Overhaul - Siemens GMSG Instruction Manual

Introduction
The following procedures along with the
troubleshooting charts at the end of this
section, provide maintenance personnel
with a guide to identifying and correcting
possible malfunctions of the type GMSG
vacuum circuit breaker.
Circuit breaker overhaul
Table 6: Overhaul schedule gives the
recommended overhaul schedule for a
type GMSG vacuum circuit breaker. These
intervals assume that the circuit breaker is
operated under "usual service conditions"
as discussed in ANSI/IEEE C37.20.2, section
8.1 and ANSI/IEEE C37.04, section 4, and
elaborated in ANSI/IEEE C37.010, section
4. If the circuit breaker is operated
frequently, the maintenance interval in
Table 6: Overhaul schedule may coincide
with the maintenance interval in Table 2:
Maintenance and lubrication schedule on
page 40.
When actual operating conditions are
more severe, overhaul periods should
occur more frequently. The counter on the
front panel of the circuit breaker records
the number of operations.
Circuit breaker
type
GMSG
Table 6: Overhaul schedule
High-potential tests employ hazardous voltages.
Will cause death, serious injury and property damage.
Read instruction manual. All work must be performed with the
circuit breaker completely de-energized and the springs
discharged. Limit work to qualified personnel.
Replacement at overhaul
The following components are replaced
during an overhaul of the circuit breaker,
when required:
Vacuum interrupters as determined by
vacuum-integrity test, contact erosion
or after 10,000 operations
Spring-release coil, 52SRC
Shunt-trip coil, 52T
Auxiliary switch.
When these parts are changed, locking
devices must also be removed and
replaced. These include lock washers,
retaining rings, retaining clips, spring pins,
cotter pins, etc.
1. Replace vacuum interrupters,
instructions follow (refer to page 49).
2. Spring-release coil (52SRC) or shunt-
trip coil (52T).
A. Remove two "push on" terminal
B. Remove two M4 hex-head screws
and dismount solenoid.
C. Install replacement solenoids with
Number of
closings
10,000
connections
two M4 hex-head screws and new
lock washers.

Overhaul

53