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❏ Installation and maintenance data❏ catalog 130 C 93/01 BMicroTech TMReciprocating chiller controllerfor ALR & WHR units

MicroTech130 C - 93/01 B - page 2MicroTech control systemWARNING!ELECTRIC SHOCK HAZARD. MAY CAUSE PERSONALINJURY OR EQUIPMENT DAMAGE.Equipment must be properly grounded. Connections andservice to the MicroTech control panel must only beperformed by personnel knowledgable in the operation ofthe equipment being controlled.IntroductionThis manual provides installation, set up and troubleshooting information. For the MicroTech controller asprovided on all ALR and WHR models of McQuay reciprocatingchillers. A Monitor Program with separate literature,is available for computer monitoring and networking.This manual is given as a supplement to the appropriatechiller installation manual for unit application informationas well as water and refrigerant piping details.NOTICEThis equipment generates, uses and can radiate radiofrequency energy. If not installed and used in accordancewith the instruction manual, may cause interference toradio communications. It has been tested and found tocomply with the limits for a Class A digital device, pursuantto part 15 or the FCC Rules.These limits are designed to provide reasonable protectionagainst harmful interference when the equipment isoperated in a commercial environment.Operation of this equipment in a residential area is likely tocause harmful interference in which case the user will berequired to correct the interference at his own expense.CAUTION!EXCESSIVE MOISTURE IN THE CONTROL PANELCAN CAUSE HAZARDOUS WORKING CONDITIONSAND IMPROPER EQUIPMENT OPERATION.When servicing equipment during rainy weatherconditions, the electrical components in the main controlpanel must be protected form the weather.CAUTION!EXTREME TEMPERATURE HAZARD. CAN CAUSEDAMAGE TO SYSTEM COMPONENTS.The MicroTech controller is designed to operate within anambient temperature range of - 29°C to 52°C with a nonoperatingrange of - 40°C to 60°C. The controller isdesigned for 95% relative humidity (non condensing).CAUTION!THE MICROTECH CONTROL PANEL CONTAINSSTATIC SENSITIVE COMPONENTS. A STATICDISCHARGE WHILE HANDLING ELECTRONICCIRCUIT BOARDS CAN CAUSE DAMAGE TO THECOMPONENTS.To prevent such damage during service involving boardreplacement, McQuay recommends discharging any staticelectrical charge by touching the bare metal inside thepanel before performing any service work.GENERAL DESCRIPTIONThe MicroTech Unit Control Panel, available on someMcQuay ALR and WHR products, contains a Model 250(used on the units with two compressors) or Model 280(used on the units with 3 and 4 compressors) microprocessorbased controller which provides all monitoring andcontrol functions required for the safe efficient operation ofthe unit. The operator can monitor all operating conditionsby using the panels built in 2 line by 16 character displayand keypad or by using an IBM compatible computerrunning McQuay Monitor software. In addition to providingall normal operating controls, the MicroTech controllermonitors all safety devices on the unit and will shut thesystem down and close a set of alarm contactors if analarm condition develops. Important operating conditionsat the time an alarm occurs are retained in the controllersmemory to aid in troubleshooting and analysis.The system is protected by a simple password schemewhich only allows access by authorized personnel. A validpasswork must be entered into the panel keypad by theoperator before any setpoints may be altered.FEATURES OF THE MICROTECH CONTROL PANEL• Enhanced head pressure control on air cooled units.• 12 key keypad for adjusting chiller water temperatureset-points, low water temperature cutout, high pressurecutout, suction pressure cutout, and freeze protection. Theoperator can use the keypad to monitor various operatingconditions, setpoints or alarm messages.• Easy-to-read 2 line by 16 character display for readout ofoperating temperature and pressure, operating modes oralarm messages.• Security password protection against unauthorizedchanging of setpoints and other control parameters.• Complete diagnostic to inform the operator of pre-alarmsand alarms. All alarms are time and date stamped so thereis no guessing of when the alarm condition occurred. Inaddition, some operating conditions that existed at theinstant of shutdown can be recalled to aid in isolating thecause of the problem.• Soft Loading feature to reduce electrical consumptionand peak demand charges during loop pull-down.• Easy integration into building automatic systems via

MicroTech130 C - 93/01 B - page 3separate 4-20 milliamp signals for chilled water reset anddemand limiting.• Internal time-clock for on/off scheduling.• Communications capabilities for local system monitoring,changing of setpoints, trend logging, remote reset, alarmand event detection via IBM compatible PC. The optionalmodem kit supports the same features from an off-site PCrunning the McQuay Monitor software.• Manual control mode to override automatic unit staging.Useful for system checkout.COMPONENTS DATAThe major component parts to the MicroTech controllerare described in the following section and are:1. MICROPROCESSOR CONTROL BOARD2. ANALOG/DIGITAL INPUT (ADI) BOARD3. OUTPUT BOARD AND EXPANSION BOARD4. KEYPAD/DISPLAY5. PRESSURE TRANSDUCERS6. THERMISTOR SENSORSAll MicroTech components are mounted inside the controlsection side of the unit's control cabinet. The individualcomponents are interconnected by ribbon cable, shieldedmulticonductor cables or discrete wiring. Power supply forthe unit system is 110V provided by T-1 transformer (Furnishedby McQuay), while the power supply for the microprocessorsystem is provided by T-2 and T-3 transformers.All field wiring must enter the control cabinet throughknockouts provided and is terminated on field wiring M1Terminal.The standard ALR keypad/display is located inside thecontrol cabinet for protection from the weather while theback light WHR keypad/display is accessible through theexterior of the control cabinet.control software and performing internal hardware tests.Figure 2 - MicroTech Control boardBAKEY PAD / LCD DISPLAYRUNNINGRESETACTIVEHGRYCHI LOADDRESSCPUSTATUSOUTPUT 0EXPANSIONBUSDIGITAL INPUT2. After the self-check period, the RESET LED will turn offand the green RUNNING LED will illuminate indicating thecontroller's circuitry and software are operating correctly.NOTE: If the RESET LED stays on or the RUNNING LEDfails to illuminate disconnect the controller power byopening circuit breaker Q9 and re-check the field wiring.Observe the controller's LED's while re-connecting powerby Dimensioni closing Q9 (mm) switch.If the RUNNING LED still does not turn on, refer to thetroubleshooting section in this manual.3. The amber OUTPUT Ø ACTIVE LED is associated withthe external alarm output on the solid-state relay boardand will be illuminated during any alarm conditions.DGFUSEEPORTA A PORTA BCOMMUNICATIONS(fuse bussman MCR-VA)DIGITAL INPUTANALOG INPUTFF1. MICROPROCESSOR CONTROL BOARDThe microprocessor control board is the core processor ofthe MicroTech Controller. The Model 250 (used on ALRand WHR with 2 compressors) and the 280 (used on ALRand WHR with 3 and 4 compressors), Control Boardcontains the electronic hardware and software required tomonitor and control the unit. The controller recieves inputfrom the ADI board and send commands to the OutputBoard to maintain the units optimum operating mode forthe current condition.The major components on the controller are:A) Three status light (LED - Light Emitting Diodes) Pos. Aon the controller which will indicate the microprocessor'soperating condition. The interpretation of the ON/OFFcondition of this LED is shown in Tables 1 and 2.The proper sequence that these LED's follows uponpowering up the MicroTech controller is as follows:1. The RED LED turns on remaining on for approximately3 seconds after applying power to the controller.During this period, the microprocessor is checking theTable 1 Green and red microprocessor status led'sGreen Red IndicationOffOffOffOn*No power to controllerSelf-test failure controller defectiveOn Off Microprocessor operating normally(*) For longer than 5 secondsTable 2 Amber microprocessor status ledLed statusIndicationOn continuoslyOffOnNormal operationLoss of power to controller or applicationprogram not executing

MicroTech130 C - 93/01 B - page 6input No W.D. simb. Function Description & location Range Resolution6 Q19 Evaporator water temp. reset or when usedby McQuay "Ice" mode switch (optional)7 Q16 Demand limit or when used by McQuayEnergy saving switch (optional) in the unitswhit double speed compressor8 W108 Entering evaporator water temperature9 W109 Entering condenser water temp.(O.A. temp. for air cooled units)10 W110 Leaving condenser water temperature11/ Percent of total unit Amps (optional)12 W112 Suction temp. Circuit # 113 W113 Suction temp. Circuit # 214 W114 Liquid line temp. Circuit # 115 W115 Liquid line temp. Circuit # 2A 4 to 20 mA DC (supplied by others) a building 4 to 20 mA DC /automation system or temperature transmitterto reset the leaving chilled water setpoint. Theimpedance of the ADI board is 249 ohmsA 4 to 20 mA DC (supplied by others) a buildingautomation system to determine the maximumnumber of cool. stages which may be energizedThe impedance of the ADI board is 249 ohmsSensor is located in the entering chilled water -40 to 130°C 0.1°Cnozzle. The signal is used for monitoring andfor chilled water reset if selected. (see note 2)Sensor is located in the common entering -40 to 130°C 0.1°Ccondenser water nozzle or located under thecondenser coil as an outside air temp sensor forair cooled units ALR (see note 2)Sensor is located in the common enteringcondenser water nozzle.A current transformer and adjustable voltagedropping resistor located in the power side of0 to 4 VDC 1%the control box along with a voltage converterboard sends a DC signal proportional to totalmotor current to the microprocessor0 vdc = 0%, 4 vdc = 100%Sensor located to the Circ # 1-40 to 130°C 0.5°Csuction line measures refrigerant temperatureto calculate superheatSensor located to the Circ # 2suction line measures refrigerant temperatureto calculate superheatSensor located to the Circ # 1suction line measures refrigerant temperatureto calculate subcoolingSensor located to the Circ # 2suction line measures refrigerant temperatureto calculate subcoolingNote: the above analog input are common for Micro Control board model 250 & 280 ADI 16 & 24 equipped on the unit with two compressors both Copeland orits equipped with 3 &4 McQuay compressors.Table 4Analog input for WHR 225÷285 and ALR 210÷260 3 compressors unitAnalog input for WHR 210÷380 and ALR 285÷360 4 compressors unitinput NoW.D. simb.FunctionDescription & locationRangeResolution16W32 Evaporator pressure transducer Circ # 317 W42 Evaporator pressure transducer Circ # 4Sensor is located in the circuit 3 suction line 35 to 1015kPaUsed to determine suction saturated refrigerantpressure and temperature. This sensor alsoprovides refrigerant freeze protection for Circ # 3Sensor is located in the circuit 4 suction lineUsed to determine suction saturated refrigerantpressure and temperature. This sensor alsoprovides refrigerant freeze protection for Circ # 40,7 kPa

MicroTech130 C - 93/01 B - page 7input No W.D. simb. Function Description & location Range Resolution18 W32 Evaporator pressure transducer Circ # 3 Sensor is located in the Circ # 3 suction line 35 to 1015kPaUsed to determine suction saturated refrigerantpressure and temperature. This sensor alsoprovides refrigerant freeze protection for Circ # 317 W42 Evaporator pressure transducer Circ # 4 Sensor is located in the Circ # 4 suction lineUsed to determine suction saturated refrigerantpressure and temperature. This sensor alsoprovides refrigerant freeze protection for Circ # 418 W33 Condenser pressure transducer Circ #3 Sensor is located in the Circ #3 discharge line. 140 to 3150kPaUsed to determine saturated refrigerant pressuretemperature. This sensor provides software highpressure protection and head pressure control19 W43 Condenser pressure transducer Circ # 4 Sensor is located in the Circ #4 discharge line.Used to determine saturated refrigerant pressuretemperature. This sensor provides software highpressure protection and head pressure control20 W116 Suction temp. Circuit # 3Sensor located to the Circ # 3-40 to 130°Csuction line measures refrigerant temperatureto calculate superheat21 W117 Suction temp. Circuit # 4Sensor located to the Circ # 4suction line measures refrigerant temperatureto calculate superheat22 W118 Liquid line temp. Circuit # 3Sensor located to the Circ # 3suction line measures refrigerant temperatureto calculate subcooling23 W119 Liquid line temp. Circuit # 4Sensor located to the Circ # 4suction line measures refrigerant temperatureto calculate subcooling0,7 kPa3,5 kPa0.1°CThe above analog inputs are present only on the above units and are the conditions of the continuous tableNote: Sensor placement1) In the ALR 285÷360 having 2 evaporators and not common water connection, sensor W100 W108 for entering and leaving water temperatures areleft near to the outlet nozzle of the evaporator.Install the immersion well and the sensor bulb in the inlet and outlet chilled water common piping for the two evaporators.Insert heat conducting compound inside the well before installing the sensors.2) In the WHR units sensors W109 W110 for entering & leaving condenser water temperatures have to installed as explaned in point 1.See figure 5 for dimension of immersion well and sensorFigure 6 - Dimension of immersion well and sensor

MicroTech130 C - 93/01 B - page 82.2 CONTROLLER DIGITAL INPUTAll digital Inputs are 24 VAC at 7,5 VAC to 24 VAC digitalInput contacts are considered closed. Below 7,5 VAC, thecontacts are considered open. The 7,5 VAC threshold isthe voltage at which the opto coupler conducts.Note that each digital input has a red LED which isilluminated when the contacts are closed (24 VAC ispresent at board terminal).See Table below for details and operating characteristics.Table 5Digital input for WHR 045÷190 & ALR 035÷180 unitsInput & W.D. Circuit Contacts descriptionLED no simbolsDescriptionreferenceClosedOpen0F13Mechanical high pressure switchCirc # 1NormalHigh pressure1F11Oil differential pressure switchCompr # 1Low oil pressure2MP1Motor protection switchHigh compressor temp.3/Open//4/Open//5Q12System switchUnitUnit shutdown6F112Phase/voltage monitorP.V.M. alarm7Q13Pump down switchCirc # 1Manual pumpdown8F23Mechanical high pressure switchCirc # 2High pressure9F21Oil differential pressure switchCirc # 2Low oil pressure10MP2Motor protection switchHigh compressor temp.11/Open//12/Open//13Q21Remote stop switchUnitRunPumpdown & stop14F116Water flow switchNormalNo evaporator (cond) flow15Q14Pump down switchCirc # 2Manual pumpdownNote: These digital input are common for Micro control board model 250 ADI 16

MicroTech130 C - 93/01 B - page 9Table 6Digital input for WHR 210÷380 & ALR 210÷360 unitsInput & W.D. Circuit Contacts descriptionLED no simbolsDescriptionreferenceClosedOpen0F13Mechanical high pressure switchCirc # 1NormalHigh pressure1F11Oil differential pressure switchCompr # 1Low oil pressure2MP1Motor protection switchHigh compressor temp.3F31Oil differential pressure switchCompr # 3Low oil pressure4MP3Motor protection switchHigh compressor temp.5Q12System switchUnitUnit shut down6F112Phase /voltage monitorP.V.M. alarm7Q13Pump down switchCirc # 1Manual pumpdown8F23Mechanical high pressure switchCirc # 2High pressure9F21Oil differential pressure switchCompr # 2Low oil pressure10MP2Motor protection switchHigh compressor temp.11F41Oil differential pressure switchCompr # 4Low oil pressure12MP4Motor protection switchHigh compressor temp.13Q21Remote stop switchUnitRunPumpdown & stop14F116Water flow switchNormalNo evap (cond) flow15Q14Pump down switchCirc # 2Manual pump down16F33Mechanical high pressure switchCirc # 3High pressure17Q33Pump down switchLow oil pressure18F43Mechanical high pressure switchCirc # 4High pressure19Q34Pump down switchManual pump down2021F51-52F53-54Thermal overloadThermal overloadCompr # 1Dimensioni (mm)Compr # 2High power absorbedcompressor22F55-56Thermal overloadCompr # 323F57-58Thermal overloadCompr # 4Note: These digital input are common for Micro control board model 250 ADI 163. RELAY BOARD OUTPUTSAll of the MicroTech panel outputs are controlled by solidstaterelays which are driven by the model 250 or 280controller. The controller activates a solid-state relay bysending a "trigger" signal to the output board (See fig. 6)via the attached ribbon cable. The relay responds to thetrigger by lowering it's resistance which allows current toflow through it's "contacts". When the controller removesthe trigger signal, the relay's resistance becomes veryhigh, causing the current flow to stop. The outputs areindividually protected by a replacable 5 amp fuse mountedon the output board adjacent to each relay. Tables 8 to 12provide additional information about each output.

MicroTech130 C - 93/01 B - page 10Table 7WHR 045÷100 Relay board outputsdigitaloutputOutputDescription0123456789101112131415Alarm circuit & alarmChilled water pump relayCirc # 1 liquid solenoid valveCirc # 2 liquid solenoid valveCompr # 1 MCRCompr # 2 MCRCompr # 1 unloader # 1Compr # 2 unloader # 1Compr # 1 unloader # 2Compr # 2 unloader # 2Condenser water pump circ # 1OpenOpenCondenser water pump circ # 2OpenOpenFigure 7. Output board 16 positionFigure 8. Output board 24 position

MicroTech130 C - 93/01 B - page 11Table 8ALR 035÷095 Relay board outputsdigital Output Presence of the output relays on the boardoutputDescription 035-038-045-055 060-065 070-075-085 0950Alarm circuit & alarm1Chilled water pump relay2Circ # 1 liquid solenoid valve3Circ # 2 liquid solenoid valve4Compr # 1 MCR5Compr # 2 MCR6Compr # 1 unloader # 17Compr # 2 unloader # 18Compr # 1 unloader # 29Compr # 2 unloader # 210Condenser fan stage 1 circ # 1XXXX11Condenser fan stage 2 circ # 1XXX12Condenser fan stage 3 circ # 1XX13Condenser fan stage 1 circ # 2XXXX14Condenser fan stage 2 circ # 2XXX15Condenser fan stage 3 circ # 2XXTable 9WHR 105÷190 & ALR 100÷180 Relay board outputsdigital Output DescriptionoutputPart winding (PWS) unitDouble speed (2C) units01Alarm circuit & alarm contacts for remote indicationChilled water pump relay2Circ # 1 liquid solenoid valve3Circ # 2 liquid solenoid valve4Compr # 1 MCRCompr # 1 MCR - Low speed5Compr # 1 unloader # 1Compr # 1 MCR - High speed6Compr # 1 unloader # 2Compr # 1 unloader # 17Compr # 2 MCRCompr # 2 MCR - Low speed8Compr # 2 unloader # 1Compr # 2 MCR - High speed9Compr # 2 unloader # 2Compr # 2 unloader # 1Note: 1 Digital output number 10 through 15 are not used on these units2 Digital output number 6 and 9 are optional and present only when additional capacity reduction step are requiredThe above D.O. are common for WHR 105÷190 and ALR 100÷180 units. Following table shows the remaining outputs used on ALR units and are thecontinuous of the previous table

MicroTech130 C - 93/01 B - page 12Table 10 ALR 100÷180 Relay board outputs Presence of the output relays on the board10 Condenser fan stage 1 circ # 1 X X X X X11Condenser fan stage 2 circ # 1XXXXX12Condenser fan stage 3 circ # 1XXX13Condenser fan stage 1 circ # 2XXXXX14Condenser fan stage 2 circ # 2XXXXX15 Condenser fan stage 3 circ # 2XXX100 110130155180Table 11WHR 210÷380 & ALR 210÷360 Relay board outputsdigital Output DescriptionoutputPart winding (PWS) unitDouble speed (2C) units012345678910111213Alarm circuit & alarm contacts for remote indicationChilled water pump relayCirc # 1 liquid solenoid valveCompr # 1 MCRCompr # 1 - unloaderCircuit # 2 Liquid line solenoid valveCompr # 2 MCRCompr # 2 - unloaderCircuit # 3 Liquid line solenoid valveCompr # 3 MCRCompr # 3 - unloaderCircuit # 4 Liquid line solenoid valveCompr # 4 MCRCompr # 4 - unloaderCompressor # 1 - MCR low speedCompressor # 1 - MCR High speedCompressor # 2 - MCR low speedCompressor # 2 - MCR High speedCompressor # 3 - MCR low speedCompressor # 3 - MCR High speedCompressor # 4 - MCR low speedCompressor # 4 - MCR High speedThe above D.O. are common for WHR 210÷380 and ALR 210÷360 Following table shows the remaining outputs used on ALR units and are the continuous ofthe previous table

MicroTech130 C - 93/01 B - page 13Table 12ALR 210÷360 Relay board outputs14 Condenser fan stage 1 circ # 11516171819202122232425Condenser fan stage 2 circ # 1Condenser fan stage 3 circ # 1Condenser fan stage 1 circ # 2Condenser fan stage 2 circ # 2Condenser fan stage 3 circ # 2Condenser fan stage 1 circ # 3Condenser fan stage 2 circ # 3Condenser fan stage 3 circ # 3Condenser fan stage 1 circ # 4Condenser fan stage 2 circ # 4Condenser fan stage 3 circ # 43.2 Diox expansion boardThe model 280 controller on ALR 285÷360 units isequipped with an expansion board to accomodateadditional digital outputs which are allocated on 4 positionoutput board, required for four circuit applicationDimensioni (mm)

MicroTech130 C - 93/01 B - page 144. Keypad & DisplayGeneral descriptionThe information stored in the MicroTech controller can beviewed (one menu and one item a time) through a two lineby sixteen character LCD display.The current MENU is shown on the top line and the currentMENU ITEM on the bottom line of the display.The MicroTech keypad consist of twelwe pressuresensitive membrane switchs. This keys are used to stepthrough, access, and manipulate the information stored inthe MicroTech controller using a tree -like structure. Thekeypad key are divided into four groups, with two or fourkeys in each.These groups of keys and their functions are describedbelow.First group: CATEGORYCATEGORYThe keys in this group provide quickaccess to strategic menus throughout theSTATUSCONTROLALARMSSWITCHmenu tree-structure.This reduces the need to step through allthe menus, one by one, in order to reachthe designed menu.There are three categories which make upthe tree structure and are described below.Each Category is divided into Menu and each Menu intoMenu Item.STATUSKEY Pressing STATUS key at any time shift thedisplay to Menu # 1 related to Unit Status which is the firstmenu of the STATUS category.This provides information on the current and chilleroperating conditions.CONTROLKEY Pressing CONTROL key at any time shifts thedisplay to Menu # 13 (control mode) for units with twocompressors and to Menu # 19 for units with three & fourcompressors.This is the first menu of the control category, which providefor the input of all the unit control parameters changeablesthrough the keypad. These include cooling, compressorand condenser fan control parameters as well as timeschedules and alarm limits.ALARMSKEY Pressing ALARMS key at any time shifts thedisplay to Menu # 24 (Circuit 1 current alarm) for units withtwo compressors and to Menu # 30 for units with threeand four compressors. This is the first menu of the ALARMcategory and provide information regarding current andprevious alarm conditions.SWITCHKEY Pressing SWITCH key at any time toggles thedisplay beween the current menu (status/control) item andCATEGORYSTATUSCONTROL.... MENU Information ........ ITEM Information ....ALARMSSWITCHMENUPREV.NEXTITEMACTIONCLEARENTERthe related menu (control/status) item somewhere else inthe tree-structure. For example, if this key is pressed in aunit equipped with two compressors, while the current menuitem is Menu Item 4-A.1 ( Lvg Evap = 6,2°C) the displayshifts to Menu Item 14-A.1 (Lvg Evap Spts = 5,9°C).This provide for easy review of actual versus set point values.Menu structure directory on page 47, include a listing of allthe currently supported switching functions.MENUPREV.NEXTPREV.Second group: MENUThe keys in this group as for steppingfrom menu to menu in the menu treestructure.KEYPressing PREV. shift the display to theprevious menu.Note: When Menu # 1 is currently in the display (the firstmenu in the menu tree-structure) pressing PREV. causesan "end of menus" message to appear in the display.Pressing PREV. again causes the display to wrap aroundto the last menu in the tree-structure.NEXTKEY Pressing NEXT shift the display to the nextmenu.Note: When the last menu in the menu tree-structure iscurrently display, pressing NEXT causes an "end of menu"message to appear in the display. Pressing NEXT againcauses the display to wrap around to Menu # 1 that is thefirst menu in the menu tree-structure.ITEMPREV.NEXTPREV.NEXTINCR.DECR.Third group: ITEMThe keys in this group are for stepping

MicroTech130 C - 93/01 B - page 15PREV.from item within a menu.KEY Pressing PREV. shifts the display to theprevious items in a menu.Note: When the first item in a menu is currently in thedisplay, pressing PREV. causes an "end of items" messageto appear in the display pressing PREV. again causesthe displayNEXTto wrap around to the last item in the menu.KEY Pressing NEXT shifts the display to the nextitem in a menu.Note: when the last item in a menu is currently in thedisplay, pressing NEXT causes an "end of items" messageto appear in the display. Pressing NEXT again causesthe display to wrap around to the first item in the menuFourth group: ITEMACTIONThe keys in this group are for makingCLEARINCR. changes to the unit control parameter orfor cleaning alarm conditions.DECR.ENTERNote: before a change to a parameter canbe made or before an alarm can be cleaned,the display prompts the user with an "enter password"message.At this point, the password must be entered before theuser can continue with the action.PASSWORD INFORMATIONThe password for ALR and WHR units is always theENTER ENTER ENTER ENTERsuccessive pressing of the following ACTION group keys:Once this has beendone, the user can make changes to the menu itementries. After entering the correct password, the controllerwill allows a 5 minute time period during which theoperator may make any necessary set point adjustments.Any keypad activity will reset the timer for the full 5minutes so the password only needs to be entered onceper section.After 5 minutes of inactivity, the password access time willexpire providing protection against unauthorized users.INCR.KEY When changing the value of a menu itementry, pressing INCR. + shifts the menu item display line tothe next available selection or next higher values, continuingpressing this key cause to get to the upper limit ofthe value range and "high limit reached" message appearin the display.DECR.KEY When changing the value of a menu itementry, pressing DECR. - shifts the menu item display lineto the next previous available selection or the lower values,continuing pressing this key cause to get to the lowerlimit of the values range and "low limit reached" messageENTERappear in the display.KEY Once a change has been made the desiredvalue, pressing ENTER locks in the new value.CLEARKEY Pressing ALARMS followed by CLEAR clearsthe current alarm. Also when a change is made to a menuitem, pressing CLEAR returns the display to the originalvalue as long as ENTER has not yet been pressed.Note: the cause of an alarm should always be determinedand corrected before resetting the alarm through thekeypad.Example of keypad operationA) To change a control setpointAs an example of using keypad key fuctions, considerreprogramming the Leaving evaporator setpoint on ALR orWHR equipped with two compressors, from 7 to 6°C.This consists of changing the Menu Item 14-A.1 entry from7 to 6°C.Assume Menu # 1 Unit Status is currently in the display.The following key sequence is followed:1. Press the CATEGORY group CONTROL key one time.This switches the display to Menu # 13 (the first menu inthe CONTROL category).2. Press the MENU group NEXT key once. This shifts thedisplay to Menu Item 14-A.3. Press one of the ACTION group key one time. Thisprompts the user to enter the password.4. Enter the 4 character authorization password (four timesENTER key). After the password verified message,press the ACTION group DECR.- key. Note that the valuebegins to blink. Continue pressing the DECR.- key untilthe desired value is shown.5. Pressing the ACTION group ENTER key one time to setthe value. This stores the new entry into the MicroTechcontroller memory. Note the value stops to blinking.6. Pressing the CATEGORY group STATUS key thenshifts the display back to Menu # 1.Note: During the enter password procedure, pressing thewrong key causes an "Password Invalid" message appearin the display.B) To view and clear a current alarm1. Press the ALARM key Circuit # 1 Current Alarm isdisplayed.2. Press the CLEAR key. The alarm is cleared and normaloperation of Circuit # 1 is resumed.3. Press NEXT MENU key. Circuit # 2 Current Alarm isdisplayed.4. Repeat step 2 to CLEAR the alarm

MicroTech130 C - 93/01 B - page 165. Pressure transducerEvaporator transducers are selected for a specificoperating range and provide an output signal which isproportional to the sensors is 34 to 1000 kPa with aresolution of 0,1 psig. Condenser pressure sensors have arange of 138 to 3100 kPa and a resolution of 3 kPa. Thepressure transducers require an external 5 VDC powersupply to operate which is provided at field wiring terminal# 14. This connection should not be used to power anyadditional devices. The transducer output characteristicsare detailed in fig 9.Table 13 - MicroTech thermistor resistance & Testing°C-14-12-1018-6Ω VDC °C Ω VDC °C Ω20563184684,304,2320223747342516597 4,16 24 313414986 4,09 26 287313388 4,06 28 26312,652,5454669298632,43 58 8022,32 60 7462,21 62 694VDC1,091,030,970,910,86-4120493,923024182,1646450,81(5V DC ± 0.12)Output supply voltage VDC02543210-1000Output characteristicsEvaporator ref.Condenser ref.1000 1000 1000Pressure kPa1009080706050403020100Output (% supply voltage)-20246810121416181085797973,833,73885180063,633,537252 3,436577 3,325971 3,215427 3,14939 2,994500 2,874104 2,7632342219204236381879173140 159642 147444 136246 125948 116650 108052 100121,966681,811,7170721,62 741,54 761,45 781,37 801,3 821,22 841,16 86635620,770,725254910,680,64459 0,6430 0,57402 0,54377 0,51353 0,48331 0,45310 0,42Figure 9 condenser and evaporator transducers6. Thermistor sensorMicroTech use a negative temperature coefficientthermistor for temperature sensing. A normal sensor willmeasure 3392 ohms at 22,2°C between ground and 5VDC source from the micro control board.The voltage between these two resistance varies as theresistances of the resistance of the sensor varies, and thisvoltage is converted to temperature by the controller,table13 shows the variations of thermistor resistance withtemperature. Sensors are pre-mounted and connected tothe MicroTech wiring strip with shielded cable.• Entering and leaving condenser (if applicable) evaporatortemperature• Suction an liquid line temperature (provides direct displayof subcooling and superheat)• Ambient O.A. temperature.INSTALLATION AND MAINTENANCEThe controller is shipped factory tested and pre-configuredfor the type of unit to be controlled.METERV- +METERΩ- +BLACKWHITEADI-BOARDSGTHERMISTORBLACKWHITETHERMISTORSENSORS AND TRANSDUCERSSensors and Transducers are pre-mounted and connectedto the MicroTech field wiring strip with shielded cable.

MicroTech130 C - 93/01 B - page 17Figure 10 Typical Field WirinCONTROL WIRINGAll low voltage control wiring is installed, labeled andtested by the factory prior to shipment.INTERLOCK WIRINGAll interlock wiring to field devices such as flow switchesand pump starters is provided by the installing contractor.Refer to Figure 6 as well as the unit wiring schematics andtypical application drawings at the end of this manual fordetails.EXTERNAL ALARM CIRCUITThe MicroTech panel can activate an external alarmenergizing the solid state relay (output 0) When an alarmor pre-alarm condition is detected.The terminal N. 311 e 312 are available at the field wiringterminal to energize an external alarm device such as abell, light or relay. An alarm annunciator rated for amaximum load of 1,5 Amps at 110 VAC maximum.The solid state relay alarm signal is de-energized duringnormal operation and will energize on an alarm condition.During a pre-alarm condition, the alarm output will pulse ata rate of 5 seconds on, 4 seconds off.NOTE: The alarm signal is not active during a powerfailure and will not provide a "Loss of power" alarm.REMOTE 4-20 MILLIAMP SIGNALSSignals for chilled water reset and demand limit can beprovided by the customer and should be connected to theappropriate terminals on the field wiring strip inside thecontrol cabinet.

MicroTech130 C - 93/01 B - page 18CALIBRATIONThe control software is installed and tested by the factoryprior to shipping therefore no periodic calibration of thecontroller is required. All control and safety setpoints willbe checked and adjusted if necessary by the installingcontractor prior to starting the unit. The MicroTech controllercontains default setpoints which will be appropriate formost common installations. Refer to Control Menu sectionin this manual for a listing of the factory default settings.MODEM KITAn optional modem kit may be factory or field installed forremote monitoring of the chiller from an off-site PC runningthe McQuay Monitor software. The kit comes completewith modem, wiring harness and installation instructions.DIGITAL OUTPUTSDevices wired to the digital outputs would tipically be anoptional Chilled Water Pump control relay or an AlarmAnnunciator.The MicroTech output device is a normally open solid-staterelay with an on board, replaceable 5 amp fuse.The statusof all outputs are shown by individual red LED's for easeof determining output status.AUDIBLE ALARMIt is highly recommended that an audible alarm be wired tothe Alarm Output of the Reciprocating control panel sothat the operator is alerted to any alarm condition as soonas possible. This alarm output is de-energized during normaloperation or safety shutdown of a unit controller.FIELD WIRINGInterconnecting wiring for the reciprocating control panelmay consist of:- Power Winring-110 VAC- Analog Input Signals- Digital Input Signals- Communications to a Personal Computer- Telephone Line for Remote Modem AccessPOWER SUPPLIESThere are several internal power supplies used by thecontroller and its associated circuitry.The regulated 5 VDC power on terminal n. 14 is used tosupport the analog inputs on the ADI Board and shouldnot be used to operate any external devices. An unregulated12VDC power supply is available on field wiring terminaln. 336 and an unregulated 24VAC supply is providedat terminal n. 5.Both of these may be used for poweringexternal devices such as low current relays and light.Contact McQuay Service to discuss your applicationbefore making any connections to these terminals.DEMAND LIMIT, CHILLED WATER RESET SIGNALSThe optional demand limit and chilled water reset signalsare 4 to 20 milliamp DC signals. The resistive load used tocondition the milliamp signalsis a 249 ohm resistor factorymounted on the ADI Board.DIGITAL INPUT SIGNALSRemote contacts for all digital inputs such as the chilledwater flow switch and the remote start/stop switch must bedry contacts suitable for the 24VAC control signals fromthe reciprocating control panel.NOTE: DO NOT CONNECT 110 VAC CONTROLPOWER INTO THESE OR ANY OTHER CONNECTINGCIRCUITS.COMMUNICATION PORTSCommunication ports are provided on the MicroTechcontroller for connection to an IBM compatible computerfor local or remote system monitoring. All communicationnetwork wiring utilizes low voltage shielded twisted paircable. The network uses the RS 232C communicationstandard with a maximum cable lenght of 15 mt. See thePersonal Computer Specification section of this manual forspecific hardware requirements.TELEPHONE LINEFor Remote Modem Access, a voice quality, direct dialtelephone line is required if remote access and monitoringof the unit controller is desired. The phone line should beterminated with a standard RJ-11 modular phone plug.STARTUP AND SHUTDOWNPRE STARTUP1. With main disconnect open, check all electricalconnections in control panel and starter to be sure theyare tight and provide good electrical contact.Although connections are tightened at the factory, theymay have loosened enough in shipment to cause amalfunction.2. Check and inspect all water piping. Make sure flowdirection is correct and piping is made to correctconnection on evaporator and condenser.3. Open all water flow to the condenser and evaporator.4. Start manually evaporator condenser water pump.Check all piping for leaks. Vent the air from the evaporatorand condenser water circuit as well as from the entirewater system. The cooler circuits should contain clean,non-corrosive water.5. If water regulating valves are provided, connect theircapillary to the manual valves provided on the condensersand open the manual valves.

MicroTech130 C - 93/01 B - page 196. Turn the main power Q10 switch, the F120 transformercircuit breaker, auxiliary circuits Q9 circuit breaker, andemergency stop Q11 push bottom to "ON" position.This will energize crankcase heaters R1, R3, R4 thecompressor motor protector MP1, MP2, MP3, MP4 andthe R6 evaporator heater (only ALR units).Crankcase heaters have operate at least 12 hours prior tostart-up.Crankcase should be warm.Making sure Q12 system switch and pumpdown switchesQ13-Q14 and Q33-Q34 are on "OFF" position.The 24V T2 transformer provides power to the MicroTechcontroller and related components.With 24V power applied, the controller will check theposition of the front panel System Switch. If the switch is inthe "stop" position the chiller will remain off and the displaywill indicate the operating mode to be OFF:SystemSW.The controller will then check the PumpDown Switches. Ifeither switch is in the "stop" position, that circuit'soperating mode will be displayed as OFF:PumpDownSw.If the remote Start/Stop Switch is open, the chiller will beOFF:Remote Sw.The chiller may also be commanded off via thecommunications network if a separate RMS Panel isinstalled. The display will show OFF:RemoteComm if thisoperating mode is in effect.If an alarm condition exists which prevents normaloperation of both refrigerant circuits, the chiller will bedisabled and the display will indicate OFF:AllCompAlarm.Assuming none of the above "Off" conditions are true, thecontroller will examine the internal time schedule todetermine if the chiller should start.The operating mode will be OFF:TimeClock if the timeschedule indicates an "off" time period.7. Check compressor oil level. Prior to startup, then oillevel should cover at least one-third of the oil sightglass.8. Check pressure drop across evaporator and condenser,and see that water flow is correct per the design flow ratesand data on page 9.9. Check the actual line voltage to the unit to make sure itis the same as called for on the compressor nameplatewithin + 10% and that phase voltage unbalance does notexceed 2%.Verify that adequate power supply and capacity isavailable to handle load.10. Make sure all wiring and fuses are of the proper size.Also make sure all interlock wiring is completed perMcQuay diagrams.11. Verify that all mechanical and electrical inspections bycode authorities have been completed.12. Make sure all auxiliary load and control equipment isoperative and that an adeguate cooling load is availablefor initial startup.STARTUP1. Open the compressor suction and discharge shutoffvalves until backseated. Always replace valve seal caps.2. Open the manual liquid line shutoff valve.3. Check to see that the unit F120, Q9, Q11 switches arein the "off" position.4. Check to see that the pumpdown switches Q13-14 andQ33-34 are in the "manual pumpdown" position and thecontrol system switch Q12 is in the "off" position.5. Thtow the main power Q10 and control circuitdisconnects to the "on" position.6. Verify crankcase heaters have operated for at least 12hours prior to startup. Crankcase should be warm.7. Turn the unit main power Q10 switch to the "on"position.8. Turn the F120, Q9, Q11 switches to the "on" position.9. The MicroTech controller contains factory installeddefault setpoints which will be appropriate for mostcommon installations. Step through all the unit's setpointsby using the keypad/displayand adjust them as required tomeet the job specifications.The chiller is shipped with "Manual unit off" as defaultoperating mode to avoid improper operating mode by theoperator. Select automatic operation in the Control Menubefore to go on. Any alarms appearing on the displayshould be cleared at this time by pressing the CLEAR keyon the keypad/display.Watch the LED's on the input board, if no alarm is presentall LED's on the ADI board unless = 1, 3, 9, 11 referred tooil pressure switch and = 7, 15, 17, 19 referred to circuitsswitches must be "on" and see also output board todetermine the operating status of the controller's outputswhile performing the following system checks.Move the Q12 System Switch to the "on" position. LED = 5on the ADI Board will turn on and if the internal timeschedule indicates an "on" period, the chilled water pumpoutput will be activate. The keypad/display will show theunit status as OFF: PumpDnSw's.NOTE: The chilled water pump output will remain energizedanytime the chiller is enable. The pump output isdeenergized whenever the chiller is in an OFF Modeinitiated by the System Down Switches or Networkcommunicationbs. When the chiller shifts from a CoolingMode to one of these off Modes, the chilled water pumpoutput will remain energized for 60 seconds.This will maintain water flow through the evaporator duringpumpdown and prevent rapid cycling of the chilled waterpump.10. Move Q13, Q14, and Q33, Q34 circuit switches to the"on" position. LED's = 7, 15, 17, 19 on the ADI Board willilluminate. If none of "off" conditions are present theMicroTech Controller will initiate a start sequence andenergize the chilled water pump output relay.

MicroTech130 C - 93/01 B - page 20The chiller will remain in the Waiting For Flow mode untilthe field installed flow switches indicates the presence ofchilled water flow. If flow is not proven within 30 seconds,the alarm output will be turned on and the chiller willcontinue to wait for proof of chilled water flow.Once flow is established the controller will sample thechilled water temperature and compare it against theLeaving Chilled Water Setpoint, the Control

MicroTech130 C - 93/01 B - page 21LOW AMBIENT STARTIf the saturated condenser temperature is less than 15°C(1480 KPa) at the time of circuit startup, the low ambientstart logic will cause the following changes in the normalstartup sequence.The first compressor will start when the solenoid valve isopened regardless of whether the evaporator pressurehas risen above the LPCutln setpoint. The refrigerantfreeze protect setpoint will be ignored for 180 seconds toallow time for the refrigerant pressure to build. If at theconclusion of the 180 second timer the evaporatorpressure is still below the LPCutln setpoint, the circuit willshutdown and the alarm output be activiated.The chilled water freeze alarm setpoint is enforced duringlow ambient starts and will shut down the chiller if a waterfreeze condition is detected.If at any time during low ambient start the evaporatorpressure drops to 70 kPa the chiller will shut off and a "LoEvap Pressure" alarm will be generated.PUMPDOWN CONTROLPumpdown of each refrigeration circuit will always occurwhen the circuit is commanded from a "Cooling" mode toan "Off: Ready" mode. The pumpdown sequence closesthe solenoid valve and the lead compressor in the circuit isused to perform the pumpdown.The compressor is fully loaded during pumpdown ifunloaders are present. While in the units with doublespeed compressor the controllers shall pumpdown thecircuit in either high speed and low speed (which evercondition the circuit was in when the pumpdown requestwas made). An alarm condition in the refrigerant circuit willdisable the pumpdown sequence.Pumpdown will occur if the evaporator pressure is abovethe LPCutln pressure and stop when the pressure reachesthe LPCutOut pressure. If the evaporator pressure has notdropped to the LPCutOut setpoint after 180 seconds, thecontroller will stop all compressors and activate the alarmoutput. Alarm will be "Can't Pump Down".Note that pumpdown can be commanded by the operatorby moving the circuit switch from "ON" to "OFF". Whenmanual pumpdown is activated, the circuit will pump downonce and then shut off. No additional compressoroperation will occur even if the evaporator pressure climbsabove the LPCutln setpoint.When the switch is moved to the "Auto" position, the firstcompressor will start and the unit will stage up as requiredif the controller is calling for cooling. If cooling is notrequested , the circuits will pump down and thecompressors will stop.If the chiller is commanded Off by the Time Schedule,Remote Communications or the Remote Stop Switch, thechiller will pump down and stop when the evaporatorpressure falls to the LPCutOut Setpoint.In the event the evaporator pressure rises above theLPCutln Setpoint, the controller will initiate anotherpumpdown sequence. After the second pumpdown, thecontroller will allow only one additional pumpdown to occurevery 120 minutes if required.AIR COOLED HEAT RECOVERY UNITSHeat recovery operation is enabled only when condenserwater flow is verified by the field installed condenser flowswitch. With Q17 closed and on a call for heat, the fieldprovided heat recovery control switch closes initiating a 5minute time delay.After 5 minutes the time delay will close energizing K9relay. K9 will de-energize the condenser fans and energizesolenoid valves Y11, Y12, Y31 and Y41, rerouting thecompressor discharge gas to the heat recoverycondensers.Upon satisfying the heating demand, the heat recoverycontrol switch opens which will start the condenser fansand re-route the refrigerant back to the air cooledcondenser. KT16, 26, 36 and 46 will delay switch-over ofY20 for 20 seconds when entering heat recovery mode toallow time for the refrigerant charges to stablize.MENU DESCRIPTIONA description of each of the three structures, STATUS,CONTROL and ALRM is here given.For each structure are explanation of each menu is alsogiven

MicroTech130 C - 93/01 B - page 22STATUS MENUSMenu 's1 through 12 for ALR & WHR units equipped with 2 compressors, and 1 through 18 for ALR & WHR unitsequipped with 3 & 4 compressors. Provides chiller operating information and display of sensor readings. The items listedunder these stautus menus are affected by the settings under the associated control menus and are not directly adjustedvia keypad.STATUS MENU DESCRIPTIONS11. Unit StatusThe chiller operating status is displayed within this Menu.A1OFF: Manual ModeWhen the mode of the unit is "Manual Unit Off" (see Menu 13-A.1)note that all the outputs will be off thus no pump down will takeplace, and no operation of the chiller water pump. This is thedefault mode of operation when the unit is shipped or when newcode is down loaded into a unit.2OFF: System SwQ12 switch located in the front panel of the unit is in the OFFposition.3OFF: Remote Comm.Controller has been commanded to an off state via RemoteCommunications4OFF: Remote SwUpon start up the panel will check the "Remote Stop Switch" digitalinput. Note that from the factory, the unit will ship with a mechanicaljumper between 303-304 field terminals. If the switch is open,the controller will remain in the "OFF: Remote Switch" mode.5OFF: Time ClockUpon closure of the remote Stop switch the unit will assure an"OFF Time Schedule" mode. Note that if a customer wishes for theunit to run whenever the remote switch is closed, the eight-daytime clock must be set to start at 00:00 and stop at 23:59 for allday.6All Comp. AlarmThis is the mode which will be displayed when all circuits are inalarm condition which means no cooling is possible.7OFF: PumpDn Sw'sQ13;Q14-Q33 and Q34 pump down digital inputs for all circuits arein the "OFF" position, the mode of the chiller is "OFF: Pump DownSwitch's"8OFF: ReadyOFF Ready or Standby910StartingWait for FlowIf none of the above "OFF" conditions are true, the unit will attemptto start, this is a transition mode to tell the operator that thecontroller will attempt to start the unit.Once a start has been requested, the controller shall energize thechilled water pump and check for the presence of chilled waterflow via the normally open flow switch (connected betweenterminals 305-306) If flow is not present, the controller will stay inthe "Wait for Flow" mode until flow is established. This isconsidered to be a "warning" condition which will generate a prealarm.Loss off chilled water flow during chiller operation will causethe unit to log the alarm and return to the "Waiting for Flow" state.When chilled water flow has been re-established, the alarm will

MicroTech130 C - 93/01 B - page 231112Wait for LoadCool Stage UpWhen chilled water flow is established the controller will wait for aperiod of time equal to the "Load Delay" setpoint (Menu 15-D) todetermine if the chilled water loop is above the current chilledwater setpoint. If the leaving chilled water temperature is above theleaving chilled water setpoint (Menu 14-A) plus half of the Controlband (Menu 14-C) plus Startup Delta T (Menu 14-D), the controllerwill enter the Cool Staging mode otherwise the controller will waituntil the end of the currently scheduled run period.Example: If the leaving chilled water setpoint is 6°C and theControl Band is 1,6°C and the StartupD-T set point is 1,4°C. Theleaving chilled water temperature must be 6+0,8+1,4=8,2°C beforethe chiller will enablecool staging.Cool Stage DownThese are momentary operating modes indicating a stage-up orstage-down is being initiated by the controller.13Cool Staging #B141Manual CoolInter Stg = ### secThis the normal mode the chiller will be in while cooling. Thenumber of currently active cooling stages will be displayed. Thestage is only an indicator of system capacity and does not indicatewhich compressor or circuits are on.Note: that "Cool Stage O" means that compressors are currentlynot available to be energize due to anti-cycle timers. If the loaddrops, such that the chiller is at stage 1 and the leaving chilledwater temperature is below the leaving chilled water temp.Setpoint (Menu 14-A.1), less half of the Control Band (Menu 14-C),less Shut Down Delta T (Menu 14-E) the chiller will go from the"Cooling Starting" mode to the "Wait for flow" mode.2A12. Circ. # 1 StatusOFF: System SwThe current operating condition of refrigerant circuit # 1 isdisplayed whenever this menu is selected. There is only one itemcontained in this menu.2OFF: Manual modeSee Menu 1 - Item A-2See Menu 1 - Item A-13OFF: Alarm4OFF: Remote Comm.Off due to Alarm condition5OFF: Remote Sw.See Menu 1 - Item A-36OFF: PumpDownSwSee Menu 1 Item A-47OFF: CycleTime## minThe Circuit pumpdown switch Q13 is in the "OFF" position8OFF: ReadyOff due to Anti-cycle timers (Menu 16-C/16-D)See Menu 1 Item A-8

MicroTech130 C - 93/01 B - page 249101112Pumping DownOpen SolenoidBrine Start Cyc #Cooling % Cap = ###The circuit is in the process of pumping down, the solenoid valve isclosedA request has been made for the circuit to be energized forcooling, the solenoid valve is open and the controller is waiting forthe pressure to rise above the "LP OUT IN" Setpoint (Menu 22-A)Number of cycle (Menu 16-E) remaining in the circuit during initialstartup to reach normal sequence of operationCircuit is cooling, operating conditions are normal. The circuitpercent capacity is displayed3A3. Circ. # 2 StatusOFF: System SwThe operating staus of this refrigerant circuit displayed on the keypad/displayare the same description listed above for circuit No 144. Water temp'sDisplay all the water temperatureA 1Lvg Evap = ##.# °CDisplay the Evaporator Leaving Water TemperatureB231= Open= ShortEnt Evap = ###.# °CThe MicroTech controller has a built-in function which will identify adefective sensor. The two possible failure modes are as follows:"Open" = Open Sensor"Short" = Shorted Sensor2 3 See aboveDisplay the entering evaporator water temperatureC1Ent Cond = ###.# °CD2 3 See above1Lvg Cond = ###.# °CDisplay the entering Condenser water temperature (for sensorlocation see instruction on page ......)2 3 See above5A1235. Circ. # 1 Pres'sEvp ###.# KPa ###°C999+ n/a°COpen n/a°CThe circuit # 1 evaporator and condenser refrigerant pressurereadings are displayed under this menu.Display the saturated evaporator refrigerant pressure and thecorresponding evaporating temperature.Saturated evap. pressure exceeds 999 kPa.4Short n/a°CDisplay failure condition for the sensor.

MicroTech130 C - 93/01 B - page 25B 1Cond ###.# kPa ###°CDisplay the saturated condenser refrigerant pressure.23100 + n/a°CSaturated condenser refrigerant pressure exceeds 3100 kPa3Open n/a°CSee above4Short n/a°CC1Min Cond Pr = ### #Display the calculated minimum condenser pressureD1Max Cond Pr = ### #Display the calculated maximum condenser pressureNote: For more explanation refer to Head Pressure Control Sectionon Menu 17, the difference between there values is the dead bandto control the condenser fans6AD16. Circ # 2 Pres'sEvp ###.# kPa ### °CThe circuit # 2 Evaporator and condenser refrigerant pressurereadings are displayed under this menu. The calculated minimumand maximum condenser pressure values are also shownNote: For explanation of the Menu Item refer to previous menurelated to circuit # 177. Circ # 1Temp'sThe circuit # 1 refrigerant temperatures are displayed hereA 12B 12Satur Evap = ### °C= n/a °CSuction Line=###.#°C= OpenDisplay the Saturated Evaporating Temperature, calculated fromsaturated evap. pressureMeans that the temperature is not displayable, check evap.pressureDisplay the suction gas temperature3= ShortSuction line temperature sensor is not correctedC 12D 12E 12SuperHT = ##.# °C= n/aCondenser = ### °C= n/aCond Appr = ### °C= n/aSuction line temperature sensor is shortedDisplay the superheat calculatedDisplay the saturated Condensing temperature, calculated fromsaturated condenser pressureDisplay the condenser approach calculated as difference betweenleaving condenser water temperature and saturated condensing

MicroTech130 C - 93/01 B - page 26F1Liquid Line=###.#°CDisplay the liquid line temperature2= OpenLiquid line sensor is not corrected.G31= ShortSubCoolg = ##.# °CLiquid line sensor is shorted.2= n/aDisplay the subcooling in the condenser calculated as differencebetween saturated condensing temp less liquid line temperature,88. Circ.#2 Temp'sSaturEvap = # °CThe Circuit # 2 refrigerant temperature are displayed hereNote: For explanation of the Menu Item refer to previous menurelated to Circ # 19A9. Chiller RatedLoad Amps = ### %Display the present Amp draw of the chiller expressed as apercentage of the unit rated load Amps under full load condition(optional sensor)10AB10. Comp Run HoursComp # 1 Hi = ####Comp # 1 Lo = ####The total run hours for each compressor is available under thismenuNote: When the units are equipped with two speeds compressorboth of operating hours for Low and High speed are recorded.If the unit is equipped with PWS compressors the number of totalrun hours are displayed in the "Comp # 1 Hi="CComp # 2 Hi = ####DComp # 2 Lo = ####11ABC11. Compr StartsComp # 1 Hi = ####Comp # 1 Lo = ####Comp # 2 Hi = ####The total number of starts for each compressor is available underthis menuNote: When the units are equipped with two speed compressors,both of compressor starts from STOP to Low speed and from Lowto high speed are provided.If the unit is equipped with PWS compressors the number ofcompressor starts are displayed in the "Comp # 1 Hi ="DComp # 2 Lo = ####12A12. Outdoor AirO.A. = ###.# °CDisplays the current outdoor air temperature through the OATsensor installed on the unit

MicroTech130 C - 93/01 B - page 27CONTROL MENUSMenu's 13 through 23 for ALR & WHR units equipped with 2 compressors, and Menu's 19 through 29 for ALR & WHRunits equipped with 3 & 4 compressors, are the setpoint menu's. All adjustable control parameters and setpoints, timeschedules, control options, and alarm conditions are accessed through these menu's.CAUTION: Any changes to the followings parameters must be determined and implemented by qualified personnel witha through understanding of how these parameters affect the operation of the unit. Negligent or improper adjustment ofthese controls may result in damage to the unit or personal injury.CONTROL MENU DESCRIPTIONS13A 12313. Control ModeManual Unit OffAutomaticAuto Circ # 1 - Off # 2This menu allows the operator to choose one of several operatingmodes for the unitsThe unit is manually Off. The operator must change this status toanother explained below to start-up the units.Automatic Staging control, all circuits are enabled for operation.4Off Circ # 1 - Auto # 2Selecting this option as the operating mode, refrigerant circuit 2 islocked off while allowing Circuit 1 to stage automatically.5Manual StagingThis option allow the normal staging of refrigerant circuit 2, butcircuit 1 is locked out.B 1Manual Stage = ØNote: These manual setting are intended to aid in thetroubleshooting and should not be considered to be normaloperating modes. The equipment should not be left unattendedduring manual operation as some automatic controls are disabled.The chiller will remain in the manual mode until Automaticoperation is selected. Selecting Manual staging the operator willdetermine manually the number of Cooling Stages. In this operatingmode, the condenser fans are controlled by the MicroTech.14A14. Lvg EvapSptsLvg Evap = 6,1°CThe chilled water setpoint, control band and maximum pull downrate are adjusted from within this menu as well as chilled waterreset options and control ranges This is the chilled watertemperature that will be mantained if no reset options are in effect.B 1CResetLvg = 12,0°CCntr Band = 1,8°CReset Chilled water setpoint, will indicate the calculated chilledwater temperature to be mantained when one of the reset options(Menu # 14 G) is enabled.The control band is a function between the water temperature dropaccross the evaporator, at full load, and the maximum number ofcooling stages present in the unit, and defined as non staging areaof the control. Any time the sensor temperature, minimum timebetween stage (adjustable interstage time Menu 16 B) haselapsed, the next band limits, no staging will occur. McQuayrecomends Temperature the following drop accross formula the evaporator for calculating at full load (∆T) the minimumcontrol band setpoint: Maximum number of cooling stages of the unit

MicroTech130 C - 93/01 B - page 28DEStartUp D-T = 1,6°CShutDn D-T = 0,6°CThe decision to enable the first stage of cooling is controlled byStartup delta temp. setpoint. Once flow is established, thecontroller will sample the chilled water temperature. If the chilledwater temperature is above the leaving chilled water temperaturesetpoint plus half of the control band setpoint plus the adjustableStartup delta T, the controller will select the refrigerant circuit withthe lowest number of starts as the lead circuit and energize thefirst stage of cooling.FMaxPull Dn = 0,2°CIf the chiller is operating at minimum capacity (stage no 1) and thechilled water tempearture falls below the leaving chilled watersetpoint plus half of the control band setpoint plus the adjustableshutdown Delta T, the controller will shut off the chiller, enter the"Waiting for load mode" Menu # 1, and monitor the chiller watertemperature.G12Reset Opt = NoneReset Opt = ReturnThe maximum Pull down rate setpoint will prevent over shootingthe chilled water setpoint during initial startup. The controller willlimit the rate at which thechilled water temperatureis reduced based on anadjustable setpoint (typically0,3°C/min). Wheneverthe pulldown rate excedesthe setpoint, thecontroller will delay additionalstage cooling.EXAMPLE:Unit with two compressors• No of cooling stage = 4• Entering Evap watertemp. = 12°C at full loadTemp °C8,586,9 765,154,5Chart of Delta-temp. setpoint algorithm operationUpper C.B. limitLower C.B. limitInterstage timeStart-upDelta Temp.ControlBandHalfC.B.Shut downDelta Temp.4Time-min0 10 20 30 40 50 60 70 80 902FreezeStat - H2O Setpoint• Leaving Evap water temp. = 6°C at full load• ∆T = 6°C at full loadC.B. setpoint = 6/4 + 0,3 = 1,8°CStartup ∆T = 1,4°CShutdown ∆T = 0,6°CThe first stage of the unit during the startup, will be energizedwhen the water temperature is above the upper C.B. limit plus theStartup ∆T setpoint, if the interstage time has elapsed (point A).After the minimum time between stages has elapsed and theleaving water temperature is above the upper C.B. limit the nexthighest stage of cooling will be energized (point B). Only when theLvgEvap temp has dropped below the lower C.B. limit the unitstage down. This sequence will continue until the demand forcooling increase or decrease. Any time the evaporator leavingwater temperature is above the upper C.B. limit a stage will go"ON" and any time the water temp falls below the lower C.B. limit astage will go "OFF".Note: The value of the sum of Lvg Evap Spt plus 1/2 Control bandSetpoint plus Shutdown Delta temp Setpoint, must not be less thanor equal to 4°C to avoid freezing inside the evaporator.As part of the "Lvg Evap Spts" menu, the operator shall select thetype of reset of the leaving Evaporator temperature.No Reset will occur. This means that the water temperatureLeaving the evaporator will match to the "Lvg Evap Setpoint".ABCDBy setting "Return" as the reset mode, the leaving chilled water

MicroTech130 C - 93/01 B - page 29Remote ChW Reset10090% of maximum chilled water reset8070605040302010001 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20External DC milliAmp signal3Reset Opt = 4÷20mAThe controller resets the chilled water setpoint based on an external4 to 20 mA At 4 mA or less, no reset will occur. At 20 mA, thechilled water setpoint will be reset by an amount equal to the valuestored in the "Maximum reset setpoint" Menu # 14-I. The resetschedule is linear and may be calculated using the above figure.Note: When the unit is to be used for Ice storage, the chilled waterreset analog input is used by McQuay, installing Q19 switch.HI45Reset Opt = NetworkReset Opt = IceReset Sig = 15,2 mAMax Chw Reset = °CThe controller can also receive a reset signal from a MicroTechRMS Panel via communication port. Signal received shall bepercentage of maximum reset. Thus a 0% signal results in no resetand a 100% signal results in maximum reset.If the signal is to be used for Ice storage, the following step aretaken:1) Select "Ice" Option in this Menu2) Set the chilled water setpoint Menu # 14-A to the desired (night)ice morning setpoint i.e. T night = -7°C3) Establish the value of leaving chilled water setpoint during nonicebuilding mode (day operation) i.e. T day = +6°C4) Set the "Maximum chilled water reset " Menu # 14-I equal to theamount of the absolute values of above setpointMax ChWRst = 7 + 6 = 13°CNote: During the Ice building mode, compressor are fully loaded(high speed in that units where double speed compreessors areused), to guarantee compressor loading.This means the number of cooling stages will be divided into two.Display the Remote reset signalJReturn Spt = ##.# °CThe maximum chilled water reset setpoint is set to reflect the15AB15. Soft Load SptsTime left = 20 minSoft load = 20 minThe soft loading feature limits the number of coding stages whichmay be energized by the controller to prevent unnecessaryelectrical demand and possible overshoot of the desired leavingchilled water tempearture. Soft loading is typically used duringmorning startup.When the controller enters the "Cool staging" mode of operationthe controller will start a count down timer and "time left" indicateshow long the unit has been in the cool staging mode.This is the lenght of time soft loading will be in effect after the

MicroTech130 C - 93/01 B - page 30CDSoft load MaxStg = 4Load Delay = 15 secThis is the maximum number of cooling stages which my beenergized while soft loading is in effect.This is the time delay that the controller will wait during morningstartup, once the chilled water pump run, to determine if the chilledwater loop is above the current chilled water setpoint. If cooling isrequired at the end of this time delay, the first compressor will be16A116. Compr. SptLead Circ = AutoThis menu is used to set the lead/lag order of the refrigerantcircuits, and to set start/start and stop/start timers to provideprotection against compressor short cycling.2Lead Circ = # 1The controller will select the refrigerant circuit with the lowestnumber at total compressor starts as the lead. Automatic lead-lagmay be disabled by selecting the following:3Lead Circ = # 2The lead circuit is circuit # 1 or the lead circuit has hot gas bypassor when the unit has only 50% of heat recovery.BInterStg = 210 secThe lead circuit is circuit # 2CMin ST-ST = 15 minThe Interstage timer setpoint sets the delay time between currentcooling stage and the next stage up request. The stage down requesttime delay is a fixed ratio of the "InterStg" setpoint to preventthe chiller from over cooling the loop when the load change rapidly.DMin SP-ST = 5 minThis is the minimum Start-to-Start timesELTsolValveCyc = ØThis is the minimum Stop-to-Start timesThe two above interstage timer for compressors provide protectionagainst short cycling, and are enforced at all times (except whenmanually by the operator)17A17. Head Pres SptMinLift 35% =586 kPaThe head pressure control is performed only in the Air cooled unit,consists to control the condenser fans to mantain the lowestcondensing temperarture possible, and the highest unit efficiency.For each refrigerant circuit, the first stage of condenser fans will bewired in parallel with the compressor output so that they areenergized with the compressor. Each circuit has 3 additional digitaloutput available for refrigerant head pressure control.Each will energize an additional bank of condenser fans. Typicallyeach digital output controls one condenser fans, however in samecases the output may control two fans.Refer to table 24 for specification about number of condenser fansstage per refrigerant circuit to be controlled for each unit size, "Liftpressure" is defined as the difference between the saturatedcondensing pressure and the saturated evaporator pressure.The Minimum Lift -35% setpoint is the minimum differentialpressure of approximately 586 kPa to be mantained accross theexpansion valve when the unit is running at 35% or less ofcapacity.

MicroTech130 C - 93/01 B - page 31PressionekPastage 220001800stage 116001400120010008006004002000stage 0errore del gradino sup.Max press. condensaz.banda neutraMin press. condensaz.errore del gradino inf.Lift pressionestage 1Pressione evaporaz.TempoBMinLift 100%=966 kPaThe Minimum Lift-100% setpoint is the minimum differentialpressure to be maintained to accomodate the increased flowthrough the expansion valve when the unit is running at 100%capacity. Between 35% and 100% circuitcapacity, the controller will calculate the proper Lift pressure byLineary interpolating between these two end points.CDeadBandMult = 1,0The Lift Pressure dead band is a band of pressure differentialrange above the Minimum Lift pressure setpoint where thecontroller will attempt to stabilize the lift pressure and within whichno condenser fan staging will occur. This Dead band value isbased on the current unit capacity and the current number ofcondenser fans in operation. "Dead Band Multiplier" is a variablethat provide to adjust all dead bad's up or down in 10%increments. In general, increasing the Dead band multiplier willslow down the response of the condenser fans when a change incondenser pressure is defected. Decreasing the Dead bandmultiplier setpoint will speed up the condenser fan response to achange in condenser pressure.DStageUpErr = 2760When the head pressure moves outside of upper limit of the Deadband the controller will integrate the pressure error over time.When the integrated error exceeds the Stage Up Error Setpoint thecontroller will adjust the condenser the fan stage up to bring thehead pressure back within the Dead Band.EStageDnErr = 690When the head pressure moves outside of the Lower Circuit of theDead Band, the controller will integrate the pressure error overtime. When the integrated error exceds the stage down errorsetpoint the controller will stage down the condenser fan.18A18. Demand LimitsDemandLim = 2 StgThe controller will limit the total number of stages based onexternal 4 to 20 mA signal regardless of the amount of coolingactually required. Signal between 0 and 4 mA will enable all stagesto operate, while between 4 to 20 mA the maximum number ofactive stage, as shown in fig. 9.Demand limit setpoint defines the maximum number of coolingstages allows by an external 4÷20 mA signal

MicroTech130 C - 93/01 B - page 32Remote demand limit, 4-6-8 stage unitBDemand Sg = 20,0 mADisplay the actual demand limit signal level in milliamps.Figure next to, detail the effect that the remote demand limit signalwill have on the chiller capacity.Note: When the unit is equipped with the optional "Energy Saving"19 19. Clock SettingABTime = 10 : 25Date = 10 / 07 / 92The MicroTech controller uses an internal calendar and clock toprovide automatic operation for each day of the yearTIMECurrent minutesCurrent hourDATECurrent yearCurrent monthCurrent dayTo change the time once the "ClockSetting" Menu is displayed press theNext Item Keys.Values of current hour blink, pressINCR, DECR Key to change to thedesired value than press ENTER key toconfirm.After pressing the ENTER key to sethour, the cursor will advance to theminutes position on the display. Use theINCR, DECR, and ENTER key to setthe correct values.Press the NEXT ITEM key. The displayshow the current Day/Month/Year.If this information needs to be changed,follow the same procedure used to setthe TIME.

MicroTech130 C - 93/01 B - page 3320AB20. ScheduleOverride = 0.00 HrNMP Schedule = N/AC Mon 08 : 30 - 17 : 50D Tue 00 : 00 - 23 : 59E Wed 00 : 00 - 23 : 59F Sun 00 : 00 - 00 : 00This section will help you to set the Dayli START/STOP time forautomatic operation of the chiller.The controller shall allow a timed OVERIDE function which willplace the unit into an occuped time period for a programmableduration. Time units for override shall be in 15 minutes increments,up to 63,5 hours of override shall be available.If the chiller is a part of a MicroTech Network (i.e. centralized timescheduling from a Remote monitoring system), the controller shallignore the internal time schedule and start and stop accordingRMS time schedules (up totime schedule STOP allowed). TIME Defaultshall be N/A andchangeable up to 32.START TIMEMinutesHoursMinutesHoursPressing the NEXT MENU key and theNEXT ITEM key will advance thedisplay to the Daily TIME SCHEDULE.This is where the start and stop timesfor each day of the week will be setusing the 24 hour format. Beginingwith Monday use the INCR and DECRkeys to set the desired start and stoptime and press the ENTER key tostore the information in the controller.Press the NEXT ITEM key to advancethrough the remaining week days andHolidays Start/Stop timer.G Hol 00 : 00 - 00 : 0021A121. Holiday Sched.# 1 Date = NovUp to 14 holiday dates may be entered. When the MicroTechcontrollers surrent date maches a date set in the holiday schedule,the normal daily start/stop times are replaced by the holiday start/stop times which were set in the previous section.N2312# 1 Date = 29# 1 Dur = 1 Day# 14 Date = Dec# 14 Date = 23At the date prompt, use the INCR and DECR keys to set the firstholiday month and press ENTER to advance to the day position ofthe holiday.Press NEXT ITEM to advance to Holiday 1 Duration. If thescheduled holiday spans more than one day use the INCR andDECR keys to set the Holiday duration and press ENTER key tostore the information in the controller.Use NEXT ITEM key to set additional holiday dates and durationfor the entire year.3# 14 Dur = 4 Days22AB22. Alarm SptsLP CutIn = 414 kPaLP CutOut = 234 kPaThese are safety parameters factory setted according to unitspecification used to prevent damage to the unit.Low Pressure Cut In Setpoint is the value that determines startingof compressor. On a call for cooling the controller will open liquidline solenoid valve. When the evaporator pressure rises above the"LP CutIn" setpoint the first compressor will be started.CFrzStat = 372 kPaThe low Pressure CutOut setpoint determines the point at whichthe compressor will shut off during a pumpdown sequence.The Freezestat setpoint is a refrigerant freeze protection.

MicroTech130 C - 93/01 B - page 34DEFFrze H2O = 1.1 °CFreezeTim = 80 secHiPres = 2428 kPaThe Freeze H2O setpoint is a chilled water freeze protection.Note: We suggest to set this value 2,5÷3°C less than the resultantof the "Lvg Evap" (Menu 14-A) less half "Control Band" (Menu14-C) less "Shut Dn D-T" (Menu 14-E)The FreezeTime is a time delay setpoint to prevent nuisancetripout on momentary low suction pressureThis high pressure setpoint is the high condenser pressure controlledby software. If the condenser HiPres setpoint is exceded, thecontroller will shut off the chiller. Usually this setpoint should be seta minimum 1 bar less the Mechanical high Pressure switches.23 23. Misc SetupABCDType = Air CooledComp = Part WindingUnit Size = 130 - 150No. Stage = 4Several general operating characteristics are defined here. Thereare set at the factory prior to unit delivery and should not requireadjustment. The control software version number is displayed inthis menu.ALR = Air CooledType of unitWHR = Water CooledSpecifics which kind of compressormotor is installed on the unit togenerate the proper operating logicSpecifics the unit size to determine theright cooling capacity and staging logicCompr. type: Part WindingTwo SpeedUnit size: ALR WHR100 105110 125130 150155 175180 190Number of capacity stages presentin the unit.Note: Two additional step of capacityare available only on the unit equipped with two compressors.EFNo. Fan Stages = 3IDENT = CR2EM15BNumber of condenser fans to be controlled by MicroTechController software is factoryMcQuay 01/06/92 Date of shipmentinstalled and tested in each P/N 131090002 Part numberpanel, prior to shipment. S/N 1942Serial numberThe software is identified by a EOS 20.21 Operating system versionprogram code which is printedon a small label attached tothe controller.VER CR2EM15A Software VersionTypical software identification is a shown in the label below:Type of UnitC - Air or Water cooled chillerH - Air to water or water to water heat pumpType of compressorsR - Reciprocating compressorNumber &/or type of compressor1 - 2 Copeland compressors2 - 2 McQuay compressors4 - 3 or 4 McQuay compressorsLanguagesI - ItalianE - EnglishF - FrenchD - GermanP - SpanishS - SwedishUnit of MeasuresM - Metric SystemI - English SystemVersion of software (0,1,2,3,..........)Revision (O,A,B,C,D,.........)X X X X X XX X

MicroTech130 C - 93/01 B - page 35ALARM MENUSMenu's 24 through 27 for ALR & WHR units equipped with 2 compressors and 30 through 37 for ALR & WHR unitsequipped with 3 & 4 compressors, are used to display any alarm conditions which may be present in the unit. All alarmmessages are accompained by the date and time when the alarm occured. Important operating conditions at the time ofthe alarm are stored in the controller's memory and may be viewed within the following alarm menus.ALARM MENU DESCRIPTIONS24A1224. # 1 Curr AlarmNoneHi Cond Pres Stg HldIf refrigerant circuit # 1 is in an alarm condition the appropriatealarm message will be displayed here.No alarm conditions.The following alarms are "AUTOCLEAR" alarm, that meansAUTOMATIC RESET, in this condition the red light on the frontpanel and the alarm output Ø will blink up to the operatingcondition are restored.3Hi Cond Pres Stg Dwn"High Condenser Pressure Stage Hold" is displayed whencondenser pressure rise to within 210 kPa of "Hi Cond Pres"setpoint (Menu 22-F), the controller will override any request toincrease current capacity staging. This the controller will hold atthe current capacity stage until the pressure decrease below the a/m differential value.4Freese Prot Stg Dwn"High Condenser Pressure Stage Down" is displayed whencondenser pressure increase more than the above value getting towithin 140 kPa of "Hi Cond Pres" setpoint (Menu 22-F), thecontroller will automatically stage down every 10 sec. until thecondenser pressure fails below the 140 kPa band below the "HiCond Pres" setpoint.5Loss of Chw Flow"Freeze Protection Stage Down" displayed when the standardevaporator refrigerant pressure falls below the "FrzStat" setpoint(Menu 22-C), and this condition has been mantained for at least 30seconds.67Comp # 1 Mtr ProtectCompr # 1 therm Over"Loss of Chilled Water Flow" displayed when there is no flowtrough the evaporator due to the digital input signal from flowswitch. A time delay is combined to accomodate momentary lossof flow due to air bubbles, pressure fluctuations in the chilled waterpiping.This motor protect indicates a high motor temperature condition inthe units equipped with 3 & 4 compressors, and in the units with 2compressors indicates also motor overload. The entire circuit shallremain locked out the contacts remake.8Cant'Pump DownThermal Overload alarm condition. This available as separatealarm, only on the 3 & 4 compressors unit.Note: When thermal overload trips, reset must be done on thedevices.The following alarm are MANUAL reset, that means a shutdown of

MicroTech130 C - 93/01 B - page 3691011121314151617Freeze Stat ProtLow Evap PressureComp # 1 LowOil / PwrHi Cond PressureMech Hi PressureBad Evap Pres SenBad Cond Pres SenSystem AlarmConditionBad Phase/VoltageWater Freeze Prot"Freeze Stat Protection" is displayed when the saturated evaporatorrefrigerant pressure falls below " FrStat" setpoint (Menu 22-C)for a time period equal to "Freeze Time" setpoint (Menu 22-E)."Low Evaporator Pressure" is displayed when the saturatedevaporator refrigerant pressure is below the "LPCutOut" setpoint(Menu 22-B). This alarm will also occur if the evaporator pressuredrops to 70 kPa during low ambient start.Each compressor is equipped with an oil differential pressureswitch which closes when the differential between oil pressure atthe discharge of the compressor oil pump and the suctionpressure, reaches 0,9 bar in units equipped with Copelandcompressor and 2,1 bar in units equipped with McQuaycompressor. The controller will initiate a shutdown of allcompressors in a circuit should one of these compressors in thatcircuit loose adequate oil pressure. Loss of oil pressure is detectedwhen the oil pressure differential switch opens at 0,7 bar(Copeland) and 1,8 bar (McQuay) and this condition remains thetrue for more than 30 consecutive seconds. If the switch reclosesbefore 30 seconds has elapsed, the timer is reset.This high pressure cut out alarm condition is in responce to thesignal sent by the pressure transducer, this is a a software controlledsetpoint and alarm locks out the respective circuit until cleared.This is an alarm due to "Mechanical High Pressure switches". Thisdevice is required to satisfy, safety requirements. In all cases thehigh pressure condition will be detected first by the MicroTech "HiCond Pres" alarm. Setting are in accordance to unit installationand country rules.This alarm appear when Evaporator Pressure Transducer signal isshorted to ground or open.As above but reffered to condenser Pressure transducer.The following alarm are "System Alarm Condition" and are thosealarm which are common to all refrigerant circuits present in theunit, and requires all compressors to be locked out. The followingalarm condition are checked continuosly during all modes ofoperation by the controller. If one of the following alarm conditionsis detected, the mode of the controller will switch to "All CompAlarm" (Menu 1-A.6). The controller disable all compressorsoperating by turning off all compressor Enable Outputs. AlarmOutput # 0 will be turned on to notify the operator of the alarmcondition. The chiller must have the following system alarmconditions cleared before normal operation can resume.Upon detecting an opening of the normally closed "Phase VoltageMonitor" contacts, compressors are immediately de-energized bythe P.V.M. device (OPTIONAL), the controller shall alsoimmediately open compressor enabled outputs and show properdiagnostics.If the leaving chilled water temperature falls below the "Frze H2O"setpoint (Menu 22-D), the chiller is shut down and alarm conditionslogged.Note: These is no time delay, just one sampling of water at this lowtemperature will shut the unit down.

MicroTech130 C - 93/01 B - page 371819Bad Volt Ratio SenBad Lvg Water SenThe controller monitors the output of both internal 5VD powersupply and calculate their ratio. If the microprocessor is notreceiving a acceptable Volts ratio signal, the unit will be shut down.Defective Leaving temperature water sensor. Check both possiblefailure modes. A shorth or Open o this sensor.BMonitor OnlySensor@ 20 : 52 10/06/92Note: The MicroTech controller will shut down the chiller, loggingone of the above alarm condition, if one of the primary temperatureor pressure sensors provide information to the display but are notcritical to chiller operation. The microprocessor will not activate theexternal alarm contacts or the OutPut or the red light alarm in thefront panel, or shut down the unit if one of the "Monitoring only"sensors fails. The display will simply indicate "Short or Open onthe keypad/display for defective sensor.The monitoring only sensors include:• Compressor Suction Temperature• Evaporator Water Temperature reset Signal• Demand Limit Signal• Entering Evap Water Temperature• Entering Condenser water Temperature• Leaving Condenser water Temperature• Liquid Line TemperatureCDEvp 215 kPaCnd 1830 kPaAll alarm messages are accompained by the date and time whenthe alarm occured. Important operating conditions at the time ofthe alarm are stored in the controller's memory and may be viewedwithin the following alarm menus.ESuction Line = 15°CEvaporating pressureFLiquid Ln = 38°CCondensing pressure25AF25. # 2 Curr AlarmNoneLiquidLn = ##.# °CIn this menu are used to display any alarm condition which may bepresent in refrigerant circuit # 2. The temperature and pressurereadings at the time of the alarm will be stored in the controllersmemory and may be displayed for analisys from this menu.For an explanation of the alarm message displayed here refer tothe previous menu.26A26. # 1 Prev AlarmNoneThe alarm message for the last recorded Circuit 1 alarm may bedisplayed from this menu. This information will be replaced when acurrent alarm condition is cleared2727. # 2 Prev AlarmSee aboveANone

MicroTech130 C - 93/01 B - page 38Table 24ALR Compressors Number of fans "ON"unit size# 1# 2# 3# 4No Type D 1 2 3 D 1 2 3 D 1 2 3 D 1 2 3 total035÷055224fan stage 31 1 / / 1 1fan stage 2060-065Copeland3362 Discus 1 1 1 1 1 1fan stage 1070÷085095100110130 215518021022024026028531033536034McQuaysemihermetic• PWS• Double speed1111111111111114151313141415141414151415151511 11 2111 11 11 21 11 11 11 21 11 21 21 21111111111111114151314141515141415151515151511 11 211 11 11 21 21 11 11 21 21 21 21 21 21222111141616161414141511 11 21 21 21 11 11 21 2Condenser fanwired with thecompressor1111414151511 11 11 21 28106789101214151617181920Note: When Speedtrol is to be used, Speedtrol is applied to the fan which is energized when the compressor is turned onTEST PROCEDURE - TROUBLE ANALYSISAll of the following procedures assume that power isapplied to the MicroTech control panel and the circuitbreaker is on. Some of the following procedures requirethe removal or replacement of fuses, connectors,terminals or jumpers. Always shut off the power beforemaking the required changes.MICROPROCESSOR CONTROL BOARDThe MicroTech controller three LEDs which can be usedto diagnose some controller problems. Table 10 details tooperating condition indicated by these LEDs.If the microprocessor status LEDs do not follow the normalsequence as shown in Table 10, there is a problem with

MicroTech130 C - 93/01 B - page 39the controller.Likely problems include loss of controller power, corruptedsoftware or the controller itself may be defective.RED LED Remains On - This indicates that the MicroprocessorControl Board has failed the self-check andmust be replaced or the power supply voltage isabnormally low.RED LED Does Not Turn On - Check for 18 VAC betweenControl Board power supply input terminals 1 and 2. If 18VAC is present, check the fuses mounted adjacent to thepower connector. If this fuse is blown, it should bereplaced with a fuse of the same rating. If this fuse is notblown, it is likely that the controller is itself defective andmust be replaced.If 18 VAC is not present at the power connector, check for24 VAC at terminals 25 and 27. If 24 VAC is present here,Table 25 Controller status LED'sGreen led Red led IndicationOffOffOnOffOnOfftransformer T-4 is probably defective.No power to controllerSelf- test failureMicroprocessor operating normallyADI BOARDAll digital and analog input signals are conditioned by theADI Board. Power for the board is derived from theMicroprocessor Control Board via the interconnectingribbon cables. If the ADI Board appears inoperative, makesure these ribbon cables are fully seated in their socketsand the locking tabs are engaged.The digital unputs indicate the presence of 24 VAC byilluminating its corresponding LED. At 7.5 VAC to 24 VACthe digital input contacts are considered closed and theLED will be on. Below 7.5 VAC the contacts areconsidered open and the LED will be off. Individual digitalinputs may be tested by momentarily installing a jumperbetween terminal 25 and the ADI Board terminal to betested. If the input is operating properly, the LED willilluminate when 24 VAC from terminal 25 is applied. Referto drawing 716358D-01.Temperature sensors receive operating power from thenADI Board which relies on the Microprocessor ControlBoard's regulated 5 VDC power supply. If all temperaturesensors appear to have failed, check the 5 VDC supply onthe controller.KEYPAD/DISPLAYOperating power for the keypad/display is provided by theMicroprocessor Control Board via the interconnectingribbon cable. An inoperative keypad/display can be causedby a loose or damaged ribbon cable or the loss of thecontroller's power supply.Some production versions of the display are equipped witha contrast adjustment potentiometer which will blank thedisplay if set incorrectly. The optimum contrast setting maychange slightly based on ambient temperature. Adjust thiscontrol with a small screwdriver to achieve the bestdisplaycontrast.OPEN OR SHORTED TEMPERATURE SENSORSThe MicroTech Controller has a built-in function which willidentify a defective sensor. The two possible failure modesare indicated through the corresponding keypad menuitem as follow:"Open" = Open Sensor"Short" = Shorted SensorERRONEOUS PRESSURE READINGSIf the evaporator or condenser pressure readings, as readthrough the keypad, appear erroneous or unrealistic, thefollowing procedure is followed to check the pressuretransducers:1. Check for proper ribbon cable and other connections.2. Measure the voltage (0 to 5 VDC) across the suspectedpressure transducer (evaporator transducer 1 forexample) at ADI Board terminal A1.3. Compare this reading with what the value should beaccording to that shown in Figure 4. NOTE: The actualpressure to the transducer must be known. If thattransducer is not defective, then it is likely that ADI Boarditself is defective and must be replaced.OUTPUT BOARDSolid-state relays on the MicroTech Ccontroller OutputBoard all have contacts open when de-energized.However, because these relay are "solid-state", thecontacts are not "open" in the sense that electromechanicalrelays open their contacts. Instead, the relayswitches from low to high resistance.When checking the voltage in a circuit where these relayshave been incorporated, it is possible to be confused bythe presence of voltage on the load side of the relay. Ifthere is a load on the relay, the circuit will behave like atraditional relay circuit.That is, if the relay switches to "off", the voltage will drop tozero at the output of the relay. But, should the circuit be"open" between the relay output and the load, and theoutput relay is "off", the high resistance of the relay andthe voltmeter form a series circuit.

MicroTech130 C - 93/01 B - page 40McQuay monitor softwarepersonal computer specificationIBM PC or 100% compatible 386 minimum including:• 31/2" 1,44 MB floppy diskette driveUtilized for loading the MicroTech monitor program intothe hard disk of the computer. Also provides capability ofarchiving historical data and system back-up.• 2 MB RAM (Random Access Memory)The computer must have in order to run the MicroTechMonitor Program. Any memory resident programs thatrun in the background must be disabled.• Asyncronous Serial communications adapterA direct communications interface connection betweenthe PC and the MicroTch controller. Connection shouldbe 25 Pin Male or 9 Pin Male with a 9 to 25 conversioncable.• VGA Video Graphics AdapterFor high resolution graphics and data display.• Parallel Printer AdapterFor hard copy custom reports of all accumulated data.• Hard Disk Drive (20 MB min.)A mass data storage area for the operator interface,custom report software and essential data collection.• 101 Enhanced KeyboardRequired for more advanced functions of the operatorinterface and custom report software.• The computer shall include a DOS 5.0 and manualalong with other manuals provided with the computer.• The computer shall have internal timeclock that isbattery backed to mantain system time and date.• The computer shall come with the screen saver option,to extend the life of the display monitor.a Multisync or compatible VGA Color MonitorFor use with the video graphics adapter for highresolution data display.b Printer 192 CPS (Characteres per Second) Dot MatrixType Must have the ability of supporting IBM extendedcharacter graphics.c Printer cable, 6 Ft. ParallelFor communications connection between the PC andthe printer.The computer is used for changing setpoints, monitoringdata, trend logging, diagnostics, and remotely clearingalarms within the system.The computer is normally a dedicated personal computer,however, the operator may choose to exit the Monitorprogram from time to time to perform other functions suchas word processing or data manipulation using aspreadsheet program.It should be noted, however, that for maximumconvenience and functionality, the computer should beconsidered a dedicated computer for the MicroTechsystem.The communications from the unit control panel to thePersonal computer is shielded, twisted pair wire.The communications adheres to the industry standards ofRS - 232C and the rate of communications is 9600 baud.The recommended maximum distance from the personalcomputer to the control panel is 15 mt. If the requireddistance is in excess of 15 mt, an optional RS - 232extension kit is required (contact McQuay).Telephone line for remotemodem accessA voice quality, direct dial telephone line is required ifremote access and monitoring of the unit controller isdesired.The phone line should be terminated with a standardRJ-11 modular phone plug.

MicroTech130 C - 93/01 B - page 41Terms and definitionsASCII(American Standard Code for Information Interchange) Method with which all alphanumeric characters are assigned aunique number between 1 and 127.BaudNormally ranges from 300 to 9600 and indicates the speed of computer communication, the higher the BAUD, the fasterthe data transfer. The BAUD rate is changeable for each communications port.ChecksumThe operating system of the microprocessor, upon power up or a reset, sweeps through the application program memoryspace and adds the values of all memory locations together. The resultant number is referred to as the checksum and isused to insure that the application program space has not been corrupted.CPU(Central Processing Unit) The main component of the computer system. It interprets and executes program instructions,contains computational circuits, and input/output ports. Each MicroTech has its own CPU which allows it to operateindependently.DownloadThe act of sending information from a terminal to an MicroTech Controller: can be either individual setpoints or an entirenew logic program.EEPROM(Electronically Erasable Programmable Read Only Memory) Enables the MicroTech Controller to retain its memory evenduring power outages yet allow changing og values from a remote location.HexadecimalRefer to the base 16 number system in which the basic digits are represented by 0-9 and A-F:Decimal Hexadecimal Decimal Hexadecimal0-9 0-9 13D10A14E11B15F12C1610Computers operate in base 2 but since that quickly becomes complicated and it doesn't convert easily to decimal,hexadecimal is commonly used for computer applications.InputsThe MicroTech Controller allos up to 16 inputs from sensors that return a voltage of 0 TO 5 volts. Each reading isconverted to a number between 0 and 255. EXAMPLES: Temperature sensor, pressure transducer, potentiometer, etc.ModemDevice that allows communication with a controller network over a telephone line. Two modems are required, one at theterminal end of the phone line and one wired to a controller in the network.OutputThe MicroTech Controller allows up to 16 outputs capable of turning a device on or off.

MicroTech130 C - 93/01 B - page 42Parity CheckA check of whether the total number of 1's in a data byte is even or odd. Used in data transmission to insure error-freecommunication, data bytes are covered to either even or odd parity before transmission by setting their eighth bit.PortA communications channel on a controller for talking either to other controllers or to a terminal. Each unit has 2 ports forvarious network connections. Each port must be pre-set for specific communications purposes.Pressure TransducerDevice used to convert a reading of static pressure into a voltage for input into the MicroTech Controller.RAM(Random Access Memory) Computer memory that will NOT hold its contents through a power outage. The MicroTechController also contains some RAM for storage of temporary variables. RAM memory values may be changed an infinitenumber of times without any problem, whereas EEPROM's may only be overwritten approximately 10,000 times beforethey begin to fail.RS232CRefers to a hardware configuration standard used for communiations between computers and computer equipment.Many personal computers are equipped with RS232C connections and this is required for linking a PC with the controllernetwork.RS422/485Another hardware configuration that is very common for linking of computer equipment int network because of itsresistance to transmission errors at high BAUD rates. It involves the use of a twisted pair of wires to connect componentsand requires one controller to coordinate the communications between all other units.SetpointA desired value for some measured quantity. The MicroTech Controller operates to maintain comfort based upon thevalues of specific setpoints. Example: Leaving chilled water temperature, discharge air temperature, rom temperature,minimum and maximum CFM.TerminalNormally refers to a personal computer but could be any computer equipment capable of RS232C communications andASCII protocol. An IBM compatible personal computer is preferred.Temperature SensorThe room temperature is measured as output from a thermistor which the controller reads as a number between 0 and1024 and then calculates a Fahrenheit temperature.Timing ConstantsRefer to adjustable time values that the controller uses to manage its inputs and outputs. The time between roomtemperature readings or the amount of time to turn on an actuator are two examples. They may range from a tanth of asecond to 62 hours or they may also indicate ALWAYS and NEVER.UART(Universal Asynchronous Receiver-Transmitter) Tipically, a single computer chip that converts serial data transmissionsinto parallel information. The fact that the MicroTech Controller contains a UART means that it can transmit and receiveat different Baud rate. It also maintains automatic parity error checking and speeds the entire communications process.

NotesMicroTech130 C - 93/01 B - page 43

McQuay Italia S.p.A.Via Piani di S. Maria, 72S.S. Nettunense, km 12+30000040 Cecchina (Roma) ItaliaTel. : (06) 93 74 005Tlx. : 611349 MCQUAY IFax. : (06) 93 74 014We reserve the right to make changes in design and construction at any time, without notice.