42 Chapter 5 Operating Instructions
Liebert APM 90 Integrated Modular UPS User Manual
Five seconds later, if all indicators illuminate green constantly, and then turns constant red, it indicates that all
indicators are normal.
4. Stop the test.
During system test, you can stop it be selecting the Stop testing option on the Command menu.
5.7
UPS Shutdown Procedures
5.7.1
Completely Powering Down The UPS
Caution
The following procedures will switch off all power to the load.
The following procedures are used to completely power down the UPS and load. All power switches, isolators
and circuit breakers will be open and the power will be removed from the load. In a parallel system, perform
each step of the procedures in every UPS module before proceeding to the next step.
1. Press the EPO switch on the UPS operator control and display panel. This disables the rectifier, inverter,
static transfer switch and battery operation, and the corresponding UPS is isolated from the load.
Note: Unless in an emergency situation, do not press the remote EPO switch.
2. Open the input switch and BCB.
All of the indicators and the LCD on the operator control and display panel will extinguish as the mains-driven
internal power supplies decay.
3. Open the output switch of the UPS.
Warning: hazardous battery voltage
After the UPS is powered down completely, the battery terminals still remain energized at hazardous voltage levels.
5.7.2
Completely Powering Down The UPS Whilst Maintaining The Power Supply To The Load
Caution
Ensure that the UPS has been installed with an external maintenance bypass cabinet before carrying out these
procedures.
The following procedures are applicable for completely powering down the UPS and still keeping the power
supply to the load.
1. Use the procedures in
5.3.4 Transfer From Normal Mode To Maintenance Mode
to transfer the UPS from
normal mode to maintenance mode.
2. Close the maintenance switch of the external maintenance bypass cabinet.
3. Open the input switch of the UPS.
4. Open the output switch of the UPS.
5.8
EPO Procedures
The EPO switch on the UPS operator control and display panel is designed to switch off the UPS in emergency
conditions, for example, fire, flood, and so on. The system will turn off the rectifiers, inverters and stop
powering the load immediately (including the inverters and bypass), and the battery stops charging or
discharging.