Liebert Series 600T - Manual (Page 104)

98 Operation
Maintenance Bypass Load Transfers
To manually transfer the load between Maintenance Bypass and the UPS system bypass line, carefully follow
these instructions. Do not transfer the load between Maintenance Bypass and the UPS system (module inverters)
output. Use the SCC Monitor/Mimic Display screen to verify the UPS system bypass line is available.
If the load is on the UPS System Bypass:
a. Close the Maintenance Bypass Breaker (MBB).
b. Verify closure of the MBB. Then open the Maintenance Isolation Breaker (MIB). Load is now on
Maintenance Bypass.
c. If UPS bypass shutdown is required, open the Bypass Input Breaker (BIB).
If the load is on Maintenance Bypass:
a. Close the Bypass Input Breaker (BIB) or verify BIB is closed. Note that UPS System Bypass circuit
breaker (motorized) must also be closed.
b. Close the Maintenance Isolation Breaker (MIB).
c. Verify closure of the MIB. Then open the Maintenance Bypass Breaker (MBB). Load is now on UPS
System Bypass.
!
CAUTION
Make sure you understand the proper sequence before operating any circuit
breaker. Operating a Maintenance Bypass circuit breaker out of sequence could
cut off power to the critical load.