28
Maintenance
Damper Assembly Check (for circuit breakers equipped
with all vacuum interrupters except type VS-15050)
GMI circuit breakers contain a viscous damper assembly,
shown in
Figure 37a
, and described in some detail on page
16, and in
Figure 19a
.
While performing the manual spring charging check, a
simple check of the damper mounting yoke, pin, retaining
rings, and the nut for tightness should be completed.
The cylindrical surface of the damper and telescoping tube
should be well greased. The full periphery of the tube and
cylinder should be coated with Beacon 325.
Damper Assembly Check (for circuit breakers equipped
with type VS-15050 vacuum interrupters)
GMI circuit breakers contain a viscous damper assembly,
shown in
Figure 37b
, and described in some detail on page
16 and in
Figure 19b
.
While performing the manual spring charging check, a
simple check of the damper mounting adapter, pin,
retaining rings, X-washer, and other hardware for tightness
should be completed.
The outer surface of the damper and telescoping cylinder
should be well greased. The full inner periphery of the
cylinder and outer surface of the damper should be coated
with Beacon 325.
Electrical Control Checks
The electrical controls of the GMI circuit breaker should be
checked during inspections to verify absence of any
mechanical damage, and proper operation of the automatic
spring charging and Close and Trip circuits.
Unless otherwise noted, all of these tests are performed
without
any control power applied to checks and the circuit
breaker.
Check of the Wiring and Terminals
1. Physically check all of the circuit breaker wiring for
evidence of abrasion, cuts, burning or mechanical
damage.
2. Check all terminals to be certain they are solidly
attached to their respective device.
Check of the Secondary Disconnect
In addition to checking the terminals of the secondary
disconnect, the secondary contact fingers need to be free to
move without binding. Depress each finger, confirm
presence of spring force (contact pressure), and verify
freedom of motion.
Figure 37a:
Damper Assembly (for all circuit breakers
except those with type VS-15050 vacuum interrupter).
Figure 37b:
Damper Assembly (for circuit breakers
equipped with type VS-15050 vacuum interrupter).