Vertiv Liebert EXM - 6.7 Switching the UPS from Maintenance Bypass to Normal Operation

Vertiv™ | Liebert® EXM
™
50-250kVA, 480V, 60Hz User Manual | 63
6.7 Switching the UPS from Maintenance Bypass to Normal Operation
Follow the procedure below to transfer the load from the Maintenance Bypass system to the UPS
inverter output.
These conditions must be met for this operation to proceed:
• the UPS must be operating normally
• the BIB breaker must be closed
• the UPS system must be in the Maintenance Bypass mode of operation.
NOTICE
Risk of loss of power to the connected load. Can cause equipment damage.
This procedure must be performed by properly trained and qualified personnel who are knowledgeable
about the operation of this system. Failure to follow these instructions will result in loss of power and
possible damage to critical equipment.
Before performing this operation, read any messages on the touchscreen to be sure that bypass supply is
regular and the inverter is synchronous with it. If those conditions are not present, there is a risk of a short
interruption in powering the load.
1. Verify that the Liebert
®
EXM
™
is in Maintenance Bypass Mode.
2. Open the Liebert
®
MBC
™
door to gain access to the bypass isolation breaker (BIB), maintenance bypass
breaker (MBB) and the maintenance isolation breaker (MIB).
3. When the Lamp indicator on the Liebert
®
MBC
™
is illuminated, press and hold the adjacent push button
and remove the key from the lock (K0).
4. Insert the key into the lock on the MIB, and turn the key.
5. Close the MIB.
6. Verify the MIB is closed. Failure to close the MIB will interrupt power to the load.
7. Open MBB.
8. Remove the key from the lock on the MBB.
9. Insert the key into the lock (K0) and turn the key.
The UPS system is now supplying power to the critical load.
10. Log in as Operator, Administrator or Service.
11. Touch the OPERATE tab.
12. Touch the Inverter On radio button.
13. To continue, confirm turning On the inverter when prompted.
NOTE
Pressing the Alarm Silence Switch cancels the audible alarm, but leaves the warning message
displayed until the appropriate condition is rectified.