990-91079G-001

Isolate a Single UPS from the Parallel System

Use this procedure to shut down one UPS in a running parallel system.

NOTE: Before initiating this procedure, ensure that the remaining UPS units can supply the load.
  1. On the display select and then select confirm to power off the UPS.
  2. Turn the battery breaker(s) BB of the UPS to the OFF (open) position.
  3. Disconnect the battery relay from the display by selecting the battery symbol and selecting Batt relay control ON/OFF and confirm to turn off the battery relay. Verify that the Relay status is now off.
  4. Open external battery breaker if external batteries are connected.
  5. Turn the mains input breaker MIB of the UPS to the OFF (open) position.
  6. Turn the bypass input breaker BIB of the UPS to the OFF (open) position.
  7. Turn the external unit output breaker Ext. UOB of the UPS to the OFF (open) position.
  8. For the UPS with internal batteries, disconnect all batteries on the front of the UPS.
    DANGER
    hazard of electrical shock, explosion or arc flash
    • Wait at least 5 minutes before removing the cover of the UPS after the display has turned off to allow for the capacitors to fully discharged.
    • Always measure for hazardous voltages on all terminals before working on the UPS.
    Failure to follow these instructions will result in death or serious injury.
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