PARALLEL BYPASS
To return to Normal mode from maintenance bypass:
1.Verify that all UPS breakers on the parallel tie cabinet are in the OFF position.
2.Switch on utility power where the UPSs are connected.
In a parallel capacity system (2+0 or 2+1), apply utility to the minimum number of UPSs required for capacity.
NOTE Use the same UPS that was used to set internal bypass to return the parallel system to Normal mode.
3.Set the system to internal Bypass mode:
S Using the button on the front panel display, scroll to the Control menu option and press the 
button.
SPress the 
button to select the Go to Bypass Mode option.
The 
and 
indicators illuminate, indicating the UPS system is operating in Bypass mode.
4.Switch all UPS breakers on the parallel tie cabinet to the ON position.
5.Switch the bypass breaker on the parallel tie cabinet to the OFF position.
6.On the same UPS front panel, set the UPS to Normal mode:
SPress the 
button to select the Go to Normal Mode option.
SEach UPS should go to Normal mode.
54 | EATON Powerware® 9155 Parallel UPS |