Powerware 9155 User Manual page 87

Powerware 9155 UPS (8–15 kVA) User's Guide
®
To switch the UPS to maintenance bypass from Normal mode
(UPS-mounted operation):
1. Turn the Maintenance Bypass switch through the SERVICE
position to the BYPASS position.
The battery circuit breaker trips, and the UPS is now bypassed,
with the load powered by utility power.
2. The UPS automatically shuts down.
To return to Normal mode from maintenance bypass (UPS-mounted
operation):
1. If an optional isolation transformer is installed, switch the input
circuit breaker to the ON position.
NOTE
The isolation transformer output is always 240V (180° phase
angle). Any equipment connected to the output requiring 208V (120° phase
angle) is at risk for damage.
2. Turn the Maintenance Bypass switch to the SERVICE position.
The UPS starts up in Bypass mode, with the load still powered
by utility power.
3. Switch the UPS battery circuit breaker to the ON position.
NOTE
Wait until the
Step 4; otherwise, power to the load may be lost.
4. Turn the Maintenance Bypass switch to the UPS position to
return to Normal mode. The UPS is now powering the load.
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indicator illuminates before proceeding to
UPS Maintenance
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