Ups System And Critical Load Shutdown; De-Energizing The Critical Load - Eaton 93PM User And Installation Manual

6.4.7 UPS system and critical load shutdown

To perform maintenance or service on the critical load, shut down power to the load by performing
the following procedure:
1. Turn off all equipment that is being powered by the UPS system.
2.
Perform the LOAD OFF procedure (see Chapter 6.4.8 De-energizing the Critical Load on
page 66). The input, output, and bypass backfeed contactors open, the battery breaker or
disconnect is tripped, and the power module is turned off.
Power is present inside the UPS cabinet until the upstream input feeder circuit breaker is
opened.
3. Unfasten the front door latch and swing the door open.
4. Open the rectifier input switches if included in the UPS system, and verify that battery breaker
is open, and close the front door.
5. Open the UPS input and bypass feeder circuit breakers.
6. Repeat steps 3-5 for all UPSs in the system.

6.4.8 De-energizing the Critical Load

A UPS system Load Off is initiated by the Load Off button from Controls > System Controls screen. This
button can be pressed to control the UPS output. The Load Off button de-energizes the critical load and
powers down the UPS system.
The UPS system (including Bypass) remains off until restarted.
1. Press Load Off.
The shut down screen appears, providing a choice to proceed or abort the shutdown.
All power to the critical load is lost when Load Off is selected in the following step. You
should use this feature only when you want to de-energize the critical load.
2. To shut down the UPS, press Load Off. To abort the shutdown, press ABORT. When Load Off
is selected, the input, output, and bypass backfeed contactors open, the battery breaker or
disconnect is tripped, and all the UPSs in the system are turned off.
Do not attempt to restart the system after Load Off until the cause of the shutdown has
been identified and cleared.
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User's and Installation Guide
30-200 kW P-164000249
Revision 2