Powerware 5075 kVA operation manual 164201261 Rev. F

•The START switch activates the power controls on the Control Panel. The START switch is center-biased (the key will rest only in the upright position). Its operation is similar to that of an automobile ignition switch. After setting the operator controls, you turn the START switch to the right momentarily to activate the controls. When you release it, it returns to the upright position.

The following paragraphs describe the controls and indicators found in the Environmental cabinet (see Figure 33).

•The circuit breaker (CB1) switch supplies power to the rectifier and inverter. If CB1 is on (closed), the rectifier turns on when the START switch is activated and the proper voltage is at the input terminals.

•The circuit breaker (CB2) switch controls the application of battery power to the UPS. If CB2 is closed, the rectifier charges the battery through the DC to DC converter during normal operation. If utility power is lost, battery power is supplied to the inverter through the DC to DC converter.

SMaintenance Bypass (MBP) Circuit Breaker --- This breaker is normally open. When closed, it feeds utility power to the critical load when the MIS breaker is opened.

SMaintenance Isolation (MIS) Circuit Breaker --- This circuit breaker is normally closed, feeding UPS power to the critical load. This breaker is opened to isolate the UPS after the MBP breaker is closed.

SBypass Input (BIB) Circuit Breaker --- This circuit breaker is normally closed feeding bypass power to the UPS internal bypass circuit. This breaker is opened to isolate the UPS bypass after the load is transferred to maintenance bypass.

Powerware BPIII Harsh Environment UPS 50--75 kVA Installation and Operation 65

164201261 Rev. F 111503