Operation 105
3.4.4 Automatic Module Off-Line
Forspecified UPS module faults, the control logic willinitiate an automatic isolation and shutdown ofthe UPS
module.In the Module Off-Line mode the output, battery(MBD), and input circuit breakers are open. If the UPS
systemwas operating in the redundant mode when the module was taken off-line,the critical load will remain on
theUPS system. If the UPS system was operating in the non-redundant mode,an automatic transfer to bypass
willbe initiated. Note that the bypass lineis usually not available during Low BatteryS hutdown.One Module
Off-Lineis illustrated in Figure 52.
Thefollowing UPS module faults will initiate an automaticModule Off-Line:
DCOver-Voltage Shutdown
HardwareShutdown
InverterFault
Low-BatteryShutdown
OverloadShutdown
Over-TemperatureTimeout
Rectifier Fuse Blow n
ReversePower
Refer to Tabl e 1 for more informationregarding these alarm messages.
3.4.5 Automatic Emergency Modules Off
Forthe specified UPS system fault, thec ontrollogic will initiate an automatictransfer to bypass followed imme-
diatelyby a shutdown and isolation of the UPS system. In the EmergencyModules Off mode the output, battery
(MBD),and input circuit breakers at each UPS module are open. The System Bypass Breaker(SBB) will be
closed if the bypass line is ava ilable. Emergency Modules Offis illustrated in Figure 54.
Thefollowing UPS system fault will initiate an automaticEmergency Modules Off:
OutputOver Voltage
Refer to Tabl e 1 for more informationregarding alarm messages.
Yourinstallation may include a Remote EmergencyPower Off mode that can be initiated automatically by a
contactclosure in the critical load equipment. Refer to 3.2.8 - EmergencyP ower Off.
NOTE
Aload transfer to the bypass line will be completed whenever an automatictransfer
tobypass is initiated and the bypass line is available. If the OK to Transfer condition
ispresent, the load transfer will be uninterrupted.If the Static Switch Unable alarm
messageis present for any reason,the automatic transfer will be interrupted for40 to
120milliseconds. Because of the reliabilityof the UPS components, an interrupted
loadtransfer is a very unlikely occurrence.
DISCONTINUED
PROD U C T