User`s guide

Eaton 9355 Parallel UPS (10/15 kVA) User's Guide S 164201601 Rev B www.eaton.com/powerquality

Chapter 10 Parallel Bypass

To switch the parallel UPS to maintenance bypass from Normal mode:

1. From any UPS, 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.

S Press the button to select the Go to Bypass Mode option.

The

indicator illuminates and the indicator extinguishes,

indicating the UPS system is operating in Bypass mode.

2. Switch the bypass breaker (may be designated MBP or CBP) in the

parallel tie cabinet to the ON position.

3. If present, switch the maintenance isolation breaker (MIS) on the

parallel tie cabinet to the OFF position; otherwise, switch the UPS

breakers (may be designated MOB or UPS) on the parallel tie

cabinet to the OFF position.

To return to Normal mode from maintenance bypass:

1. Verify that the maintenance isolation breaker (if present) on the Tie

Cabinet is in the OFF position or all of the UPS breakers are in the

OFF position.

2. Switch on utility power where the UPSs are connected.

In a parallel capacity system (N+0 or N+1), apply utility to the

minimum number of UPSs required for capacity.

The

indicator illuminates, indicating the UPS system is

operating in Bypass mode.

The display indicates On Manual/Maintenance Bypass.

3. Verify voltage is present on the UPS output by checking that an

output voltage reading present on the front panel LCD display.