Vertiv Liebert EXM - 6.5.3 Switching Between UPS Operation Modes; 6.6 Switching the UPS from Normal Operation to Maintenance Bypass

Vertiv™ | Liebert® EXM
™
50-250kVA, 480V, 60Hz User Manual | 60
6.5.3 Switching Between UPS Operation Modes
To switch from Normal Mode to Static Bypass Mode
1. Log in as Operator, Administrator or Service.
2. Touch the OPERATE tab.
3. Touch Inverter Off radio button to switch to Bypass Mode
4. To continue, confirm turning Off the inverter when prompted.
To Switch From Bypass Mode To Normal Mode
1. Log in as Operator, Administrator or Service.
2. Touch the OPERATE tab.
3. Touch Inverter On radio button.
To continue, confirm turning On the inverter when prompted.
6.6 Switching the UPS from Normal Operation to Maintenance Bypass
Follow the procedure below to transfer the load from the UPS inverter output to the Maintenance
Bypass system.
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.
This procedure assumes that UPS is operating normally.
1. Log in as Operator, Administrator or Service.
2. Touch the OPERATE tab.
3. Touch the Inverter Off radio button.
4. To continue, confirm turning Off the inverter when prompted.
5. Open the Liebert
®
MBC
™
door to gain access to the bypass isolation breaker (BIB), maintenance bypass
breaker (MBB) and maintenance isolation breaker (MIB).
6. 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).
7. Insert the Key into the lock on the MBB and turn the Key.
8. Close the MBB.
9. Verify the MBB is closed. Failure to close the MBB will interrupt power to the load.
10. Open the MIB.
11. Remove the key from the lock on the MIB. Insert the key into the lock (K0) and turn the key.
12. The UPS system is now isolated from the critical load.
13. For a single-input system, the bypass isolation breaker (BIB) remains closed; this allows power to remain
present at the UPS input; refer to Figure 33.
NOTE
In Static Bypass Mode, the load is being powered by the utility and is not protected from
fluctuations in input power: spikes, sags and failure.
NOTE
Pressing Silence from the OPERATE tab cancels the audible alarm, but leaves the warning
message displayed until the appropriate condition is rectified.