Emerson Liebert NX 50 and 60 Hz - Manual (Page 51)

Battery Installation
39
2.5 Battery Control
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
!
CAUTION
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).