Lucent Technologies Lineage
®
2000 ECS Battery Plant J855003D-3
Issue 5 January 1999
Maintenance 5 - 5
Load Circuit
Breaker
Replacement
STEP A: Obtain a replacement circuit breaker. See below,
“Spare Parts.”
STEP B: Verify that the faulty breaker is in the OFF position.
STEP C: Loosen the 1/4 turn fasteners and open the dc
distribution cover.
STEP D: Measure the voltage on terminal block TB701 at the
load connection associated with the faulty breaker, to verify that
the breaker is truly open. The voltage on TB701 relative to the
battery bus bars or circuit breaker bus bar should be
approximately the float voltage of the plant.
If the faulty breaker is, in fact, still closed, the load equipment
which it powers must be shut down so that no current flows
through the breaker.
DANGER:
Do not attempt to unplug a circuit breaker which may be
carrying current. Arcing may result in personnel injury and
equipment damage.
STEP E: Unplug the faulty breaker from the printed wiring
board.
STEP F: Switch the new circuit breaker to the OFF position
before plugging it in.
STEP G: Plug in the new breaker, ensuring that line, load and
alarm connectors are properly mated (see Figure 2-4).
STEP H: For safety, close the dc distribution door before
proceeding to the next step.
WARNING:
Before applying power to any individual load,follow the
powering up instructions as provided in the associated load
equipment documentation.
STEP I: Turn on the load circuit breaker. If the circuit breaker
trips immediately when turned on, this may be due to inrush
current and does not necessarily indicate a fault condition.
Attempt to close the circuit breaker a second time. If the breaker
trips again, check the wiring to the load circuit.
