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36
PowlVac® CDR 27kV &38kV Vacuum Circuit Breaker
IB-65020A
Maintenance
The procedure for spring removal is as
follows:
1. With the main closing spring discharged
and the circuit breaker contacts open,
remove the bolt at the top of the spring
rod together with the flat washer and
lock washer.
2. Remove the horizontal bracket at
the top of the main closing spring by
unfastening the two attachment bolts.
3. Remove the spacer from below the
bracket.
4. Turn the bracket 90˚, and replace it on
the top of the spring yoke.
5. Place the spacer above the bracket with
the flat washer above the spacer.
6. Insert bolt and tighten until the tension
is taken off the connecting rods.
7. With a slight rocking motion of the
main closing spring assembly, the
connecting rods (Figure 17, e) can now
be unhooked from the spring yoke pins
and the main closing spring assembly
can be removed.
Note:
Care should be taken on reassembly
to ensure correct location of the flat
washer, lock washer and spacer
(Figure 18).
Figure 18 Main Closing Spring Assembly
Installed
a. Bolt
b. Bracket
c. Lock Washer
d. Flat Washer
e. Spacer
e
d
c
a
b
4) Slow Closing of Mechanism
The slow closing of mechanism described
is not required for routine maintenance;
however, it may be a useful procedure
for troubleshooting circuit breaker
misoperation.
1. With the main closing spring assembly
removed, rotate the camshaft so that
the crank arms are pointing downward.
The fundamental linkage will now move
into the reset position.
2. Push the manual close operator inward
and hold it in while operating the
charging handle to rotate the camshaft.
3. When the close release latch arm has
passed the close shaft latch plate, the
manual close operator may be released.
As the main closing cam engages
the main cam roller, the jackshaft will
commence to rotate.
