Operation Manual - ASSMANN IT-Solutions AG

3.4 Automatic Bypass SwitchIf the output converter is unable to deliver the demanded output power because of overload or overtemperature,the automatic bypass switch will automatically transfer the load to the utility. When the situation is corrected theUPS will switch back to normal operation, i.e. the load is transferred back to the output converter. Though theautomatic bypass switch is shown as a simple mechanical switch in figures 2-5, the transfers are done bymeans of thyristors, i.e. electronically, without any interruption of the power supplied to the load.In case of a severe overload or short-circuit the magnetic bypass circuit breaker (rear panel) may trip in order toprotect the UPS. If the current is insufficiently high to trip the breaker, the UPS will be switched off by thesoftware in order to protect the UPS and connected equipment.MANUAL BYPASS SWITCH1-PHASEMAINS INPUTBYPASSFILTERRFIFILTERTO LOADRFIFILTERINPUTCONVERTER/BATTERYCHARGEROUTPUTCONVERTERAUTOMATICBYPASSSWITCHOPTIONSLOTS FOR:RPA CARDSNMP CARDOPTIONALRELAY CARDBATTERYEXTENSIONBATTERYMICROPROCESSOR CONTROLSYSTEMON/OFFFRONTPANELSTANDARDINSTALLED:RS232/CONTACTINTERFACEFigure 4. Bypass operation: automatic bypassIf a power failure occurs during bypass operation, load power is lost. If the UPS functions under overloadconditions it may not be able to protect the load.3.5 Manual Bypass Switch (Service switch)The system can be bypassed manually using the manual bypass switch located at the rear panel. It is a twopositionswitch: the normal position is '1': as in figures 2-4. Position '2' is the service position: the load is directlyconnected to the utility input. This way maintenance of the UPS (e.g. battery replacement, as in fig. 5) ispossible without interruption of the power supplied to the load.CAUTION: REFER SERVICE TO QUALIFIED PERSONNEL ONLY.MANUAL BYPASS SWITCH1-PHASEMAINS INPUTBYPASSFILTERRFIFILTERTO LOADRFIFILTERINPUTCONVERTER/BATTERYCHARGEROUTPUTCONVERTERAUTOMATICBYPASSSWITCHOPTIONSLOTS FOR:RPA CARDSNMP CARDOPTIONALRELAY CARDBATTERYEXTENSIONMICROPROCESSOR CONTROLSYSTEMON/OFFFRONTPANELSTANDARDINSTALLED:RS232/CONTACTINTERFACEFigure 5. Bypass operation: manual bypassOPM_LPE_11X_3K0_10K_1GB_V041 7 GE DE LP 11 UPS: User manual 4.1 (GB)