Using The Ups Load Off Pushbutton - Powerware 9390 Installation & Operation Manual

10.2.8 Using the UPS LOAD OFF Pushbutton

A UPS Load Off is initiated by the LOAD OFF pushbutton from the main menu bar or the
System Controls menu bar. This pushbutton can be pressed to control the UPS output. The
UPS LOAD OFF pushbutton de-energizes the critical load and powers down the UPS.
The UPS (including Bypass) remains off until restarted.
To use the LOAD OFF pushbutton:
Powerware 9390 UPS (40–80 kVA) Installation and Operation Manual S 164201535 Rev C
®
The input, output, and bypass backfeed contactors open, the battery breaker or
disconnect is tripped, and the power module is turned off immediately, without
asking for verification.
8. Open all UPM input and bypass (if dual feed) feeder circuit breakers.
The parallel system and Load is now de-energized.
9. To restart the parallel system after using the REPO pushbutton, reset the REPO
switch and then follow the procedure in paragraph 10.2.1 or 10.2.2.
NOTE The UPM LOAD OFF pushbutton controls only the UPM on which Load Off was
activated and only interrupts the ability of that module to deliver power to the critical
bus. The redundant modules continue to support the critical load. The UPM can be shut
down only if the remaining UPMs can support the critical load without being
overloaded. To remove all power from the critical load, use the REPO pushbutton.
1. Press the LOAD OFF pushbutton.
The Load Off screen appears, providing a choice to proceed or abort the
shutdown.
All power to the critical load is lost when the 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 from the Load Off menu bar, and hold for
three seconds. To abort the shutdown, press CANCEL.
When LOAD OFF is selected and held for three seconds, the input, output, and
bypass backfeed contactors open, the battery breaker or disconnect is tripped,
and the power module is turned off.
Do not attempt to restart the system after Load Off until the cause of the shutdown has been
identified and cleared.
3. To restart the UPS after pressing the LOAD OFF pushbutton, follow the procedure,
in paragraphs 10.2.1 or 10.2.2.
UPS Operating Instructions
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C A U T I O N
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