Chapter 5 Ups Operation Instructions; Ups Start-Up; Transfer Procedures Between Operation Modes; Transfer From Normal Mode To Battery Mode - Liebert NXC User Manual

UPS Operation Instructions
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.
No customer operation parts are located behind the protective covers that require a tool for removal.
Only qualified service personnel are authorized to remove such covers.
If the 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.
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 2.5.3 and 2.5.4 for
details.
For the detailed information of the parallel UPS, refer to 3.4.3.

5.2 Transfer Procedures Between Operation Modes

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 the event of mains failure, the UPS will transfer to Battery mode. If you wish to transfer the UPS from Battery mode to Normal
mode, you should wait few seconds for mains input recovery. 10 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 2 seconds, you can transfer the UPS to Bypass mode.
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.

5.2.3 Transfer From Bypass Mode To Inverter Mode

In Bypass mode, press the ON button for 2 seconds. After the inverter runs in normal state, the UPS transfers to Normal mode.

5.2.4 Transfer From Inverter Mode To Maintenance Bypass Mode

When the UPS is running in Normal mode, you can use this procedure to make the load transfer from inverter output to
maintenance bypass.
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Warning: hazardous mains and/or battery voltage exists behind the protective cover
Warning
Note
Note
User Manual 10H52188UM51 - Rev. 1 - 09/2011
Liebert NXC