.........................................................................................176.2 MULTIPLE SETS PROVIDING STANDBY TO THE MAINS SUPPLY.............................186.2.1 LOAD-SWITCHING USING 530 ATS .........................................................................186.3 MULTIPLE SETS (STANDBY) – NO BREAK TRANSFER ..............................................197 LOAD SHARING............................................................................................ 207.1 ACTIVE POWER SHARING ..............................................................................................207.2 REACTIVE POWER SHARING .........................................................................................208 THE NEED FOR SYNCHRONISING.............................................................. 219 METHODS OF ADJUSTING VOLTAGE & FREQUENCY............................. 229.1 REMOTE SPEED / VOLTAGE POTENTIOMETERS........................................................229.2 DC VOLTAGE INPUT ........................................................................................................229.3 RAISE / LOWER PUSH BUTTONS...................................................................................2210 REQUIREMENTS FOR SYNCHRONISATION AND LOAD SHARING ...... 2310.1 GOVERNOR AND GOVERNOR INTERFACE..................................................................2310.1.1 ISOCHRONOUS ACTIVE LOAD SHARING...............................................................2310.1.2 DROOP ACTIVE LOAD SHARING.............................................................................2310.2 GENERATOR AND AVR ...................................................................................................2410.2.1 DROOP REACTIVE LOAD SHARING........................................................................2410.2.2 AUTOMATIC REACTIVE LOAD SHARE....................................................................2410.2.3 AUTOMATIC REACTIVE LOAD CONTROL...............................................................2410.3 55X CONTROLLER ...........................................................................................................2510.3.1 FUNCTION COMPARISON CHART...........................................................................2510.3.2 CONNECTION DETAILS ............................................................................................2610.3.3 AUTOMATIC SYNCHRONISING................................................................................2710.3.4 DROOP LOAD SHARING...........................................................................................2710.3.5 ISOCHRONOUS LOAD SHARING.............................................................................2811 LOAD SWITCHING DEVICES .................................................................... 29DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 3

11.1 CHOOSING A LOAD SWITCHING DEVICE .................................................................... 2911.1.1 CONTACTORS........................................................................................................... 2911.1.2 CHARGED SPRING BREAKERS .............................................................................. 2911.1.3 AIR CIRCUIT BREAKERS (ACBS) ............................................................................ 2911.1.4 MOTOR OPERATED BREAKERS............................................................................. 2912 P120 ANALOGUE GOVERNOR INTERFACE MODULE............................3012.1 SPECIFICATIONS............................................................................................................. 3012.2 CASE DIMENSIONS ......................................................................................................... 3012.3 CONNECTION DETAILS .................................................................................................. 31P120 SELECTOR SWITCH SETTINGS....................................................................................... 3212.3.1 SW1 ............................................................................................................................ 3212.3.2 SW2 ............................................................................................................................ 3212.3.3 SW1 / SW2 SELECTOR SETTINGS.......................................................................... 3212.3.4 LOCATION OF SW1 AND SW2 SELECTORS .......................................................... 33P120 ANALOGUE GOVERNOR INTERFACE PHYSICAL LAYOUT ................................... 3313 P121 ANALOGUE AVR VOLTAGE MODULE ............................................3413.1 SPECIFICATIONS............................................................................................................. 3413.2 CASE DIMENSIONS ......................................................................................................... 3413.3 CONNECTION DETAILS .................................................................................................. 3513.4 P121 SELECTOR SWITCH SETTINGS............................................................................ 3713.4.1 SW1 ............................................................................................................................ 3713.4.2 SW2 ............................................................................................................................ 3713.4.3 SW1 / SW2 SELECTOR SETTINGS.......................................................................... 3713.4.4 LOCATION OF SW1 AND SW2 SELECTORS .......................................................... 38P121 ANALOGUE AVR INTERFACE PHYSICAL LAYOUT................................................. 3814 P122 DIGITAL RESISTANCE MODULE.....................................................3914.1 SPECIFICATIONS............................................................................................................. 3914.2 CASE DIMENSIONS ......................................................................................................... 3914.3 CONNECTION DETAILS .................................................................................................. 4014.4 P122 MODE SELECTOR SETTING.................................................................................. 4015 55X MULTISET COMMUNICATIONS LINK ................................................4115.1 MULTISET COMMUNICATIONS LINK CONNECTION DETAILS................................... 4115.2 MULTISET COMMUNICATION LINK SETTINGS ............................................................ 4215.3 MULTISET COMMUNICATIONS LINK SPECIFICATIONS ............................................. 4315.4 MULTISET COMMUNICATIONS LINK ALARMS ............................................................ 4415.4.1 MSC ID ALARM.......................................................................................................... 4415.4.2 MSC DATA ERROR ................................................................................................... 4415.4.3 MSC FAILURE............................................................................................................ 4416 55X CONTROLLER CONFIGURATION FOR SYNCHRONISING ..............4516.1 CHECK SYNC SETTINGS ................................................................................................ 4516.2 AUTO SYNC SETTINGS................................................................................................... 4717 55X CONTROLLER CONFIGURATION FOR LOAD SHARING.................5017.1 MULTI-SET SETTINGS..................................................................................................... 5017.2 LOAD CONTROL ..............................................................................................................5317.2.1 LOAD CONTROL........................................................................................................ 5317.2.2 KW / KVAR LOAD RAMP ........................................................................................... 5418 ON SITE COMMISSIONING ........................................................................5518.1 DISABLING REMOTE ADJUSTMENT OF THE GOVERNOR / AVR .............................. 5518.1.1 RAISE/LOWER INPUTS............................................................................................. 5518.1.2 P120 ANALOGUE GOVERNOR INTERFACE MODULE .......................................... 5518.1.3 P121 ANALOGUE AVR INTERFACE MODULE ........................................................ 5518.1.4 P122 DIGITAL RESISTANCE MODULE.................................................................... 5518.1.5 ELECTRONIC / MOTORISED POTENTIOMETERS ................................................. 5618.2 SETTING GOVERNOR SPEED AND AVR VOLTAGE .................................................... 5618.3 55X CONTROLLER COMMISSIONING ADJUSTMENTS ............................................... 574DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

18.3.1 MULTISET SETTINGS (NOT APPLICABLE TO MODEL 555, 556 OR 557).............5818.3.2 VIEWING THE 55X SYNCHROSCOPE INSTRUMENT.............................................5918.3.3 SYNCHROSCOPE OPERATION ...............................................................................6018.3.4 FREQUENCY SYNCHRONISER SETUP...................................................................6118.3.5 VOLTAGE MATCHING SETUP ..................................................................................6318.3.6 LOAD SHARE / CONTROL SETUP ...........................................................................6418.3.7 MAKING REACTIVE POWER SHARING ADJUSTMENTS (550 MULTISET WITHNO AVR CONTROL) .................................................................................................................6619 TYPICAL CONNECTIONS.......................................................................... 6719.1 TYPICAL CONNECTIONS FOR A SINGLE 550 LOAD SHARE UNIT. ...........................6719.2 TYPICAL CONNECTIONS FOR TWO 550 LOAD SHARE MODULES IN PARALLEL ..6819.3 TYPICAL CONNECTIONS FOR A 556 .............................................................................6919.4 TYPICAL SINGLE LINE DIAGRAM OF MULTI SET MAINS FAIL ..................................7020 APPENDICES ............................................................................................. 7120.1 530 AS MAINS / GENERATOR BUS TRANSFER SWITCH ............................................71DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 5

2 INTRODUCTIONA general overview of generator uses is given including synchronising. This is only to be treated asa guide to newcomers to this particular subject, and should not be treated as a total learningpackage.Part 2 of this manual details interfacing the 55x controller with many of the most common AVRsand Governors in use on generating sets.3 STEP BY STEP GUIDEThis section details the mains steps that need to be taken in producing your synchronising / loadsharing system. This is intended as a guide only and is not a substitute for in depth knowledge ofthe synchronising and load sharing.• Identify your base application. Applications supported by the DSE 55x controllers are detailedin the section headed ‘55x synchronising and load sharing solutions’.• Identify your governor and AVR interface methods. Details of this are contained in the sectionsheaded ‘Interfacing to governors’ and ‘interfacing to Automatic voltage regulators’.• Design your panel and system wiring. DSE can assist with your specific questions on this butcannot design your panel for you. If you want a panel designing, please contact DSE TechnicalSupport Department who may be able to recommend a third party panel designer / buildercapable of producing a synchronising / load sharing system.• Check / adjust the 55x module’s configuration using P810 for Windows. If it is a MultiSetsystem, ensure that the settings for MultiSet Comms Link are correctly configured and theMultiSet comms cable is of the correct specification.• Commission each set in the system as a single standalone set. Before doing this, ensure thegovernor/AVR interface is disabled as detailed in the section entitled ‘On site commissioning’.• Set up the governor and AVR as detailed in their respective manufacturers handbooks.• Before synchronising sets for the first time, double check that all the Bus wiring is correct andthat the controllers initial settings are suitable. This may include lowering the settings for ‘gain’and ‘stability’ in the synchronising, voltage matching and load control sections. Details of waysto verify these are included in the section entitled ‘55x controller commissioning adjustments’.Should you have any queries arising from this manual please contact our TechnicalDepartment:INTERNATIONAL TEL: +44 (0) 1723 890099INTERNATIONAL FAX: +44 (0) 1723 893303E-mail: support@deepseaplc.comWeb: http://www.deepseaplc.com6DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

3.1 CLARIFICATION OF NOTATION AND TERMINOLOGY USED WITHINTHIS PUBLICATION.©NOTE:CAUTION!WARNING!Highlights an essential element of a procedure to ensurecorrectness.Indicates a procedure or practice which, if not strictly observed,could result in damage or destruction of equipment.Indicates a procedure or practice, which could result in injury topersonnel or loss of life if not followed correctly.DEEP SEA ELECTRONICS PLC own the copyright to this manual,which cannot be copied, reproduced or disclosed to a third partywithout prior written permission.Compliant with BS EN 60950 Low Voltage DirectiveCompliant with BS EN 50081-2 EMC DirectiveCompliant with BS EN 50082-2 EMC DirectiveYear 2000 CompliantTwo crossing wires with no interconnection between the two.Three wires, all connected togetherConnections to the 55x controller’s battery supply negative terminal,usually the earthed battery –ve terminal.A.V.R.GovernorDroopIsochronousSynchroniseParallelDatumNominalMains supplyAutomatic Voltage Regulator. Fitted to the alternator to regulate theoutput of the generator.Engine Speed Governor. Fitted to the engine to electronically controlthe speed of the engine.When load is applied to a generator fitted with a droop governor /AVR, the speed/voltage will drop. This is called droop. It is commonfor a droop set to drop between 3% and 10% in speed / voltage fromno load applied to full load applied.A governor with no speed droop, or where speed droop is disabled isknown as an isochronous governor. The engine speed remainsconstant so long as the load levels are within the set’s capability.To get the supplies identically matched, ready for paralleling.Connect two or more supplies together. These supplies must be insynchronism before this can occur.‘centre’ point of an electronic pot, digital resistance orAVR/Governor.The nominal voltage or frequency of the system i.e. 230V 50Hz. Thisis not necessarily the same as the Datum.(i.e. when droop governors/AVRs are used, the datum will be higherthan the nominal )The AC distributed power supply of a power generation company.Often also called the ‘grid’, or ‘utility’ supply.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 7

4 55X SYNCHRONISING AND LOAD SHARING SOLUTIONSAs the 55x synchronising and load sharing controllers can be used in many varying configurations,this chapter explains how the controllers are utilised and what controller options must be fitted.Where droop governors or AVRs are required, this is also mentioned.A more detailed description on synchronising and load sharing follows this section.4.1 SINGLE SET NO BREAK RETURN WITH MAINS (“HARD TRANSFER”)A single set primarily used to provide backup to the mains supply should it fail. When the mainssupply returns, the generator is synchronised to the mains supply and momentarily closed inparallel with it before opening the generator load switching device. This is often called ‘no breakback synching’. No control over governor/avr is made when in parallel so load ramping is notpossible.Controller :Governor :AVR :Load Shareoptions :Description555 auto sync. (Load share version notnecessary)557DroopInterfacemethodDroopInterfacemethod55x Raise/lower relays,P122 digital resistance• No load share available.55x Raise/lower relays,P122 digital resistanceAs no load sharing capability exists, no controlis made over the reactive / active load share. Inapplications of this type, this is not normally arequirement.However, if load sharing is required during thisshort-term parallel, a load sharing 555 or a 557module can be used. This will provide theadditional function of load ramping (softtransfer) during “mains available” transfers.(see ‘base load peak lopping’ example belowfor details of this)NOTE: - It is recommended that ROCOF (Rate of change of frequency) or vector shiftdetection components are fitted when paralleling a generating set with the mains.Additional equipment of this type is normally specified by the local electricity SupplyCompany to protect against the generator feeding the mains grid in the case of a mainsfailure. However, in applications of this type, where parallel time is kept to a minimum, thisis usually not a requirement.If in doubt, you should refer to your local Electricity Supply Company for advice.8DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

4.2 SINGLE SET NO BREAK RETURN WITH MAINS (“SOFT TRANSFER”)A single set primarily used to provide backup to the mains supply should it fail. When the mainssupply returns, the generator is synchronised to the mains supply and momentarily closed inparallel with it before opening the generator load switching device. This is often called ‘no breakback synching’.Controller :Governor :AVR :Load Shareoptions :1) 555 load controller (to provide single setpeak lopping with mains failure protection).Back sync with mains is possible.2) 557 load controller to provide single setpeak lopping with mains failure protection).Back sync with mains is possible.DroopInterfacemethodDroopInterfacemethod• kW control• kVAr controlP120 analogue governorinterfaceP121 analogue AVRinterfaceThe set will produce a fixed amount of powerand will therefore export power to the mainssupply (utility) if the load falls below theconfigured load control level.DescriptionCAUTION!:- External ROCOF/Vectorshift detection equipment MUST be fitted tothe incoming mains supply to detect loss ofmains when in parallel.This external relay MUST be used toprovide a signal into one of the 555/557’sdigital inputs configured to “Auxiliarymains failure”.This is used to ensure termination of thepower export function upon loss of themains supply during paralleling.NOTE: - It is recommended that ROCOF (Rate of change of frequency) or vector shiftdetection components are fitted when paralleling a generating set with the mains.Additional equipment of this type is normally specified by the local electricity SupplyCompany to protect against the generator feeding the mains grid in the case of a mainsfailure. However, in applications of this type, where parallel time is kept to a minimum, thisis usually not a requirement.If in doubt, you should refer to your local Electricity Supply Company for advice.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 9

4.3 BASE LOAD PEAK LOPPING / PEAK SHAVING4.3.1 SINGLE SETA single set is used for multiple purposes. These can be:• Backup to the mains supply in case of mains failure and ‘no break return’ back to mains.• Supplement to the mains supply to reduce mains supply load and hence reduce supply costs.Controller :Governor :AVR :Load Shareoptions :Either :3) 555 load controller (to provide single setpeak lopping with mains failure protection).Back sync with mains is possible.4) 557 load controller to provide single setpeak lopping with mains failure protection).Back sync with mains is possible.5) 550 load controller to peak lop. Multiple550 controlled engines can be used toincrease the amount of power taken by thesets. Mains failure protection is notintegrally provided and if the mains breakeris opened, active back sync with the mainsis not possible.DroopInterfacemethodDroopInterfacemethod• KW control.P120 analogue governorinterfaceP121 analogue AVRinterface• Var/pf control (P121 interface only)The set will produce a fixed amount of powerand will therefore export power to the mainssupply (utility) if the load falls below theconfigured load control level.DescriptionCAUTION!:- External ROCOF/Vectorshift detection equipment MUST be fitted tothe incoming mains supply to detect loss ofmains when in parallel.This external relay MUST be used toprovide a signal into one of the 555/557’sdigital inputs configured to “Auxiliarymains failure”.This is used to ensure termination of thepower export function upon loss of themains supply during paralleling.10DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

4.5 MULTIPLE SET STANDBY TO MAINS SUPPLY (BREAK RETURN)Two or more sets are used to provide backup to the mains supply. When the mains supply fails,the sets are started, synchronised and paralleled together. The generators bus is then closed tofeed the load, the sets sharing power equally as a percentage of their full load rating. Sets areautomatically started and stopped depending upon load levels allowing economic use of theavailable generators. When the mains supply returns, there will be a break in supply to the loadwhile the transfer takes place.Controller :Governor :AVR :Load Shareoptions :Description550 load sharing controller.DroopInterfacemethodDroopInterfacemethodP120 analogue governorinterfaceP121 analogue AVRinterface• Load share kW.• Load share kVArA DSE 530 controller will monitor the mainssupply and signal the sets to start should thesupply fail.All available sets will start and aftersuccessfully paralleling with each other willsignal their availability to the 530 transferswitch controller. The 530 will then transfer theload to the generator bus.The generators will then share power usingtheir load sharing communications link, setsbeing stopped / started depending upon loaddemands.Upon mains restoration, the 530 controller willchange the load back to the mains supply, theninstruct the generating sets that they are nolonger required.See Appendix 1 for further details of thisapplication.12DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

4.6 MULTIPLE SET STANDBY TO MAINS SUPPLY (NO BREAK RETURN)Two or more sets are used to provide backup to the mains supply. When the mains supply fails,the sets are started, synchronised and paralleled together. The generators bus is then closed tofeed the load, the sets sharing power equally as a percentage of their full load rating. Sets areautomatically started and stopped depending upon load levels allowing economic use of theavailable generators. When the mains supply returns, there will be NO break in supply to the loadwhile a ramped transfer takes place.Controller :Governor :AVR :Load Shareoptions :Description550 load sharing controller.DroopInterfacemethodDroopInterfacemethodP120 analogue governorinterface• Load share kW.• Load share kVArP121 analogue AVRinterfaceA DSE 556 controller is connected to the 550load share models via the Multi SetCommunications (a total of sixteen 550s andone 556 can be connected together).A DSE 556 controller will monitor the mainssupply and signal all available sets to startshould the supply failAll available sets will start and after theminimum number of sets have successfullyparalleled with each other, the 556 will transferthe load to the generator bus.The generators will then share the load usingtheir load sharing communications link, setsbeing stopped / started depending upon loaddemands (if enabled)Upon mains restoration, the 556 controller willsynchronise the generator bus to the mainsand ramp the load back to the mains. The setsare then instructed to cool down and stop.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 13

5.2 CONTINUOUS PARALLEL OPERATIONElectricity supply boards have many tariffsbased upon the customer’s load demand. Insome cases, the tariffs can treble during certaintimes of the year if a specific load level isexceeded.In this example, the customer is charged morefor his electricity in the hours around midday, ashis load level places his power usage into thenext charging tariff.In some cases, it can be more cost effective for the customer to provide an alternative powersupply during this time of high tariff. There are a number of possibilities open to him:IllustrationGENSET SUPPLY.DescriptionDuring the time of high load level a single(or multiple) generator(s) could be started,then used to power the load using a ‘nobreak’ transfer. This genset supply must becapable of supplying the entire load duringthis time of high usage.5.3 BASE LOAD PEAK LOPPING WITH555/557/556 CONTROLLERIn this example, a 555, 557 or 556controller is being used in a base loadpeak lopping system. The controller hasbeen configured to start the generating setat 10am, synchronise with the mains andparallel the supplies. It will then export afixed amount of power (kW) to the load andmaintain a specified power factor (bothconfigured using P810 for Windowssoftware).Another alternative for automaticallystarting the set is to utilise an external loadmonitor relay. This would monitor thepower being taken by the load, and when apre-set level is reached, would give the“remote start on load” signal to the555/557/556 controller. The set would beautomatically started, synchronised andparalleled with the mains supply, utilisingload-sharing equipment to minimise usageof the mains supply.When load levels drop, the set would beautomatically stopped.The set can also act as standby to themains providing the set is rated to providethe full site load, or external switching-outof non-essential loads is performed shouldthe mains supply fail. Detection of mainssupply failure while in parallel with thegenerating set must be performedexternally using either ROCOF (Rate OfChange Of Frequency) or Vector shiftdetection relays.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 15

IllustrationDescription5.3.1 PEAK LOPPING. A more advanced variation of the peaklopping system described above is to use a556 or an RS485 enabled 555 load controlmodule with an external device (such as aPLC and a kW transducer), variable PeakLopping can be achieved.The 556 or the PLC will monitor the siteload levels and vary the generators powerproduction. This can be used to ensure theset is used at it’s most economic load level,and prevents the system exporting power.NOTE: - It is recommended that ROCOF (Rate of change of frequency) or vector shiftdetection components are fitted when paralleling a generating set with the mains.Additional equipment of this type is normally specified by the local electricity SupplyCompany to protect against the generator feeding the mains grid in the case of a mainsfailure. If in doubt, you should refer to your local Electricity Supply Company for advice.16DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

6 MULTIPLE GENERATORSThere are many reasons for requiring more than one generator on the same site.The most commons reasons are described below:Illustration6.1 MUTIPLE SET PRIMEPOWERDescriptionIn this example, the site has four generating sets, used asthe primary power source.One genset will be running all the time, to provide power tothe site. If the load demand of the site increases, one ormore generators will be automatically called to start. Theywill then synchronise onto the bus, and provide power inparallel with the other set(s). At this point, the setsconnected to the bus will share the load, normally utilisingload sharing equipment.Using multiple generating sets rather than one large setallows for maintenance to be performed on one of the setswhile the other set(s) are still available for duty.Additionally, if load demands are low, individual generatorscan be started as required, rather than one large generatorbeing used at (for instance) only 25% of its full load rating.If the overall size of the load increases, for instance due tofactory expansion another set can be added to increasecapacity with minimal disruption to the rest of the system.Using this system, “redundancy” can be built in by utilisinga larger number of gensets than is required to supply theload. This way, the load can still be supplied if one or moresets are unavailable due to engine failure or maintenance.The 550 controllers have “no master” ensuring a seamlesstransition when one or more sets are removed from thesystem.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 17

IllustrationDescription6.2 MULTIPLE SETSIf multiple gensets in parallel are used to backup the mainsPROVIDING STANDBY supply, care should be taken when designing the system.In the example above for instance, should the mains supplyTO THE MAINSfail, two possibilities exist. Firstly, if only two generatingSUPPLYsets are providing power to the bus, they must be capableof supplying the currently active load. Secondly, if none ofthe sets are available, they will all start up simultaneously.The first set will close onto the dead bus, and supply powerto the load. Again, the set must be capable of supplyingthis power to the currently active load.Two solutions exist :a) Ensure each generating set is capable of supplying theentire load so that the above situations will not occur.b) Ensure before closing the load switch and poweringthe load with the generating sets, that all of thegenerating sets are available and synchronised ontothe generator bus. While running in this manner, not inparallel with the mains supply, this is called ‘islandedmode’.6.2.1 LOAD-SWITCHING USING 530 ATSThe DSE 530 automatic transfer switch can be used to monitor the mains supply to ensure it iswithin limits. Should the mains supply fail, the 530 can be used to ‘remote start on load demand’the 550 controllers used in the example shown. All sets in the system will start together. The firstavailable set will close onto the dead bus, also closing it’s load switch auxiliary contact. The othergenerating sets will synchronise onto the generator bus, and then close in parallel with it.Connect all of the generating set load switch auxiliary contacts in series and connecting into theauxiliary generator ready input (terminal 10) of the DSE 530 automatic transfer switch inconjunction with further external relay logic to latch this signal. (Further details of this can be foundin Appendix 1 of this publication).The DSE 530 module will sense the generator bus voltage and frequency, and once within limitswill ‘wait’ for the presence of the auxiliary generator ready input. This signifies the correct closure ofall sets in the system onto the generator bus. The mains – generator load transfer is thenperformed by the 530 automatic transfer switch controller.18DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

Illustration6.3 MULTIPLE SETS (STANDBY)– NO BREAK TRANSFERDescriptionIn the example above, it was not possible to performno break transfers to/from the mains supply.If a 556 ‘mains controller’ is fitted, to monitor themains supply and power supplied by the mains tothe load, additional possibilities exist, the mostimportant of which are :1) Should the mains supply fail, 556 can call for thegenerating sets, which will synchronise andclose onto the generator bus. When the sets areavailable on the generator bus 556 can close thegenerator bus interconnecting load switch. Whenthe mains supply returns, the generator bus canbe synchronised and closed in parallel with it, toallow a no break return to the mains supply.2) As the power being supplied by the mains is alsobeing monitored, the 556 can pass thisinformation to the generator controllers, allowingload sharing between the generator bus and themains supply.3) No-break on load testing is possible, by callingfor generators to start. The first to becomeavailable will close onto the dead generator bus,the remaining generators synchronising with thenow live generator bus and closing in parallelwith it. The 556 will then communicate with thegenerating set controllers to effect synchronismof the generator bus with the mains supply.When synchronism has been achieved, the 556can close the supplies in parallel.NOTE: - It is recommended that ROCOF (Rate of change of frequency) or vector shiftdetection components are fitted when paralleling a generating set with the mains.Additional equipment of this type is normally specified by the local electricity SupplyCompany to protect against the generator feeding the mains grid in the case of a mainsfailure. If in doubt, you should refer to your local Electricity Supply Company for advice.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 19

7 LOAD SHARING7.1 ACTIVE POWER SHARINGWe have discussed the synchronising of one or more supplies to the mains or bus supply. Oncethese supplies are closed in parallel with each other, the power will be shared between thesupplies depending upon the generating set characteristics.Consider firstly, two generators operating in droop, closed together in parallel. Providing that thegovernors are set correctly, the ratios of the power supplied to the load by each generator will beproportional to the ratio of governor droop in each system.For instance for a load of 100kW, and two generators with 3% speed droop, the generators willequally share the load, each one supplying 50kW.Consider now one generator operating in droop, connected in parallel with the mains supply, withthe governor adjusted so that the mains and the generator are sharing the load between them.“Backing off” the governor, decreasing the engine’s fuel supply, will result in the mains ‘motoring’the alternator. The generator is being “reverse powered”, absorbing power from the mains supplyand not supplying any power to the load.Instructing the governor to increase fuel to the engine will also have no effect on engine speedbecause the generator is “tied” to the mains. Instead, the generator will begin to supply power tothe load. Further increasing the fuel supply increases the amount of power supplied by thegenerator. This in turn decreases the amount of power supplied by the mains. This is known asKilowatt (kW) export.This can be taken a step further, by paralleling multiple generating sets, all operating isochronously(zero droop). Utilising an active load-sharing controller, precise changes can be made to theamount of power supplied to the load by each generating set. This is achieved by altering theamount of fuel supplied to the engine, and monitoring the amount of power supplied by the set.Each controller can communicate with the others, passing information regarding load levels. Thiscan also be used to bring in or drop off other generating sets as load demands change.7.2 REACTIVE POWER SHARINGAgain, consider two identical generating sets closed together in parallel. Each generator has a‘droop kit’ fitted to the AVR and the field current of each generator is the same. In this situation,they will both supply equal reactive power (kVAr) to the load.Adjusting the amount of field excitation in one of the generators has the effect of that generatorsupplying more or less of the reactive power to the load, matched by an equal drop in the reactivepower supplied by the other generator.Uses of reactive power control include:1) Where multiple generators are used in parallel with each other, the AVRs droop kits will ensurethat the reactive power is equalised between the sets, removing circulating currents caused byimbalance in the reactive power (VAr) supplied by the paralleled generating sets. Thiscirculating current generates heat in the alternator windings, which has the effect of limitingactive power (kW) output, reducing the efficiency of the generating set. If left unchecked,excess circulating current can also damage the alternator windings.2) Power factor control or VAr control. This feature maintains a specific power factor where onegenerating set is used in parallel with the mains supply. This is normally used so that thegenerator maintains its VArs to keep its output at the site load’s average power factor level, tominimise demands on the mains supply.20DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

8 THE NEED FOR SYNCHRONISINGBefore two or more A.C. supplies can be ‘closed’ together in parallel, the frequency, voltage andphase of the supplies must be matched as closely together as possible. Collectively, frequency andvoltage matching are known as synchronisation, although voltage matching may not be required inall applications.Additionally, the phase rotation of the supplies must be the same, i.e. L1, L2, L3 (Anticlockwiserotation) or L3, L2, L1 (Clockwise rotation). The 55x synchronising and load sharing modules willcheck the phase rotation. If this is wrong, the controller can not act, apart from notifying theoperator with an alarm condition. The fault must be corrected before synchronising of the suppliescan be attempted.Synchronisation is achieved firstly by adjusting theengine speed and generator voltage to get thefrequency and voltage of the generator closelymatched to that of the bus / mains supply.Then the phase angle of the supplies is monitoreduntil it is within an acceptable ‘window’ before thesupplies can be closed together in parallel.In the example to the left, the two supplies (shownby the two sine waves) have very similar frequencies(seen as the distance between the “peaks” of thewaves). However, they have very different voltages(overall heights of the waves) and the supplies arenot in phase (the two supply waves are not “on top”of each other).Typically, a frequency difference (called slip frequency) of 0.2Hz, a voltage difference of 5% and aphase angle of 5° will allow for satisfactory paralleling of the supplies.Once the supplies are closed in parallel, the phase of the supplies will not alter, they are ‘locked’ inparallel together.WARNING! Attempting to close the supplies in parallel when they are not insynchronism can result in damage to the generating set system.For example: If synchronising (using two gensets) is effected 120° out of phase, thecoupling torque can be as high as 12 times full load torque, depending on the ratio ofengine and generator inertias (Source: Diesel Generator Handbook L.L.J. Mahon).The actual synchronising process can be achieved through various methods. Put simply, eachmethod involves manipulating the engine governor to increase/decrease engine speed (which hasa direct relationship with generator frequency) and the Automatic Voltage Regulator (whichcontrols the alternator excitation field to produce voltage).The engine governor determines engine speed, by sensing the speed of rotation of the flywheel(normally using a magnetic pickup probe). The governor can then control the actuator to adjust theamount of fuel into the engine, which changes engine speed (similar to the accelerator in a car).Most governors are also fitted with a ‘remote speed adjust’ input to allow an external device toincrease or decrease the set speed of the engine.The Automatic Voltage Regulator effects change in the generator output voltage by controlling thealternator’s exciter field. The AVR adjusts the voltage output to the required set voltage. MostAVRs are also fitted with a ‘remote volts adjust’ input to allow an external device to increase ordecrease the set voltage of the alternator.Automatic synchronisers act upon the ‘remote speed adjust’ and ‘remote volts adjust’ inputs of thegovernor and AVR to affect synchronism and voltage matching.The method of interface between the automatic synchroniser and the governor/AVR depends uponthe type of governor and AVR being used, and are described in the section entitled “Methods ofAdjusting Voltage and Frequency”.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 21

9 METHODS OF ADJUSTING VOLTAGE & FREQUENCY9.1 REMOTE SPEED / VOLTAGE POTENTIOMETERSThe most common way to remotely adjust engine speed/generator voltage is by speed/voltagepotentiometers. These are fitted to the control panel to allow the operator to adjust the supply tothe parameters required and connect directly to most AVRs/Governors, which are fitted withterminals designed for the purpose.A simple way to replace this manual operation with an automatic one is by utilising a motor drivenpotentiometer, which is adjusted automatically by the synchronising controller.Two popular methods of interfacing with potentiometers have been adopted by AVR/Governormanufacturers and are commonly shown on their ‘connection diagrams’ as shown in the followingexamples:IllustrationDescriptionVariable resistanceThis diagram shows a two terminal connection to thegovernor/AVR. The value of the variable resistor(rheostat) depends upon the requirements of thegovernor/AVR being used.This type of interface is suitable for connection to theDSE P122 Digital resistance module. (see sectionentitled P122 digital resistance module)PotentiometerThis diagram shows a three terminal arrangement, forconnection to a potentiometer. The value of thepotentiometer depends upon the requirements of thegovernor/AVR being used.As this method takes a reference voltage and feeds aproportion of this into the ‘input’, this type of interfaceis suitable for connection to the DSE P120 / P121Analogue governor/AVR interface. (see sectionentitled P120/P121 analogue voltage module)9.2 DC VOLTAGE INPUTAnother analogue interface often used by governor manufacturers utilises a DC voltage, the levelof which is proportional to the engine speed required. An example of this is the G.A.C.ESD5500Ethat accepts a DC signal from 2V to 8V to represent adjustment away from the set speed point.When the DC level is at 5V, the engine speed is the governors’ set speed.This type of interface is suitable for connection to the DSE P120 Analogue governor interface. (Seesection entitled P120/P121 analogue voltage module).9.3 RAISE / LOWER PUSH BUTTONSPush buttons to raise/lower the engine speed / alternator output voltage can also be used. Thepush buttons are fitted to the control panel and allow step changes in voltage / frequency with asingle press of the button.IllustrationRAISE / LOWER PUSH BUTTONSDescriptionThis diagram shows switched inputs to thegovernor/AVR to raise/lower speed/voltage.This type of interface is suitable for direct connectionto the 55x controller, though it is usual to fitinterposing slave relays between the controller andthe governor/AVR to provide isolation between thedevices.22DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

10 REQUIREMENTS FOR SYNCHRONISATION AND LOADSHARING10.1 GOVERNOR AND GOVERNOR INTERFACE10.1.1 ISOCHRONOUS ACTIVE LOAD SHARINGFor synchronising purposes where active load sharing is employed, isochronous governors withsync/load share DC analogue inputs should be used.Isochronous active load sharing demands a fast response to variations in the measuredparameters. For this reason, we recommend the use of the P120 analogue governor interfacemodule in applications of this type.Isochronous active load sharing is typically employed in mains peak lopping or multiple set primepower applications.10.1.2 DROOP ACTIVE LOAD SHARINGDroop active load sharing is typically used in no-break changeover systems, where control of theactive load (kW) share is not made during the parallel time.A droop governor must be fitted, with a small amount of droop configured (typically 3% to 5%).Droop provides for a small lowering of engine speed, as the load on the set is increased.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 23

10.2 GENERATOR AND AVR10.2.1 DROOP REACTIVE LOAD SHARINGDroop reactive load sharing is typically used in MultiSet prime power applications to removecirculating currents between the sets.Voltage matching is not always required so long as the AVRs are correctly set to closely match thevoltages between the different sets in the system. Reactive circulating currents are removed by theaddition of the AVR “Droop kit”, and no control is made over the reactive power by the load sharingcontroller.Where voltage matching is required, the generator must be fitted with a remotely adjustable AVR(automatic voltage regulator).When utilising the 55x load sharing controller to perform power factor control or reactive loadcontrol, the AVR must be fitted with Quadrature Droop Compensation (QDC).NOTE: - Quadrature Droop Compensation (QDC or ‘Quad Droop’ for short) is alsosometimes referred to as Quadrature Current Compensation (QCC)10.2.2 AUTOMATIC REACTIVE LOAD SHAREAutomatic reactive load control is used in multiset load sharing applications to minimise thecirculating currents between sets. AVR droop kits go some way to providing this function but theaddition of automatic control provided by the 550 can reduce the circulating current even further.The generator must be fitted with a remotely adjustable AVR (automatic voltage regulator).The 55x Load sharing controller can take full control over the reactive power supplied by thegenerating set.WARNING: - Care should be taken with respect to the grounding methodology of thegenerator neutrals, particularly where alternators with differing winding pitches are to beparalleled.10.2.3 AUTOMATIC REACTIVE LOAD CONTROLAutomatic reactive load control is typically used in peak lopping / peak shaving applications tominimise the kVAr demands on the mains supply.For voltage matching with the mains/utility supply, the generator must be fitted with a remotelyadjustable AVR (automatic voltage regulator).The 55x Load sharing controller can take full control over the reactive power supplied by thegenerating set. This can be used for exporting a fixed amount of power (VAr control)WARNING: - Care should be taken with respect to the grounding methodology of thegenerator neutrals, particularly where alternators with differing winding pitches are to beparalleled.24DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

10.3 55X CONTROLLER10.3.1 FUNCTION COMPARISON CHARTFor supply synchronising and paralleling purposes the 55x controller is available in a number ofdifferent versions. The relative features of each version are detailed below:PowermeasurementinstrumentationAuto550/555non syncOnly ‘enhanced’(powermeasurement)controllers.555 autosync550 loadshare555 loadcontrol557 loadcontrol556 mainscontroller synchronising Isochronous loadsharing / control MultiSetcommunications Automatic first seton the bus N/A N/A determinationAuto start/stop onchanging loaddemands N/A N/A N/A Adjustable runpriority N/A N/A N/A Reverse power Only ‘enhanced’(powermeasurement)controllers.Dead bus relay Earth faultprotectionOnly ‘enhanced’(powermeasurement)controllers.RS232 optionavailable? RS485 optionavailable? ConfigurableLEDs? NOTE: - The 556 mains controller is can only be used with between 1 and 16 550 loadshare modules. It is not a stand alone devise.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 25

10.3.2 CONNECTION DETAILSDetails of connections to the 55x controller are contained within the 55x operators manual and theLink500Plus Communications software manual. However, the following diagram is included toclarify positions of the connectors for synchronising and load sharing applications.Modem serial connector(RS232 version only)Connector AConnector D (Not fitted to550 non-sync/non load sharemodules)Modem power/reset (RS232only) or RS485 connector(RS485 version only)MultiSet CommunicationsLink (load sharing versions only)P810 interface socketDigital expansion for:P122 digital resistance157 relay expansion545/548 LED expansionP120/P121 analoguegovernor/AVR connector(load sharing versions only)Connector BConnector CNOTE: - Details of connections to the MultiSet Communications Link and theP120/P121 connector are detailed within this publication. See sections headed MultiSetCommunications Link, Interfacing to governors and Interfacing to AVRs.NOTE: - All Load Sharing versions of the 550/555 controller are fitted with either anRS232 or an RS485 communications PCB (specified on ordering). For details ofconnections or applications utilising the RS232 or RS485 connectors, please see theLink500Plus software manual.NOTE:- The 557 controller does NOT have the option of either RS232 or RS485communications. For remote communications applications you must use the 550 or 555controller with the appropriate comms option fited.26DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

10.3.3 AUTOMATIC SYNCHRONISINGAutomatic synchronising is the control over engine speed and generator output volts prior to theactual paralleling of the supplies. All ‘auto-sync’ and ‘load-share’ versions of the 55x controller canperform this function, although some governors/AVRs will require an external interface device (Seesections entitled P120/P121 analogue voltage module and P122 Digital resistance module).10.3.4 DROOP LOAD SHARINGDroop load sharing is synchronising and closing the generator supplies in parallel. Then, utilisingthe relative droops of the systems to share power proportional to their droop ratios. No externalcontrol is made over the power share, and hence it is not necessary to use the load-sharingversion of the 55x controller. The auto-synchronising version of the controller can be used tocontrol the governor and AVR to effect synchronism and close the supplies in parallel.Multi-set droop load sharingUsing the auto synchronising 550 controller, it is possible to parallel multiple sets, and share theload equally between them. No other control over the load sharing is necessary as this is takencare of by the droop in the systems.However, unless the governors are identically matched and set, the load share will not be equal. Avery small difference in governor characteristics will lead to a large difference in load shares.Additionally as load levels increase though, the generators output frequency will lower due to thegovernor droop. If these issues cannot be accepted, they can be eradicated by the use of the 550load-sharing controller.NOTE: - Multiple identically rated sets running in parallel must have identical droopsettings on their governors/AVRs to ensure equal load sharing between the generators.Non identical droop settings will result in sharing of the load proportional to the droopratios of the sets.Single set – mains supply droop load sharingThe auto synchronising 555 controller (again without the load sharing option) can be used in “nobreak return” duty with the mains supply. The supplies are only closed in parallel for a very shorttime. The amount of power being supplied by the generator at this time is dependent upon thegovernor setting. The 55x module has no control over the power sharing, but in this application, itis not normally a requirement.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 27

10.3.5 ISOCHRONOUS LOAD SHARINGIsochronous load sharing is the use of isochronous (zero droop) governors, with full automaticcontrol over load sharing (i.e. the amount of power supplied by each set). When either off load, oron load, the generators output frequency will remain the same (i.e. 50Hz).The modules (when used in a MultiSet system) communicate to establish total system load. Thisdata is then used (when the controllers are suitably configured) to decide whether it is necessary tocall more sets for duty as the load levels increase. Additionally sets are automatically unloaded andremoved from the bus if the load level falls low enough to allow this. This allows the generatingsets to be used at a more economical level by ensuring the available (gensets currently running)capacity is close to the actual demand. This reduces the amount of unloaded engines that arerunning, hence improving efficiency and lowering fuel costs.For isochronous load sharing, the governor must be controlled by the P120 analogue governorinterface module.NOTE: - It is recommended that ROCOF (Rate of change of frequency) or vector shiftdetection components are fitted when paralleling a generating set with the mains.Additional equipment of this type is normally specified by the local electricity SupplyCompany to protect against the generator feeding the mains grid in the case of a mainsfailure. If in doubt, you should refer to your local Electricity Supply Company for advice.28DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

11 LOAD SWITCHING DEVICESThe paralleling of two or more supplies requires that the switching of the supplies be performed asclose to zero phase as possible. The check sync feature of the 55x synchronising and load sharingcontroller can accurately measure the phase, and when within the ‘check sync’ window can issuethe load switching closure signal within a few milliseconds. However, there will be a delay in theactual operation and physical movement of the switching device that must be minimised and takeninto account when designing and commissioning any paralleling system.11.1 CHOOSING A LOAD SWITCHING DEVICEIt is typically considered that load switching for parallel supplies be performed within 5 cycles of theclose signal being given to ensure the phase or the supplies has not changed too greatly after theclosing signal has been given.Cycle time Max load switchclosing time50Hz system 20.0 ms 100 ms60Hz system 16.7 ms 83 msTo assist the 55x sync check feature, the load switch closing time can be entered into the “syncadvance” time parameter that can be found on the Edit config’ | Generator | Synchronising | CheckSync page of the P810 for Windows configuration software.NOTE: - The closing time of any load switching device slave relays should also betaken into account. For instance, plug in relays typically used in generating set controlpanels have an operation time of 10-20mS.NOTE: - If fitting a mains (utility) ‘Breaker’ with a trip position, it is recommended to fitone equipped with auxiliary contacts to indicate the “tripped” position. This can be fed intoan input configured to “auxiliary mains failure” so that the module is ‘informed’ of mains(utility) supply breaker tripping should this occur. This is particularly important when the555/7 module is operating in parallel with the mains (utility) supply.11.1.1 CONTACTORSContactors normally operate fast enough for paralleling applications but care should be taken tochoose a contactor that the manufacturer specifies be fast enough for use in parallelingapplications. (See above).11.1.2 CHARGED SPRING BREAKERSIn general, charged spring breakers will operate much faster than contactors.Charged spring breakers ‘pre charge’ a large spring device within the breaker, so that whenbreaker operation is required, the spring is ‘released’ which operates the closing action of thedevice.Typically, the spring is charged when the undervolts input is energised, normally when the set isfirst started. Once charged, the breaker is ready for the closing signal.11.1.3 AIR CIRCUIT BREAKERS (ACBS)A.C.B.’s normally operate fast enough for paralleling applications but care should be taken tochoose an A.C.B. that the manufacturer specifies be fast enough for use in paralleling applications.(See above).11.1.4 MOTOR OPERATED BREAKERSSome types of motor operated breakers are not suitable for paralleling operations due to theexcessive amount of time that the breaker takes to motor into position before the closing processcan be completed. Care should be taken to choose a motor operated breaker that themanufacturer specifies be fast enough for use in paralleling applications. (See above).DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 29

12 P120 ANALOGUE GOVERNOR INTERFACE MODULEDescriptionThe P120 analogue governor interface module provides an isolated,adjustable DC voltage level to connect into the control inputs of manygovernors. This replaces the manually operated or motorisedpotentiometers used in many synchronising and load sharingapplications. The module is also suitable for connection to the loadsharing inputs of many popular engine speed governors.The P120 interface is controlled directly by the 55x controller via itsP120/P121 analogue expansion port. This enables the 55x to adjustthe speed of the engine to match the mains / bus and hence get thesupplies into synchronism. The P120 module is especially suited foruse in active power sharing systems.Photograph12.1 SPECIFICATIONSItemValueDC input Voltage range 8V – 35V DC continuous. Reverse polarity protectedMax operating current 75mA at 12V, 45mA at 24V.Output typeOptically isolated DC voltage levelMinimum output load1000ΩOperating temperature range -30°C to +70°CIndicationsCombined DC power on / Link lost LEDFixingTS32 32mm top hat din rail fixing (din rail not supplied)IP protectionIP30Appropriate standards BS EN 60950, BS EN 50081-2, BS EN 50082-212.2 CASE DIMENSIONS30DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

12.3 CONNECTION DETAILSConnection to the controller is made by connecting the data cable supplied with the interfacemodule to the P120/P121 analogue expansion socket of 55x load sharing enabled controllers.Where more than one analogue expansion module is required in the system, the modules can be‘daisy-chained’ by connecting the “To further expansion” socket of one expansion module to the“To controller” socket of another, as shown below. The order of the modules in the ‘daisy chain’ isnot important.55x AVR/governoranalogue expansionport (see note)+ve55x moduleAux1Aux2Aux3Aux4P120 analoguegovernor interfaceATo controllerBTo further expansionP121 analogueAVR interfaceTo controllerABGovernorGeneratorAVR55x expansion portTo further expansionLAC supplyNLNGeneratoroutputTo 81157xxrelay or 81548xxLED expansion(if required)P157 relay expansion /P548 LED expansionTo controllerTo further expansionP157/P548 expansion units areoptional items and are shown as anexample of the connectionsrequired.NOTE: - The P120 analogue expansion port is only fitted to load sharing enabled 55xcontrollers. Where this function is not fitted to the controller, it is not possible to use theP120 interface modules.Where a different method of interface to the governor is used, load sharing will not bepossible.NOTE: - As the P120 module provides a DC voltage level to the governor, it isimportant that the DC supply to the module is the same supply as provided to thegovernor. It is equally important that the DC supply cable length between the governorand the P120 module is kept to an absolute minimum. It is recommended that wherepossible, the P120 module be fitted in close proximity to the governor control unit tofacilitate this requirement.NOTE: - The length of cable between the P120 interface unit and the governor shouldbe kept as short as possible. Foil screened cable is recommended for this purpose toensure integrity of the control signal.NOTE: - The maximum total length of the cable between the module, P120 and P121 is100 meters.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 31

P120 SELECTOR SWITCH SETTINGSTo enable the P120 analogue Governor interface modules to interface with as many different typesof governor as possible, rotary selectors for voltage range and nominal voltage are fitted. Theseallow the user to configure the output of the module to match the input of the governor.12.3.1 SW1The SW1 selector sets the ‘centre’ point of the interface module’s output. For example: if the outputrange required is 1V to 3V, with the ‘centre’ point being at 2V, then the position of the SW1 selectorwould be 4, giving a voltage offset of 2V.12.3.2 SW2The SW2 selector sets the voltage output range of the interface module’s output. For example: ifthe output range required is 1V to 3V, then the position of the SW2 selector would be 1, giving avoltage range of ±1V from the ‘centre’ point of 2V12.3.3 SW1 / SW2 SELECTOR SETTINGS.For reference purposes, the switch positions perform the following functions:SW1 setting ‘centre’ voltage ofP120SW2 setting Voltage range ofP1200 0V 0 ±0.5V1 0.5V 1 ±1.0V2 1.0V 2 ±1.5V3 1.5V 3 ±2.0V4 2.0V 4 ±2.5V5 2.5V 5 ±3.0V6 3.0V 6 ±3.5V7 3.5V 7 ±4.0V8 4.0V 8 ±4.5V9 4.5V 9 ±5.0VTypical wiring diagrams for many of the most popular governors are included within this manual(See sections entitled Interfacing to Governors).Where these diagrams include the P120 interface module, the switch positions required for bothSW1 and SW2 are given.NOTE: - If the governor you are using is not listed within this manual, it may still bepossible to interface to it using the P120 module. Contact your governor manufacturer tocheck if the product has a DC voltage input for connection to a synchroniser / load sharer,and if so, what the ‘voltage range’ and ‘centre voltage’ is. You can then use the tablesabove to determine settings for SW1 and SW2. P120 terminal A is the negative outputterminal and B is the positive output terminal (providing governor output reversed is notselected in the 55x controller’s configuration).If the ‘centre voltage’ and ‘voltage range’ are not available from the governormanufacturer, providing the input is compatible with a DC voltage signal, it still may bepossible to interface to it using the P120 modules. Contact our Technical SupportDepartment for advice.If the governor is not fitted with a DC voltage input for connection to synchroniser/loadshare modules, then a different interface method will be required. See section entitledInterfacing to governors.32DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

12.3.4 LOCATION OF SW1 AND SW2 SELECTORSAccess to the selectors is gained by removing power to the interface module, then removing thetwo screws that are used to secure the transparent cover. The selectors are positioned as shownbelow:P120 ANALOGUE GOVERNOR INTERFACE PHYSICAL LAYOUT‘centre’ voltage (SW1)Voltage range (SW2)Cover securing screwCover securing screwDSE P120 analogue governor interfaceTo Controller Expansion LED Output DC Supply ConnectionsDSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 33

13 P121 ANALOGUE AVR VOLTAGE MODULEDescriptionThe P121 analogue AVR interface modules provide anisolated, adjustable DC voltage level to connect into the controlinputs of many automatic voltage regulators. This replaces themanually operated or motorised potentiometers used in manysynchronising and load sharing applications. The module isalso suitable for connection to the load sharing controllerinputs of many popular AVRs.The P121 interface is controlled directly by the 55x controllervia its AVR analogue expansion port. This enables the 55x toadjust the alternator voltage output to match the mains / busand hence get the supplies into synchronism. The P121module is especially suited for use in reactive power sharingsystems.Photograph13.1 SPECIFICATIONSItemValueAC input Voltage range 152 V AC to 305 V AC (+20%)AC input frequency50Hz to 75Hz at rated engine speedMaximum burden2VAAC input isolationDouble insulated transformerOutput typeOptically isolated DC voltage levelMinimum output load1000ΩOperating temperature range -30°C to +70°CIndicationsCombined AC power on / Link lost LEDFixingTS32 32mm top hat din rail fixing (din rail not supplied)IP protectionIP30Appropriate standards BS EN 60950, BS EN 50081-2, BS EN 50082-213.2 CASE DIMENSIONS34DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

13.3 CONNECTION DETAILSConnection to the controller is made by connecting the data cable supplied with the interfacemodule to the P120/P121 analogue expansion socket of 55x load sharing enabled controllers.Where more than one analogue expansion module is required in the system, the modules can be‘daisy-chained’ by connecting the “To further expansion” socket of one expansion module to the“To controller” socket of another, as shown below. The order of the modules in the ‘daisy chain’ isnot important.55x AVR/governoranalogue expansionport (see note)+ve55x moduleAux1Aux2Aux3Aux4P120 analoguegovernor interfaceATo controllerBTo further expansionP121 analogueAVR interfaceTo controllerABGovernorGeneratorAVR55x expansion portTo further expansionAC supplyGeneratoroutputTo 81157xxrelay or 81548xxLED expansion(if required)P157 relay expansion /P548 LED expansionTo controllerTo further expansionP157/P548 expansion units areoptional items and are shown as anexample of the connectionsrequired.NOTE: - The AVR analogue expansion port is only fitted to load sharing enabled 55xcontrollers. Where this function is not fitted to the controller, it is not possible to use theP121 interface modules.Where a different method of interface to the governor is used, load sharing will not bepossible.NOTE: - The length of cable between the P121 interface unit and the AVR should bekept as short as possible. Foil screened cable is recommended for this purpose to ensureintegrity of the control signal.NOTE: - The maximum total length of the cable between the module, P120 and P121 is100 meters.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 35

13.4 P121 SELECTOR SWITCH SETTINGSTo enable the P121 analogue AVR interface module to interface with as many different types ofAVR as possible, rotary selectors for voltage range and nominal voltage are fitted. These allow theuser to configure the output of the module to match the input of the AVR.13.4.1 SW1The SW1 selector sets the ‘centre’ point of the interface module’s output. For example: if the outputrange required is 1V to 3V, with the ‘centre’ point being at 2V, then the position of the SW1 selectorwould be 4, giving a voltage offset of 2V.13.4.2 SW2The SW2 selector sets the voltage output range of the interface module’s output. For example: ifthe output range required is 1V to 3V, then the position of the SW2 selector would be 1, giving avoltage range of ±1V from the ‘centre’ point of 2V13.4.3 SW1 / SW2 SELECTOR SETTINGS.For reference purposes, the switch positions perform the following functions:SW1 setting ‘centre’ voltage of P121 SW2 setting Voltage range of P1210 0V 0 ±0.5V1 0.5V 1 ±1.0V2 1.0V 2 ±1.5V3 1.5V 3 ±2.0V4 2.0V 4 ±2.5V5 2.5V 5 ±3.0V6 3.0V 6 ±3.5V7 3.5V 7 ±4.0V8 4.0V 8 ±4.5V9 4.5V 9 ±5.0VTypical wiring diagrams for many of the most popular AVRs are included within this manual (Seesection entitled Interfacing to AVRs).Where these diagrams include the P121 interface modules, the switch positions required for bothSW1 and SW2 are given.NOTE: - If the AVR you are using is not listed within this manual, it may still be possibleto interface to it using the P121 modules. Contact your AVR manufacturer to check if theproduct has a DC voltage input for connection to a synchroniser / load sharer, and if so,what the ‘voltage range’ and ‘centre voltage’ is. You can then use the tables above todetermine settings for SW1 and SW2. P121 terminal A is the negative output terminal andB is the positive output terminal (providing governor output reversed is not selected in the55x controller’s configuration).If the ‘centre voltage’ and ‘voltage range’ are not available from the AVR manufacturer,providing the input is compatible with a DC voltage signal, it still may be possible tointerface to it using the P121 modules. Contact our Technical Support Department foradvice.If the AVR is not fitted with a DC voltage input for connection to synchroniser/load sharemodules, then a different interface method will be required. See section entitledInterfacing to AVRs.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 37

13.4.4 LOCATION OF SW1 AND SW2 SELECTORSAccess to the selectors is gained by removing power to the interface module, then removing thetwo screws that are used to secure the transparent cover. The selectors are positioned as shownbelow:P121 ANALOGUE AVR INTERFACE PHYSICAL LAYOUT‘centre’ voltage (SW1)Voltage range (SW2)Cover securing screwCover securing screwDSE P121 analogue AVR interfaceTo Controller Expansion LED Output AC ConnectionsWARNING! Suitable steps should be taken to isolate the generator supply from theP121 AVR interface module before removing the cover. The cover must not be removedwhile the engine is running.Ensure the cover is correctly refitted before reconnecting the power and attempting tostart the engine.38DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

14 P122 DIGITAL RESISTANCE MODULEDescriptionThe P122 digital resistance module is designed to connect tothe remote adjust inputs of many examples of automaticvoltage regulators and governors. The module replaces thetraditional “2 wire” variable resistor (rheostat). It is controlleddirectly by the 55x controller via its expansion output port. Thisenables the 55x to adjust the speed of the engine and voltageof the generator to match the mains / bus and hence get thesupplies into synchronism.Photograph14.1 SPECIFICATIONSItemValueDC input Voltage range8V to 35V DC continuous. Reverse polarity protected.Max operating current250mA at 12V, 125mA at 24VStandby current (output at datum resistance) 35mA at 12V, 23mA at 24VOutput resistance range1KΩ, 5KΩ, 10KΩ, 100kΩ (specify on ordering)Output rating 0.6WOperating temperature range-30°C to +70°CIndicationsDC power on LED. Separate Link Lost LEDFixingTS32 32mm top hat din rail fixing (din rail not supplied)IP protectionIP30Appropriate standards BS EN 60950, BS EN 50081-2, BS EN 50082-214.2 CASE DIMENSIONSDSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 39

15 55X MULTISET COMMUNICATIONS LINKThe 55x load-sharing module is fitted with a data communications link known as the MultiSetCommunications Link (MSC Link). This should only be connected to other DSE controllers asshown below and must not be connected to any other device.The MSC Link is used by the 55x controllers advanced load share functions. Some examples ofthis are:• Determining which set is to be the first to close onto a dead bus, eliminating the need forcomplex external relay logic as traditionally used to perform this function.• Determining the level of the total system load for use in load sharing applications. This is thedigital equivalent of analogue load sharing lines.• Identifying whether the set should start / stop based upon load levels when used in running onload demand mode.15.1 MULTISET COMMUNICATIONS LINK CONNECTION DETAILSNOTE: - The MultiSet Communications link terminals (Mh, Ml & SCR) are only to beconnected to other DSE controllers as shown, and must not be connected to any otherdevice.NOTE: - Do not connect the MSC cable screen (SCR) to earth at any point. Protectionfrom interference is provided within the module and may be compromised by earthing theMSC cable screen.NOTE: - The maximum total length of the MSC link is 250 meters.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 41

15.2 MULTISET COMMUNICATION LINK SETTINGSThe MSC link is a data transmission line, requiring that a 120Ω termination resistor is present atthe ends of the cable on the Mh and Ml lines. On pre version 7 modules, this termination resistor isprovided within the 550 module and is enabled / disabled via a switch, located behind the module’srear fascia plate.To access the switch, remove the six small screws from the rear of the module and gently removethe back plate. The switch is located above the MSC connection socket.However on version 7 and later modules the resistor is supplied loose and must be fitted to the twoends of the cable on the Mh and Ml lines.Switch upSwitch down120Ω termination resistorNo termination resistorMSC Terminator switch (RS232 version)MSC Terminator switch (RS485 version)42DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

NOTE: - Only the “end” modules in the MSC link must have the 120Ω terminationresistor enabled (switch up). All other controllers must have the termination resistorsdisabled (switch down).15.3 MULTISET COMMUNICATIONS LINK SPECIFICATIONSParameterConnection typeCable impedanceMaximum cable resistanceMaximum cable capacitance (between conductors)Maximum cable capacitance (conductor to shield)Termination resistors (one at each end of cable run)Max number of 55x controllers per busMax cable lengthMax Spur length (see note 2 below)Recommended cableValueTwin conductors with screen. Ensure screenis connected to SCR terminal of everycontroller on the bus.120Ω0.050Ω/m75pF/m110pF/m120Ω 4W (switchable)16 (only 3 shown above for clarity)250m1m* BELDEN 9841 120Ω cable.NOTE :- * Deep Sea Electronics part number. 016 030WARNING! 120Ω impedance cable must be used for the MultiSet CommunicationsLink.Use of any other impedance cable may cause intermittent failures in communications,indicated by MSC alarms although the system may function normally during engine / paneltesting.NOTE 1: - The 120Ω terminator must be enabled on the first and last devices on thecommunications bus. See section header MSC Settings for further details.NOTE 2: - It is important that the MultiSet Communications Link cable is run from onemodule to the next in a ‘bus’ fashion. ‘Spurs’ off this bus should be avoided wherepossible, but where a spur is unavoidable; its length should be kept less than 1m from thebus cable.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 43

15.4 MULTISET COMMUNICATIONS LINK ALARMSSeveral alarms are provided to warn the operator of possible problems with the communication linkbetween the gensets.15.4.1 MSC ID ALARMEach genset must have a unique MSC ID so that they can properly communicate. Should two ormore sets have the same ID then one or more of the affected sets will declare “MSC ID ERROR”this will cause an electrical trip on the affected set. The correct ID must be set using the P810software.NOTE: - To avoid possible problems with spare modules it is suggested that units arecommissioned in the system starting with ID 1 and then 2,3… etc. Any modules used asspares should be configured as number 16,15… etc. These can then be added to thesystem without causing any conflicts with existing modules. Alternatively, use the P810for Windows configuration software to reconfigure the module to suit.15.4.2 MSC DATA ERRORWhen the sets are communicating on the MultiSet Communications link, should the data becorrupted the affected modules will display ‘MSC DATA ERROR’. This will cause an electrical tripon the affected set.CAUTION! - Care should be taken to ensure that correct wiring is used between themodules, the MSC terminator is correctly enabled on only end units on the link and thatmaximum cable run distances are not exceeded. Should data error alarms be apparent,operation of the MultiSet system may not be possible.15.4.3 MSC FAILUREIf the number of modules communicating on the Multset communications link should fall, then anMSC failure alarm will occur. This can be configured to a ‘warning’ or ‘electrical trip’ type alarm.Should the number of modules on the communications link fall below the “Minimum modules onMultiset comms link” configurable setting, an additional alarm is triggered. This alarm can bedisabled, or configured to generate a warning or electrical trip alarm.If the number of modules communicating on the Multset communications link should rise, then anyexisting ‘MSC failure’ warning alarm is cleared, and all communicating modules are automaticallyreconfigured to ‘expect’ the increased number of sets on the bus.Additionally, one of the module’s digital inputs can be configured so that the MSC failure alarm isdisabled when the input is active. The module can be configured to alert / remind the user of thisvia an indication or warning alarm if required via the “Multiset comms alarm disabled action”setting.NOTE:- For details on the MSC failure alarm settings, you are referred to the sectionentitled “5xx controller configuration for load sharing” elsewhere in this manual.44DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

16 55X CONTROLLER CONFIGURATION FOR SYNCHRONISINGThe 55x controller must be correctly configured before synchronising can take place. Thisconfiguration is performed using the DSE P810 for Windows software, in conjunction with the P810interface.16.1 CHECK SYNC SETTINGSGenerator Check Sync DescriptionSettingsThis setting is used to configure the synchronising mode:- = The module will not synchronise when operating thegenerator (or mains) contactors. = The module will not operate the generator (or mains)contactors until both supplies (generator and Bus/or mains) aresynchronised.This function will also show or hide the Synchroscope display onthe module LCD.CAUTION! Synchronising must not be disabled in asystem which is not fitted with load-switching deviceinterlocks.This setting is used to set the voltage at which the 55x controller’sdead bus relay will operate. When the bus voltage is above thissetting, the controller will synchronise with the bus before closingits load-switching device.This setting is used to set the maximum frequency the generatoris allowed to be slower than the bus for synchronising to takeplace. Only when the frequency is greater that this setting will themodule try to close the contactors.If the setting is set to 0.0Hz then the generator will only be allowedonto the bus when coming in faster than the bus frequency. Thiscan be used to ensure that the set will take load when closed inparallel with the bus, and will not cause a reverse power alarmgenerated by the bus “driving” the set.This setting is used to set the maximum frequency the generatoris allowed to be faster than the bus for synchronising to takeplace. Only when the frequency difference is less that this settingwill the module try to close the contactors.This setting is used to set the maximum voltage differenceallowed between the generator and the bus/mains supply. Onlywhen the voltage difference is less than this setting will themodule try to close the contactors.This setting is used to set the maximum phase angle differenceallowed between the generator and the bus/mains supply. Onlywhen the phase angle difference is less that this setting will themodule try to close the contactors.This setting is used to determine how much the module will‘forward forecast’ the event of synchronism. The module will usethe advance time to predict when the generator and bus/mainssupply will be synchronised and issue the close command inadvance. This allows the module to ensure that the closingdelays in the contactors or breakers are minimised.This value should be set to the typical closing time of the loadswitchingdevice in use.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 45

Generator Check SyncSettingsFail to sync timeContinuous ParallelingParallel Run TimeDescriptionThis setting is used to determine how long the module willallow for the generator and bus/mains supplies to synchronise.If this timer expires and the generator and bus/mains have notsynchronised then a ‘Fail to Sync’ Warning alarm will beissued.Only available on the 555/7 moduleThis settings is used to configure the paralleling mode:- = The module will only allow both the generator and mainsto be paralleled for the duration of the Parallel run timer. Thismay be used to allow no-break transfers, etc. = The module will allow both the generator and mainssupply to run in parallel continuously. This may be used inpeak lopping or load sharing applications.Only available on the 555/7 moduleThis setting is used to determine how long the module willallow the generator to run in parallel with the mains supplyonce synchronised. This will be used both in transferring tothe generator and when transferring back to the mains.46DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

16.2 AUTO SYNC SETTINGSGenerator AutoSynchronising SettingsInterface OptionsFunctionThese settings are used to configure the auto synchronisingmode of interfacing to the engine governor and AVR.For details of connections and interface options with governorsand AVRs, please refer to the sections headed Interfacing toGovernors and Interfacing to AVRsInternal Relays – No external interface is fitted and the governoror motorised pot is controlled by the 55x modules own internalrelays.NOTE: - It will be necessary to configure two of themodule relays to provide the required ‘Speed raise’ and‘Speed Lower’ signals.P120 Analogue module – This external interface is used toprovide a DC voltage output to interface with many engine speedgovernors remote speed adjust or load sharing controller inputs.For further information regarding this interface, refer to thesection headed “P120 Analogue governor interface module”.P122 Digital Resistance – This external interface is used toprovide an output, which mimics that of a 2-wire rheostat(variable resistor). For further information regarding thisinterface, refer to the section headed “P122 Digital Resistancemodule”.NOTE:- P122 is included for legacy support of theAutoSync (not loadshare) controllers only.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 47

Generator AutoSynchronising SettingsFunctionNone – No external interface is fitted between 55x controller andthe AVR and no control over voltage matching or VAr sharing willbe made.Internal Relays – The AVR or motorised pot is controlled by the55x modules own internal relays.NOTE: - It will be necessary to configure two of themodule relays to provide the required ‘Voltage raise’ and‘Voltage Lower’ signals.P121 Analogue module - This external interface is used toprovide a DC voltage output to interface with many AVRs remotevoltage adjust or load sharing controller inputs.For further information regarding this interface, refer to thesection headed “P121 Analogue AVR interface module”.P122 Digital Resistance – This external interface is used toprovide an output, which mimics that of a 2-wire rheostat(variable resistor). For further information regarding thisinterface, refer to the section headed “P122 Digital Resistancemodule”.NOTE:- P122 is included for legacy support of theAutoSync (no loadshare) controllers only.Only available in conjunction with P120, P121 or P122modulesThis allows the module to interface with a greater diversityof AVRs and governors. = Lower voltage (P120/P121) or lower resistance (P122)equates to lower speed / voltage. = Lower voltage (P120/P121) or lower resistance (P122)equates to higher speed / voltage.48DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

Generator AutoSynchronising SettingsSynchronising reset optionsFunctionIf the set is on the generator bus by itself, with no other setsin parallel with it, then this is the action that the 55xcontroller will take :Disabled – The speed and voltage will remain at current levels.Reset to Datum –The 55x load control module will select the“centre point” of the control of the P120, P121, P122 ormotorised potentiometer). This disables the ‘bias’ of the 550 onthe system volts/frequency, returning them to the levels initiallyset using the governor/AVRs own potentiometer settings.Reset to Nominal (550 load share only) –The 550 load sharingmodule will effect changes to the governor and/or AVR to keepthe system voltage and frequency at nominal levels. Theselevels are user adjustable on the ‘generator’ tab accessible viaP810 for Windows configuration software.This is used to ensure the nominal voltage/frequency of thesystem is maintained even if droop is configured.NOTE: - When multiple 550 controlled sets are inparallel, they will share load equally (based on theirpercentage of full load). In addition, the 550 modules willact together to keep the voltage and frequency at nominallevels. This will occur regardless of the setting of the “onload synchronising reset” option.NOTE: - For details on configuring non-synchronising items within the 55x controlleryou are referred to the P810 for Windows product manual.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 49

17 55X CONTROLLER CONFIGURATION FOR LOAD SHARINGThe 55x controller must be correctly configured before load sharing can take place. Thisconfiguration is performed using the DSE P810 for Windows software, in conjunction with the P810interface.17.1 MULTI-SET SETTINGS(Only available on load sharing versions of the 550 controller, where multiple generators controlledby 550 modules are providing prime power to the load).The Multi-set settings page is used to configure the automatic starting and stopping of generatorsbased upon load level demands.Running on load demand DescriptionThis system is enabled by activating digital inputs on thecontrollers that have been configured to Remote Start onload demand. Every controller in the MultiSet system musthave a digital input configured and connected in this way.This enables generating set(s) to be taken out of servicefor maintenance, while still allowing the remainder of thesystem to operate.Upon activation of the Remote Start on load demand input,all the sets in the system will start up. The first one tobecome available will close onto the dead bus,communicating with the other sets to instruct them tosynchronise onto the now live bus, before closing the loadswitch in parallel with it.If too much generating set capacity is available to supplythe current load, the sets that are not required will begintheir stop delay timers, after which they will drop off the busand stop.Occasionally while one or more sets are already availablein ‘running on load demand’ mode, it may be required tomake all generating capacity in the system available toprovide power to the load. For instance, this may benecessary prior to switching in a large load that thecurrently available generating sets may not be able tosupply. To provide this function, a digital input on eachcontroller in the system must be configured to Remote starton load. Activating this input will cause each controller tostart it’s generating set, synchronise with the bus and closeit’s supply in parallel with it.The sets will continue to provide power until removal of theRemote start on load input, when, providing the Remotestart on load Demand input is present, the system will dropsets off the bus depending upon the total load levels.Details of how to configure these digital input functions arecontained within the P810 for Windows software manual.50DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

Multi-set settingsFunctionMultiset comms failure action : The action that will be takenif one or more modules ‘drop off’ the multiset communicationslink.Warning: An alarm condition will be given, but the sets willstill be able to run and take load.Electrical trip: An alarm condition will be given, the set will beremoved from the bus and shutdown after the cooling timer.Too few modules action : the action that will be taken if thenumber of modules communication on the MSC link is lessthan the “minimum modules on Multiset comms link” setting.None : Too few modules on the MSC link will not generate analarm condition.Warning: An alarm condition will be given, but the sets willstill be able to run and take load.Electrical trip: An alarm condition will be given, the set will beremoved from the bus and shutdown after the cooling timer.Minimum modules on Multiset comms link : The minimumnumber of modules allowed on the MSC link before an alarmis generated. The type of alarm can be configured using “Toofew modules action” detailed above.Multiset comms alarms disabled action : The action thatwill be taken if the Multiset comms alarms are disabled viaconfigurable input or external communications control.None : Disabling the MSC link alarms will not generate analarm condition.Indication : Disabling the MSC link alarms will generate an‘indication’, but no alarm condition is generated.Warning: An alarm condition will be given to remind theuser/operator that the MSC alarms have been disabled.Load level for more sets to run: The load level at which the550 controller decides that additional generating set capacityis required to supply power to the load.Once this load level is exceeded, the next highest priority setin the sequence (determined using the Genset Run Priority)will begin it’s start delay timer. Once this has expired, the setwill run up, synchronise and take load. Should the set fail totake load, it will communicate this using the MultiSetCommunications Link which will signal the next generating setin the sequence to take its place.The starting sequence will be terminated should the load leveldrop below the Load level for more sets to run while the startdelay timer is in progress. This allows for short term increasesin load.NOTE: - It is recommended that each set in thesystem have the same value configured for thisparameter.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 51

Multi-set settingsFunctionLoad level for less sets to run: The load level at which the550 controller decides that the generating set capacity can bereduced by dropping sets off the bus.The system looks at the loading on each generator, anddetermines what the loading would be, should one generatorstop. If this figure is below the Load level for less sets to runsetting, the lowest priority set in the sequence (determinedusing the Genset Run Priority) will begin it’s stop delay timer.Once this has expired, the set will ramp off load and stop.Should the set fail to shed load, it will communicate this usingthe MultiSet Communications Link, and the next lowest set willtake its place.Should the load level rise above this set point during the stopdelay timer, then the timer is cancelled and the set willcontinue to supply power to the load.This allows for short term drops in load, without decreasingsupply capacity, only for it to be increased again a short whilelater.NOTE: - It is recommended that each set in thesystem have the same value configured for thisparameter.52DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

17.2 LOAD CONTROL(Only available on load sharing versions of the 55x controller)Soft transferDescriptionWhen either of the load sharing modes are selected (see below), the 55x controller will perform a‘soft’ load transfer when taking up or shedding load.Upon activation of the load-switching device, the 55x load sharing system controls the generatingset to take up the minimum load. Load is then ramped up to either the set’s share of the load (Loadshare mode) or to the maximum load level (Load level control mode).When a paralleled set is to shed it’s load, first the load is ramped down to the minimum load level,and then the load switch is deactivated, removing the generator from the bus.‘Soft transfers’ of this type have many benefits, the most obvious of which are:• When the generator is removed from the bus, other sets in the system are not suddenly loadedwith the load share that was being supplied by the generator being removed. Instead, the loadis slowly ramped, allowing time for the remaining sets to take up their share of the load.• Opening of the load switch occurs at a much lower load level, helping to reduce arcing of thecontacts.17.2.1 LOAD CONTROLLoad Control settingsFunctionLoad control modeOptions :Disabled: No load sharing will take place.Load Share (550 only): The load will be shared between allthe sets in the system.kW fixed export: The generator will export a fixed amount ofactive (kW) power.NOTE: - kW fixed export is only used in conjunctionwith generating sets in parallel with the mains supply.Generator full load rating: The full load rating (in kW) of theset.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 53

Load Control settingsFunctionReactive load control modeNot available when Active (kW) load share mode is set toDisabled.Options :Disabled: No reactive power (VAr/pf) sharing will take place.VAr Share: Reactive power (VAr) will be shared between allthe sets in the system.VAr fixed export: The generator will produce a fixed amountof reactive power (VAr) for use when in parallel with the mainssupply.Generator full VAr rating: The full load rating (in VAr) of theset. This setting is used in conjunction with the full load rating(VAr) of the other sets in the system to determine the loadshare that this set will take (550 only).NOTE:- kW and Var sharing modes will automatically change to fixed export if an inputis configured to ‘Mains parallel mode’ and is active. The module will revert back to ‘Share’mode when the input is de-activated17.2.2 KW / KVAR LOAD RAMPLoad Control settingsFunctionLoad ramp rate: The rate at which the generator will beramped onto and off the load.NOTE:- The set will initially take load at the level setby load ramp minimum and will then increase it’s loadshare at this rate until either• All the sets have an equal share of the load (550module only)or• The generated power is equal to the setting for ‘loadparallel power’When the set is unloaded it will ramp down at this ratefrom the current load level to the level set by loadparallel ramp minimum before being removed from thebus (or mains supply).54DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

18 ON SITE COMMISSIONING18.1 DISABLING REMOTE ADJUSTMENT OF THE GOVERNOR / AVRDuring commissioning, the remote adjust signals to the governor and AVR must be disabled toensure that the only method of adjustment is the governor/AVRs main internal adjustment. Themethod of disabling this signal depends upon the method of interface between the 55x controllerand the governor / AVR:18.1.1 RAISE/LOWER INPUTSWhen using the 55x controllers internal raise/lower outputs to remotely adjust speed / voltage, theymust be disabled by one of the two following methods:a) Utilise the P810 configuration software to set the 55x auxiliary outputs to “unused” (taking careto make a backup copy of the module’s configuration before doing this).b) Remove the connections to the 55x controllers raise/lower outputs (taking care to correctlyinsulate the removed wire ends).18.1.2 P120 ANALOGUE GOVERNOR INTERFACE MODULEWhen using a P120 analogue governor interface module to control the governor, this interfacemodule must be partially disabled. To do this, remove the data connection cable from the “FromController” socket.After three seconds, the P120’s LED will begin to flash. This indicates loss of data communicationwith the 55x controller, and the P120 will automatically select its centre point, removing anycontrolling signal from the governor’s speed bias input.NOTE: - The DC supply must be correctly connected to the P120 module whenperforming this operation.18.1.3 P121 ANALOGUE AVR INTERFACE MODULEWhen using a P121 analogue AVR interface module to control the AVR, this interface module mustbe partially disabled. To do this, remove the data connection cable from the “From Controller”socket.When the generator begins producing electricity and supplies power to the P121 module, theP121’s LED will begin to flash. This indicates loss of data communication with the 55x controller,and the P121 will automatically select its centre point, removing any controlling signal from theAVRs voltage bias input.NOTE: - The AC supply must be correctly connected to the P121 module whenperforming this operation.NOTE: - The Link Lost LED will be extinguished until the generator begins to supplyvoltage to the ‘AC supply’ terminals of the P121 module.18.1.4 P122 DIGITAL RESISTANCE MODULEWhen using a P122 digital resistance module to control the governor/AVR, this interface modulemust be partially disabled. To do this, remove the data connection cable from the P122s “FromController” socket.The P122’s POWER LED will remain lit, but after three seconds the LINK LOST LED will begin toflash. This indicates loss of data communication with the 55x controller, and the P122 willautomatically select its centre point, removing any controlling signal from the AVRs/Governorsvoltage/speed bias input.NOTE: - The DC supply must be correctly connected to the P122 module whenperforming this operation.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 55

18.1.5 ELECTRONIC / MOTORISED POTENTIOMETERSWhen using an electronic or motorised potentiometer to remotely adjust the speed / voltage, thismust be disabled before adjusting the governor/AVRs datum point. The method of disabling variesbetween different equipment manufacturers. You should refer to the documentation provided withyour electronic / motorised potentiometer for details of how to achieve this.18.2 SETTING GOVERNOR SPEED AND AVR VOLTAGEOnce the remote adjustments have been disabled, the AVR and governor commissioninginstructions can be followed to set their datum point (speed and voltage with no load and noexternal adjustments). After this has been performed and correctly verified, the remote adjustmentconnections can be re-enabled by reversing the instructions previously followed.NOTE: - When setting the off load speed and voltage, use the 55x’s built ininstrumentation to verify the settings. Adjusting voltage to an accuracy of ±1V andfrequency to an accuracy of ±0.1Hz between the different sets will ease the process ofsetting up the load sharing parameters later.56DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

18.3 55X CONTROLLER COMMISSIONING ADJUSTMENTSThe P810 for Windows Software Recalibrate page gives access to a number of adjustableparameters on the Sync and Load control page. These items can be adjusted “live” while theengine is running to set up and finely tune the synchronising process.WARNING: - Until all synchronising adjustments have been satisfactorily completed,ensure the generator contactor/breaker is disabled. You can do this by either disabling thecontrollers contactor/breaker output using the P810 configuration software, or by simplyremoving the connections to the contactor/breaker. Ensure any disconnected wires aresuitably insulated.Synchronising lampsModern electronic techniques ensure the correct operation of the ‘check sync’ and load switchingprocess, but this operation depends upon the correct wiring of the bus and incoming generatorsupplies right through the system. This is the point that most errors are likely to creep in. It is veryimportant that wiring of the supplies is double and triple checked before the system is run for thefirst time.The inbuilt phase sequence / rotation protection goes some way to verify the wiring of the suppliesto the 55x controller. However, it is common practice to employ a secondary ‘sync check’ duringcommissioning to double check the correct connection of the supplies.The diagram to the left shows a busbar andincoming generator supply. The synchronisinglamps can be used as a simple ‘check sync’verification.When the lamps are dim, the supplies are readyfor paralleling.NOTE: - The lamps must be rated to atleast twice the system voltage. In thisexample, the supply voltage is 230V (line-Neutral). The lamps are 230V AC bulbs. Twoare connected in series to allow connectionto the supply. If the incoming generatorsupply is 180° out of phase with the bussupply, the voltage across the lamps wouldbe 460V (2 x 230V).WARNING! Before re-enabling the load switching device double check ALL wiringbetween the alternator output, the 55x controller and the synchronising lamps.Additionally, verify the correct operation of the synchronising process.NOTE: - When using the P120 interface to control the electronic governor controller, itis easy to verify its connections. When the set is running ‘off load’, simply turn the P120sSW1 switch clockwise one position. The engine speed should change slightly. Rememberto return the switch to its previous position before continuing.This procedure can only be applied to the alternator output voltage where the P121 isbeing used in conjunction with the AVR.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 57

18.3.1 MULTISET SETTINGS (NOT APPLICABLE TO MODEL 555, 556 OR 557)Multi Set settingsFunctionMultiSet comm’s (MSC) ID: Each controller inthe system must have a unique MultiSetcomm’s identifier number. If two or moremodules detect that they share the number withanother controller, this will generate an alarm onthe offending set(s) and these set(s) will beunable to start the engine until the MSC Ids areall unique.Genset run priority: This is the priority of thegenset when used in a MultiSet system. Thelowest number denotes the highest priority andif that set is not running on load when required,the next highest priority set will take over. If lesssets are required, priority will be given to setswith lower numbers (higher priority) and lowerpriority sets will be stopped until the requirednumber are left powering the load. This valuecan also be changed from the module’s fascia.See P550 operators manual for details of this.58DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

18.3.2 VIEWING THE 55X SYNCHROSCOPE INSTRUMENTSetting up the synchroniser and voltage matcher is made easier by viewing the 55x Synchroscopedisplay. This can be viewed on the Generator Settings page of the 55x controller'’instrumentation…To see this, press the ‘page’ button…Until the LED above the generator icon on the550/555/557 is lit:Or the LED above the mains icon on the 556is litThe display will display “Generator Settings” for a short time, before displaying the first generatorinstrument.The synchroscope display is the ‘last’ instrument in the list of generator instruments…Press the ‘previous instrument’ button…Until the synchroscope display is shown :Hz +2.9 V +0.2DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 59

18.3.3 SYNCHROSCOPE OPERATIONDisplayDetailThe Initial stage of the Synchronisingdisplay will only show the differencebetween the Mains/Bus Supply and theGenerator Output. Here the display isshowing a frequency difference of+2.9Hz. The generating set frequencyis too high (indicated by the up arrow)and will be automatically reduced. Thevoltage is +0.2 volts high, but is withinthe limits set for RMS check syncvoltage (shown by the tick symbol).Once the difference between thebus/mains supply and the Generatoroutput has been reduced, the‘Synchroscope’ display will becomeactive. The moving indicator will rollfrom left to right or right to leftdepending on the polarity of thedifference between the Mains/bussupply and the generator output. Agenerator frequency greater than themains/bus frequency will cause theindicator to move from left to right (andvice-versa).Synchronising will only occur when boththe frequency and the voltagedifferences are within acceptable limits– Indicated by ‘Tick’ marks on the top ofthe display. Then the moving bardisplay will show the phase of thesupplies. Synchronising will nowcease, as the voltage and frequencyare within the check synch window. Asthe phase changes, the indicator willmove across the display.The picture to the left shows theposition of the phase indicator relativeto the phase of the two supplies. Forinstance when the phase is 0° or 360°(supplies in synchronism), the indicatordot is in the middle of the display, withinthe check sync window. When thephase is 180°, the indicator is at theextreme left or right of the display, thefurthest point away from the check syncwindow).When the phase falls within the checksync window, the indicator appears‘locked’ between the bars of the phasecheck sync window. At this time, thecommand to close the contactor /breaker is given. Should synchronismbe broken (i.e. the load switch does notoperate) then the indicator will pass outof the synchronising window and the‘locked’ indication will clear.60DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

18.3.4 FREQUENCY SYNCHRONISER SETUPWARNING: - Until all synchronising adjustments have been satisfactorily completed,ensure the generator contactor/breaker is disabled. You can do this by either disabling thecontrollers contactor/breaker output using the P810 configuration software, or by simplyremoving the connections to the contactor/breaker. Ensure any disconnected wires aresuitably insulated.The method of setting up the 55x synchroniser depends upon the interface method between the55x controller and the AVR/Governor.If your interface method uses the internal 55x raise/lower relays or the P122 digital resistancemodule, then you will use the ‘pulse’ scheme.If your interface method uses the P120 / P121 analogue interface module, then you will use the‘analogue’ scheme.NOTE: - There are four possible combinations of interface method:1) P122 module (or internal raise/lower relays) to interface to governor and AVR (bothusing the ‘pulse scheme’)2) P122 module (or internal raise/lower speed relays) to interface to governor (‘pulse’scheme) and P121 module to interface to AVR (‘analogue’ scheme).3) P120 module to interface to governor (‘analogue’ scheme) and P122 module (orinternal raise/lower voltage relays) to interface to AVR.4) P120 module to interface to governor and P121 module to interface to AVR (both usingthe ‘analogue scheme’)DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 61

Synchroniser / Volts Match SettingsFunctionSlip frequency: The difference betweengenerator frequency and the bus/mainsfrequency.The 55x controller will adjust engine speed untilthe frequency difference matches the slipfrequency. The phase of the supplies will thendrift in and out of synchronism at a rate of 1/slipfrequencytimes per second.I.e. for Slip frequency of 0.2Hz, the supplies willbe in phase once every five seconds.Pulse rate (Not applicable when using P120governor interface module)The number of raise/lower changes per secondof the P122 interface or 55x raise / lower relayoutputs.Pulse length (Not applicable when using P120governor interface module)The length of raise/lower pulses of the P122interface or 55x raise / lower relay outputs.Gain / Stability: In general, a lower settingresults in a slow voltage matching process, buttoo high a setting may cause instability(hunting). If this occurs, lower the stabilitysetting. If this has no effect, lower the gainsetting.NOTE: - Gain setting only applicablewhen using P120 governor interfacemodule.NOTE: - Start with gain and stability at the minimum settings. Increase gain until theengine speed becomes unstable, then half the gain setting.Now increase the stability setting until the engine speed again becomes unstable, thenlower a little.You may need to perform the synchronising process a number of times to see the effect ofyour changes. You can also ‘knock’ the governor actuator, or change the ‘slip frequency’setting to disturb the engine speed and force the controller into making further changes.NOTE: - As shown in the ‘graph’ images above, correct setting of gain/stability isachieved when the engine speed ‘overshoots’ it’s target two or three times before settling.Less undershoot will result in a slower synchronising process. More overshoots will leadto an unstable engine speed.62DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

18.3.5 VOLTAGE MATCHING SETUPSynchroniser / Volts Match SettingsFunctionPulse rate (Not applicable when using P120governor interface module)The number of raise/lower changes per secondof the P122 interface or 55x raise / lower relayoutputs.Pulse length (Not applicable when using P120governor interface module)The length of raise/lower pulses of the P122interface or 55x raise / lower relay outputs.Gain / Stability: In general, a lower settingresults in a slow voltage matching process, buttoo high a setting may cause instability(hunting). If this occurs, lower the stabilitysetting. If this has no effect, lower the gainsetting.NOTE: - Gain setting only applicablewhen using P121 AVR interface module.NOTE: - Start with gain and stability at the minimum settings. Increase gain until thegenerator voltage becomes unstable, then half the gain setting.Now increase the stability setting until the voltage again becomes unstable, then lower alittle.You may need to perform the voltage-matching process a number of times to see the effectof your changes.NOTE: - As shown in the ‘graph’ images above, correct setting of gain/stability isachieved when the voltage ‘overshoots’ it’s target two or three times before settling.Less undershoot will result in a slower voltage-matching process. More overshoots willlead to an unstable voltage.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 63

18.3.6 LOAD SHARE / CONTROL SETUPLoad Control SettingsFunctionGain and stability: In general, a lower setting results inslower changes to the load control. Too high a setting maycause instability in changes to the load control. If this occurs,lower the settings.NOTE: - Start with gain and stability at the minimum settings. Increase gain until theengine speed becomes unstable, then half the gain setting.Now increase the stability setting until the engine speed again becomes unstable, thenlower a little.You may need to change load levels a number of times to see the effect of your changes.You can also ‘knock’ the governor actuator, or change the ‘load parallel power’ setting(555/7 only) to disturb the load-share process and ‘force’ the controller into makingfurther changes.NOTE: - As shown in the ‘graph’ images above, correct setting of gain/stability isachieved when the %age load share passes it’s target two or three times before settling.When using multiple 550 controllers, stability is considered to once the %age share of allcontrollers in the system are less than 2% apart while no load changes take place, this isconsidered to be stable.If the %age load share passes it’s target twice or less before achieving stability, this isconsidered to be too slow. If it passes its target more than 2 or three will lead to anunstable load share between controllers which could ultimately lead to the set beingreversed powered by the bus (or utility supply on 555/7) and in the case of multiplegenerators being on the bus, may result in the set reverse powering one or more of theother generators on the bus.64DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

Load Level SettingsFunctionLoad parallel ramp minimum: The level to which thegenerator will ramp down to before being removed from thebus (mains supply in the case of 555/7).Load parallel power: The amount of power that the set willproduce when used in ‘Load level control’ mode. (Onlyavailable on 555/7 when Load Control Mode is set to LoadLevel Control)NOTE: - If the load level is below this setting, then thegenerator will export power to the mains grid. If noexport agreement with the Electricity Supply Companyexists, a reverse power unit on the incoming mainssupply should be utilised to prevent this situationoccurring.KVAr control: The amount of reactive power that the set willproduce when used in ‘load level control’ mode. . (Onlyavailable on 555/7 when Reactive Load Control Mode is set toLoad Level Control)Pf control: The power factor that the set will maintain whenused in ‘load level control’ mode. . (Only available on 555/7when Reactive Load Control Mode is set to Load LevelControl)NOTE:- At low load levels it may not be possible tomaintain the power factor.DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 65

18.3.7 MAKING REACTIVE POWER SHARING ADJUSTMENTS (550 MULTISET WITHNO AVR CONTROL)In this situation, as reactive power sharing is controlled purely by the generator’s AVR, it is theAVR voltage setting that must be adjusted to make any changes to the kVAr (reactive power)share.Example: With two sets in parallel, and one generator is supplying more VAr than the other. Thevoltage setting of the AVRs must be adjusted slightly to transfer the share from one generator tothe other. Increasing the setting on one AVR has the effect of increasing that set’s share of thereactive power, and decreasing the other set(s) share of reactive power.As this will have slightly altered the generators output voltage, it should be checked to ensure thatit has not been altered by too much. This procedure may have to be conducted more than once,possibly adjusting the other AVR(s) a little the following times to ensure a suitable reactive loadshare between the sets, while maintaining a suitable off load generator voltage.NOTE: - Many AVRs have only a single turn potentiometer for adjusting the outputvoltage. This has the effect of making reactive power sharing adjustments very sensitive.Care should be taken to make small changes to the adjustment, and to ensure that thevoltage / VAr is stable (i.e. not changing) before further changes are made.NOTE: - Ensure the “Check voltage” window is suitably set to allow voltages to matcheven when the generator(s) already on the bus are loaded. Remember that a loadedgenerator with an AVR droop kit will give a lower voltage than an unloaded generator.66DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

19 TYPICAL CONNECTIONS19.1 TYPICAL CONNECTIONS FOR A SINGLE 550 LOAD SHARE UNIT.TO OTHER 550 MSC CONNECTIONSMAX 250 METERS120 OHM SCREENED CABLETHE FIRST AND LAST UNITS MSCMUST BE FITTED WITH A 120 OHMRESISTOR ACROSS Mh AND MiDSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 67

19.2 TYPICAL CONNECTIONS FOR TWO 550 LOAD SHARE MODULES INPARALLELTO OTH ER 550 MSC C ONNECTION SMAX 250 M ETERS120 OHM SCREENED CABLETHE FIR ST AND LAST UN ITS MSCMUST BE F ITTED WITH A 120 OHMRESIST OR ACR O SS M h AND Mi68DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

19.3 TYPICAL CONNECTIONS FOR A 556TO OTHER 550 MSC CONNECTIONSMAX 250 METERS120 OHM SCREENED CABLETHE FIRST AND LAST UNITS MSCMUST BE FITTED WITH A 120 OHMRESISTOR ACROSS Mh AND MiDSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 69

19.4 TYPICAL SINGLE LINE DIAGRAM OF MULTI SET MAINS FAIL70DSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM

20 APPENDICES20.1 530 AS MAINS / GENERATOR BUS TRANSFER SWITCHUsing DSE model 530 to control the generator busload switching device of a MultiSet system (2-16controllers), allows the 550 controller to be used as aMultiSet backup to the mains supply. Upon a mainssupply failure, the 530 instructs all sets in the systemto start, the first closing onto the dead bus, with theremaining sets synchronising and paralleling with it.When all ‘available’ sets are on the generator bus, asignal is made to the 530’s “Aux. generator ready”input, allowing the 530 to changeover the transferswitch. This signal comes from an auxiliary output oneach 550 module (outputs paralleled together),configured to All available sets on bus.Any sets not in the ‘Auto’ mode, or with shutdownfaults present will not be ‘available’ so are not requiredto be on the bus before the signal to close thegenerator bus switching device is given.NOTE: - When using version 3 or earlier model 550, the All available sets on bus outputsource is not available, this feature is included in version 4 or higher model 550s. Howevera similar function can be achieved using external logic derived from a module outputconfigured to System healthy and an auxiliary contact on each generator’s bus contactor /breaker to indicate availability on the bus (see diagram below).NB. For "Not Healthy" signal, configure a 55x output to"De-energise", "System Healthy"Battery positiveGen1 not healthyGen1 Contactor AuxiliaryGen2 not healthyGen2 Contactor AuxiliaryGen3 not healthyGen3 Contactor AuxiliaryGen bus interconnector auxiliary10 - Aux Gen ReadyDSE Model 530Close Generator output31 32Load LGen bus contactorNB only one pole of the four pole Gen buscontactor is shown for clarityGen bus NGen bus LDSE Guide to Synchronising & Load Sharing PART 1 ISSUE5 18/3/04 AM 71