PowerWalker VFI 20000-40000TAP 3/3 BI, User Manual

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6.4.7 UPS and Critical Load Shutdown
To perform maintenance or service on the critical load, shut down power to the load:
1. Turn off all equipment that is being powered by the UPS parallel system.
2. Transfer the UPSs to bypass by performing the procedure in paragraph 6.4.3.
3. Perform the LOAD OFF procedure in paragraph 6.4.10.
The output and bypass backfeed contactors open, and the power module is turned off.
5. Open all input switches.
6. Open all of the maintenance bypass switches.
7. Open the output switch.
8. Open all of the MOBs.
9. Open all of the UPSs input and bypass feeder circuit breakers.
10. Open all external battery breakers
4. Perform the battery charger off procedure in paragraph 6.4.8 for each UPS.
The input and battery relay open.
WARNING
Power is present inside the UPS cabinets after the upstream input feeder circuit breakers are
opened because of the installed external battery cabinet.
6.4.8 Charger Control
To turn an individual UPS battery charger on:
1. Select the CONTROLS symbol on the main menu bar on the UPS requiring the charger to be turned on. The
System Control screen is displayed.
2. Select Battery on the System Control screen
3. On the Battery System Control screen, select the RESTING CHARGING command, then press the
RETURN pushbutton.
To turn an individual UPS battery charger off:
1. Select the CONTROLS symbol on the main menu bar on the UPS requiring the charger to be turned off. The
System Control screen is displayed.
2. Select Battery on the System Control screen.
3. On the Battery System Control screen, select the CHARGING RESTING command, then press the
RETURN pushbutton.