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54
Operation
Power/Vac® Metal-Clad Switchgear 5kV & 15kV
01.4IB.67000
the metal-clad switchgear, one member is
stationary and the other is a spring loaded slide
attached to the racking mechanism. A third
member, a notched sliding link, provides the
key lock functions and is described under Key
Locks (Figure 41).
To test the function of the negative interlock,
install a circuit breaker following the
instructions given in Ch 5 Operation, B. Inserting
the Removable Element Into the Compartment.
For this test the control power circuits in the
metal-clad switchgear must be energized.
Place the breaker in the “Disconnect/Test”
position and connect the secondary disconnect
device by pulling down on the breaker handle
and inserting the level arm fully into the
breaker. This will actuate the spring charging
motor and charge the breaker closing springs.
Push the sliding link located on the front of
the left track to the rear (Figure 41). This will
cause the negative interlock roller on the
breaker to depress and keep the breaker in the
trip free mode. Leave the sliding link in the
rear position and attempt to close the breaker
using the control switch. Nothing should
happen. Now attempt to close the breaker
by depressing the manual close button. The
closing springs will discharge but the breaker
should remain open. Return the sliding link to
the forward position.
Rack the circuit breaker into the connected
position and close either manually or
electrically. With the sliding link in the rear
position, attempt to close the breaker using
the control switch. Again, nothing should
happen. Now attempt to close the breaker by
depressing the manual close button. Again,
the closing springs will discharge but the
breaker should remain open.
If the interlock does not function as indicated
in either of the above cases DO NOT MAKE
ANY ADJUSTMENTS. Contact the nearest
Powell Service representative for additional
instructions.
G. SPRING DISCHARGE INTERLOCK
The spring discharge interlock consists of
a notched member in the right side track
assembly which activates the spring discharge
roller on the right side of the breaker
(Figure 42).
The function of the spring discharge interlock
is to prevent the breaker closing spring from
being charged unless the breaker is in the
“Connect” or “Disconnect/Test” position or
removed from the compartment. In addition,
it will mechanically discharge the breaker
springs when the breaker is moved between
any of the above mentioned positions and
prevent recharging by opening the close latch
monitoring switch in the breaker spring charge
circuit.
To test the function of the spring discharge
interlock, install a circuit breaker following the
instructions in Ch 5 Operation, B. Inserting the
Removable Element Into the Compartment. For
this test the control power circuits in the
metal-clad switchgear must be energized.
Place the breaker in the “Disconnect/Test”
position and connect the secondary disconnect
device by pulling down on the breaker handle
and inserting the level arm fully in the breaker.
This will actuate the spring charging motor and
charge the breaker closing springs.
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