15
Instruction Book
IB182923EN September 2018 www.eaton.com
AMH-4.76-VR
+
VR-Series
+
Replacement Circuit Breaker
4.7.3 ACTIVE INTERLOCK
The active interlock keeps the breaker from closing until the primary
disconnects are adequately engaged. Adjustment of the interlock
is factory set and should not be tampered with. The location of the
breaker’s active interlock can be seen in Figure Set 3.3. The interlock
components of the switchgear should closely resemble Figure 5.3.b.
The breaker’s active interlock roller interfaces with the switchgear’s
active interlock cam. The active interlock is activated by the elevating/
lowering motion of the breaker as well as movement of the clutch
handle linkage assembly. An attempt to close a charged breaker
between ‘Disconnect / Test’ and the connected position will result in
a trip-free operation. An attempt to rack a closed breaker will result
in opening of the main contacts but will not cause charged closing
springs to discharge.
m
WARNING
IF THE ACTIVE INTERLOCK FAILS TO OPERATE AS DEFINED IN THE ABOVE
SECTION, CONTACT AN EATON REPRESENTATIVE IMMEDIATELY.
4.7.4 SHUTTER INTERLOCK
Each GE AMH-4.76 circuit breaker compartment is equipped with
a shutter to shield the high voltage stabs in the cubicle when the
breaker is not in the cubicle. The shutter is regulated by the circuit
breaker shutter actuator that opens the shutter as the circuit
breaker is racked into the circuit breaker compartment and closes
the shutter as the circuit breaker is racked out of the circuit breaker
compartment.
m
DANGER
DO NOT FORCE THE CIRCUIT BREAKER INTO THE CIRCUIT BREAKER
COMPARTMENT. DOING SO MAY DAMAGE PARTS THEREBY RISKING
DEATH, PERSONAL INJURY, AND/OR PROPERTY DAMAGE.
4.8 MISCELLANEOUS ITEMS
4.8.1 OPERATIONS COUNTER
All AMH-VR
+
circuit breakers are equipped with a mechanical
operations counter (Figure Set 3.3). As the circuit breaker opens,
the linkage connected to the pole shaft lever advances the counter
reading by one.
4.8.2 MOC OPERATOR
The MOC switch is external to the circuit breaker and mounted
within the confines of the switchgear cubicle. The breaker’s MOC
operator interfaces with the cell MOC switch in the same manner
as the original breaker being replaced. All VR-Series breakers, which
are supplied with MOC operators, are engineered with
SURE CLOSE
Technology. This technology decouples the MOC operator from the
main breaker operating mechanism. This prevents the MOC switch
from stalling the circuit breaker during a closing operation, preventing
damage to the cell MOC components, and extends the life of the
MOC switch.
m
WARNING
EXTREME CARE SHOULD BE TAKEN TO AVOID PERSONNEL OR EQUIPMENT
CONTACT WITH THE MOC SYSTEM WHEN OPERATING THE BREAKER DUE
TO THE ASSOCIATED MECHANICAL FORCE. CONTACT WITH THE MOC
OPERATOR DURING OPERATION COULD RESULT IN INJURY.