De-Energize The Liebert Nx 480 With Bypass Distribution Cabinet (Bdc); Energize Nx 480 With Bypass Distribution Cabinet (Bdc) - Liebert NX User Manual

11.5

De-Energize the Liebert Nx 480 with Bypass Distribution Cabinet (BDC)

To de-energize the Liebert NX 480V UPS w/ BDC:
1. On the Control Panel, press the INVERTER OFF button for 2 seconds.
2. Close CB3 Maintenance Bypass Breaker
3. Open CB5 Output Breaker
4. Manually open external battery breaker(s).
5. Open CB2 Bypass Input Breaker
6. Open CB1 Rectifier Input Breaker
7. Verify the indicator on the SKRU unit is illuminated
8. Press and hold the "Alarm Present Silence" button while rotating and removing the key.
9. Insert the key into the lock on the MBB and turn the key.
10. Close the MBB.
11. Verify the MBB is closed.
NOTICE
Risk of improper operation. Can cause property damage from loss of power to connected load.
Failure to close the MBB will interrupt power to the load. The load equipment is not protected
from normal supply aberrations when the Liebert NX is operating in the maintenance bypass
mode.
12. Open the MIB
13. Turn the key to complete the lockout of MIB
14. Remove Key from MIB lock.
15. Insert key into the SKRU lock unit and turn the key.
UPS is now isolated from the critical load.
16. Open CB3 Maintenance Bypass Breaker.
11.6

Energize Nx 480 with Bypass Distribution Cabinet (BDC)

To re-energize the partially de-energized Liebert NX 480V UPS with Liebert BDC:
NOTE
UPS system must be in bypass prior to the start of any transfers. Safety features prevent
transferring the load to bypass while the Liebert NX inverter is powering the load.
1. Verify the indicator on the SKRU unit is illuminated.
2. Press and hold the Alarm Present Silence button while rotating and removing the key.
3. Insert the key into the lock on the MIB and turn the key.
4. Close the MIB.
5. Verify that the MIB is closed.
NOTICE
Risk of power interruption. Can cause equipment damage.
Failure to close the MIB will interrupt power to the load.
6. Open the MBB.
7. Turn the key to complete locking out the MBB.
8. Remove the key from the MBB lock.
9. Insert the key into the SKRU lock unit and turn the key.
The UPS system is now available to be returned to normal operations.
10. Close the CB1 Rectifier Input Breaker.
11. Close the CB2 Bypass Input Breaker.
12. Verify that the Rectifier LED flashes green, then turns solid green after about 30 seconds.
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Operating Instructions
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Liebert NX