Emerson 400V Manuel D’Utilisation

The battery circuit breaker is controlled by the battery circuit breaker controller board, which is 

located within the battery cabinet or adjacent to the battery circuit breaker when the batteries are 

rack-mounted. This board controls the circuit breaker's undervolt release coil and also provides a path 

for the circuit breaker auxiliary contacts to signal the circuit breaker status back to the UPS control 

logic. Refer to Figure 25. All connections between the controller board and the UPS unit are made 

via auxiliary terminal Block X3 BCB of the Monitor Board, which is located at the rear of the door in 

the UPS Cabinet (refer to 1.8.3 - External Circuit-Breaker Interface).
Battery temperature sensor cables are connected between UPS auxiliary terminal block X3 BCB, the 

Battery Circuit Breaker controller board and the battery as shown in Figures 25 and 26.
Cables connected to X3 BCB must contain a protective earth wire or a shield, be segregated from 

power circuits, double insulated and of a typical 0.5 to 1mm

2

 cross-section area for maximum runs 

between 25 and 50 meters respectively. The shield should be connected to the protective earth of the 

battery cabinet or battery breaker, not at the UPS

UPS containing an internal automatic battery contactor do not require BCB board, nor 

undervoltage control of the BCB. 
In this case, direct wiring to the NX Monitor Board is required:
• the auxiliary NO contact of the battery circuit breaker is wired directly to the NX monitor 

board terminal X3 BCB: 2-3.

• “On-Line” X3 BCB terminals 4-3 of the NX monitor board are linked. 
• Any temperature sensor is wired directly to the NX monitor board terminal X7: 

2(+12V),3(signal),4(GND). 

For details, refer to 1.7 - Control Cables and Communication
The above applies to:
• 30 to 40kVA models with internal battery
• - any model with the Battery Start option
• The commissioning engineer must program the UPS accordingly (e.g., enable or disable bat-

tery temperature compensation, enable internal battery contactor).