Chapter 4 UPS Operation Instructions 33
Liebert ITA 16kVA/20kVA User Manual
4.2.2 Transferring From Normal Mode To Bypass Mode
In Normal mode, press the OFF for 2 seconds, you can switch the UPS to Bypass mode.
Note
In Bypass mode, the load accepts the power not from the pure power output by the inverter, but from the mains directly.
4.2.3 Transferring From Bypass Mode To Normal Mode
In Bypass mode, press the ON button for 2 seconds. After the inverter runs in normal state, the UPS switches to
Normal mode.
4.2.4 Transferring From Normal Mode To Maintenance Bypass Mode
When the UPS is running in Normal mode, you can use this procedure to make the load switch from inverter output to
maintenance bypass.
Caution
1. Before performing this procedure, you should check the LED information first, and make sure the bypass is normal and
synchronizes with the inverter. Otherwise, it may result in the load power supply interruption for a while.
2. You should select the single POD options or prepare the maintenance bypass switch by yourself, so as to realize this function.
1. Press the OFF for 2 seconds.
The inverter indicators are off, and the buzzer alarms. The load switches to the static bypass, and the inverter shuts
down.
Note
Press the ALARM CLEAR button can silence the alarm, but the alarm message of the the LCD is not disappeared until the alarm
status is cleared.
2. Close the maintenance bypass switch on the single POD front panel, and the maintenance bypass can supply
power to the load.
Warning
If you wish to maintain the UPS, you should wait 10 minutes for the internal DC bus capacitance voltage discharging.
3. Disconnect the main/bypass input/output switches.
Caution
1. When the UPS is in Maintenance Bypass mode, the load does not have the mains abnormal protection.
2. After the UPS switches to maintenance bypass, the UPS is not in operation, and the LCD is no display, and only the user
terminal block of the single POD is electrified. Be careful when removes the UPS to be maintained.
4.3 Complete Shutdown Procedure
If you wish to shut down the UPS completely, the procedures in
4.2.4 Transferring From Normal Mode To
Maintenance Bypass
Mode
should be followed, so as to transfer the UPS from Normal mode to Maintenance Bypass
mode.
Disconnect the external input switch, if you wish to isolate the UPS from AC power.
