GE SG SERIES 10 Operating Manual

Contents

g GEOPM_SGS_USM_10K_40K_0US_V010.doc 12/88 Operating Manual SG Series 10, 20, 30 & 40 kVA3.2 OPERATION MODES3.2.1 Normal operation modeDuring normal operation, the Rectifierconverts input AC power to DC.The DC power provides input power for theInverter and charging power for the Battery.The Inverter converts the DC power tocontinuous and regulated AC power, whichsupplies the critical load.The control panel reports the Battery chargestatus and the expected backup time with theactual load. Fig. 3.2.1-1 Block diagram normal operation mode3.2.2 Utility failure operationWhen the Utility is no longer within acceptabletolerances, the Battery will provide the DCpower to the Inverter.The Inverter will maintain continuous ACpower to the Load until the Battery Voltagereaches the lower limit of the Inverteroperation capability.During the discharge, the LCD screen displaysthe estimated time the Battery can support thecritical load.Prior to the Battery completely discharging,the "stop operation" alarm (shutdownimminent) warns the operator that the Batteryis almost discharged and the UPS is about toshut down.Fig. 3.2.2-1 Block diagram Utility Failure operationIn case of parallel operationWith a parallel system for power capacity (see Section 3.3)• With the Bypass Utility power available, a low Battery warning on any unit will cause theLoad to be transferred to Utility (after a selectable time delay).• With Bypass Utility power not available, a low Battery warning on any unit will start the“stop operation” timer (adjustable).The Load will shut down at the end of the “stop operation” time period.With a parallel system for redundancy (see Section 3.3)• When a Battery low warning occurs on a unit not necessary to support the present load, thisunit will shut down after a timeout period (selectable).The Load is shared between the other units• As the warning occurs on one unit necessary to support the present load, the system startsthe "stop operation" timeout (selectable).The Load will shut down at the end of the “stop operation” time period.