Emerson 250-400kVA Manuel D’Utilisation

Changing the load from the UPS system to the UPS bypass is called a transfer. Changing the load 

from UPS bypass to the UPS system is called a retransfer. Note that the UPS system control logic can 

initiate automatic load transfers and retransfers. Refer to 2.6 - Automatic Operations.

1. Press the “Transfer” menu button on the touchscreen.
2. The Transfer/Retransfer screen will appear in the multipurpose window (see Figure 18).
3. If the UPS output is with synchronization with the bypass, press the “Bypass” button. This will 

transfer the load from UPS to Bypass.

1. Press the “Transfer” menu button on the touchscreen.
2. The Transfer/Retransfer screen will appear in the multipurpose window (see Figure 18).
3. If the UPS output is with synchronization with the bypass, press the “UPS” button. This will 

transfer the load from Bypass to UPS.

To manually transfer the load between Maintenance Bypass and the UPS bypass line, carefully follow 

these instructions. Do not transfer the load between Maintenance Bypass and the UPS module 

(inverter) output. Use the Monitor/Mimic Display screen to verify the UPS bypass line is available.

Risk of equipment damage. Failing to follow the proper operating sequence when operating 

any circuit breaker may cause damage to the connected equipment. Operating a Maintenance 

Bypass circuit breaker out of sequence could cut off power to the critical load.

Battery 

System

DC Bus

BFB

CB2

CB1

MBD

MBB

MI

B

MBFB

BIB

RIB

UPS Module

Two Breaker Maintenance Bypass Cabinet

Main Input 

Switchgear

Critical 

Load