38 Chapter 5 Operating Instructions
Liebert APM 90 Integrated Modular UPS User Manual
5.2
UPS Start-Up Procedures
Before startup, the UPS must be fully installed and commissioned, and the external input switch must be
closed. Once those general conditions are met, the UPS may be started.
5.2.1
Start-Up Procedures (Into Normal Mode)
Warning
During these procedures the output terminals are live. If any load equipment is connected to the UPS output terminals,
please check with the load user and ascertain whether it is safe to apply power to the load. If the load is not ready to
receive power, open the corresponding output distribution switch.
The procedures for turning on the UPS from a fully powered down condition are as follows.
1. Close the UPS output switch and input switch in turn.
At this point, the LCD displays the start screen. The rectifier indicator flashes green while the rectifiers are
starting up. It stops flashing and becomes solid green about 30 seconds after the rectifiers enter normal
operation. After initialization, the bypass static switch closes. The states of the indicators are shown in
Table 5-1.
Table 5-1
Indicator state
Indicator
State
Rectifier indicator
Green
Battery indicator
Off
Bypass indicator
Green
Inverter indicator
Off
Load indicator
Green
Status indicator
Yellow
2. Press and hold the INVERTER ON key for two seconds.
Note
You must close the UPS output switch first, then close the input switch, and finally turn on the inverters. Otherwise, the
inverters will not start, and the UPS will generate Bypass STS fail alarm.
At this point, the inverters start and the inverter indicator flashes green. After the inverters enter normal
operation, the UPS transfers from the bypass to the inverters, the bypass indicator turns off, the inverter
indicator and load indicator turn on.
The UPS begins to operate in normal mode, and the states of the indicators are as shown in Table 5-2.
Table 5-2
Indicator state
Indicator
State
Rectifier indicator
Green
Battery indicator
Off
Bypass indicator
Off
Inverter indicator
Green
Load indicator
Green
Status indicator
Green