Chapter 5 UPS Operation Instructions 43
Liebert
®
ITA 10kVA UPS User Manual
5.7.4 Transferring UPS To Battery Mode From Mains Failure
In the event of mains failure, the UPS will transfer to Battery mode. The UPS will turn off automatically if it works until
the battery power is depleted. When the mains restores, the UPS will turn on automatically, and enter Normal mode.
This function is designed for unattended operation. If the UPS is turned off manually when it is working in Battery
mode, then it needs to be turned on manually after the mains restores, and it cannot turn on automatically.
5.7.5 Transferring UPS To Bypass Mode From Inner Overheating Protection
Too high ambient temperature or poor ventilation of the UPS may result in the high temperature in the UPS. At this
moment, the UPS output will transfer to Bypass mode, the fault indicator will on, indicator 3 will blink (see Figure 4-1
for the position), and the UPS will beep for a long time. At this moment, you should cut off the UPS input power
supply, remove the obstacles in the air channel, or increase the clearance between the UPS and the wall. After the
USP is cooled, connect the UPS to the mains again and restart it.
5.7.6 Transferring UPS Fault State Upon Output Short Protection
If the UPS load is shorted, the UPS output will be cut off, the fault indicator will be on, the yellow indicator of the load
indicator will blink, and the UPS will beep for a long time. At this moment, you should disconnect the short connected
load from the UPS, cut off the input power and wait for ten minutes until the UPS turns off automatically (or turn off
the UPS by pressing the OFF key manually after 10 seconds). After the short circuit fault is eliminated, connect the
UPS to the mains again and restart it.
5.7.7 Transferring UPS To Maintenance Bypass Mode From Inverter Mode
When the UPS is operating in Inverter Output mode, follow the procedures below to transfer the load to Maintenance
Bypass mode from Inverter Output mode.
警告
危 险
Note
1. Before conducting the transfer, first ensure that the bypass is normal and synchronizes with the inverter. Failure to meet above
requirements may cause power supply interruption of the load in short time.
2. To realize this function, you need to select a POD or configure a maintenance bypass MCB by yourself.
1. Press and hold the OFF key for one second.
The inverter indicator turns off, the buzzer beeps. The load transfers to static bypass, and the inverter turns off.
2. Close the maintenance bypass MCB on the front panel of the POD, the load power is supplied by the maintenance
bypass.
警告
危 险
Warning
If you need to maintain the UPS, wait for about 10 minutes until the capacitance and voltage of the internal DC bus finish
discharging.
3. Open the input MCB and output MCB of the UPS.
5.7.8 Transferring UPS To Inverter Mode From Maintenance Bypass Mode
After the UPS maintenance is finished, follow the procedures below to transfer the load to Inverter mode from
Maintenance Bypass mode.
警告
危 险
Warning
Because no auxiliary contact information of the maintenance bypass MCB is imported to the UPS, the UPS operation restoration
after maintenance must be carried out strictly in accordance with the procedures below, otherwise the equipment may be
damaged.
1. Close the output MCB on the front panel of the POD.
2. Close the main input MCB and bypass input MCB on the front panel of the POD.
