Chapter 5 UPS Operation Instructions 47
Liebert
®
ITA 16kVA And 20kVA UPS User Manual
Chapter 5 UPS Operation Instructions
This chapter gives a detailed description of the UPS operation procedures.
During the operation, the buzzer alarm may appear, at this point, you can press the ALARM CLEAR button to silence
the audible alarm.
Warning: hazardous mains and/or battery voltage exists behind the protective cover
No user accessable parts are located behind the protective covers that require a tool for removal.
Only qualified service personnel are authorized to remove such covers.
If maintenance for rack is needed, notice that the neutral line is live.
5.1 UPS Start-Up
The start-up procedures can be performed after the installation is finished, the system has been commissioned by
authorized engineer and the external input MCBs are closed.
Warning
This procedure results in mains voltage being applied to the UPS output terminals. Confirm that the load power is safe, if there is a
load to be connected with the UPS output terminal. Ensure that the load is isolated with the UPS output terminal, if the load is not
ready for accepting the power.
The start-up mode of the single UPS includes normal mode start-up and battery mode start-up; refer to
2.6.3
Normal
Mode Start-Up
and
2.6.4 Battery Mode Start-Up
for details.
For the detailed information of the parallel UPS, refer to
3.5.3 Power-On Commissioning For Parallel System
.
5.2 Transfer Procedures Between Operation Modes
Note
The Inverter operation mode include Normal mode (mains inverter) and Battery module (battery inverter).
5.2.1 Transfer From Normal Mode To Battery Mode
In case of mains failure, the UPS will transfer to Battery mode. If you wish to transfer the UPS from Battery mode to
Normal mode, wait few seconds for mains input recovery. Ten seconds later, the rectifier will restart automatically, and
the inverter will restore the power.
5.2.2 Transfer From Inverter Mode To Bypass Mode
In Inverter mode, press the OFF button for two seconds, you can transfer the UPS to Bypass mode.
Note
In Bypass mode, the load accepts the power not from the pure power outputted by the inverter, but from the mains power directly.
For the detailed information of the Normal mode, Bypass mode, Battery and Maintenance Bypass mode, please refer
to
1.5 UPS State And Operation Mode
.
5.2.3 Transfer From Bypass Mode To Inverter Mode
In Bypass mode, press the ON button for two seconds. After the inverter runs in normal state, the UPS transfers to
Normal mode.
