Emerson Liebert NX 480V - Manual (Page 87)

Operating Instructions
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9.8.3 Shutdown Procedure—Complete UPS and Load Shutdown
This procedure must be followed to completely power down the UPS and the load. All power switches,
isolators and circuit breakers will be opened and power will be removed from the load.
In multi-module systems, perform each step of the procedure in every UPS module before proceeding
to the next step.
1. Press the EPO (Emergency Power Off) button at the UPS front panel only. This will disable
Rectifier, Inverter, Static Switch and Battery operation. The load will be de-energized.
2. Open the UPS door to gain access to the main circuit breakers.
3. Open the Rectifier input circuit breaker CB1.
4. Open external battery circuit breaker. This breaker is inside the battery cabinet or is otherwise
adjacent to the battery racks.
5. Open Output circuit breaker CB5.
6. Open bypass input circuit breaker CB2.
7. Ensure maintenance bypass circuit breaker CB3 is open.
8. All mimic panel LED indications and messages will extinguish as the mains-driven, internal
power supplies decay.
9. To completely isolate the UPS from the AC supplies, the main external power input isolator (both
isolators, where dual supplies are provided for rectifier and bypass) and external output isolator
must be opened and tagged with warning labels accordingly.
9.9 Commissioning a Parallel System
Check the input and output wiring of each UPS module. Ensure that the phase rotation sequence of
the main inputs and the bypass inputs and outputs of each UPS module are the same. Ensure that
the parallel cables are connected firmly.
It is assumed that the installation is complete, the system has been commissioned by authorized per-
sonnel and the external power isolators are closed. Disconnect the load before startup.
!
CAUTION
This procedure will shut off power to the load.
NOTE
Before beginning this procedure, shut down the connected load to prevent the possibility of
damage.
!
CAUTION
Except in an emergency situation, do not press any remote EPO button
!
CAUTION
The operations described in this section must be performed by authorized electricians or
qualified technical personnel. If you have any difficulty, call 1-800-LIEBERT for assistance.