3
I. Inspect wiring connections for
tightness.
tightness.
j. Check after servicing circuit breaker
to verify the contacts move to the fully
opened and fully closed positions,
that there is an absence of friction or
binding, and that electrical operation
is functional.
to verify the contacts move to the fully
opened and fully closed positions,
that there is an absence of friction or
binding, and that electrical operation
is functional.
SECTION 4 - MAINTENANCE OF
MEDIUM-VOLTAGE CIRCUIT
BREAKERS
MEDIUM-VOLTAGE CIRCUIT
BREAKERS
4.1. FREQUENCY OF MAINTENANCE.-
Medium-voltage circuit breakers which
operate in the range of 600 to 15,000
volts should be inspected and maintained
annually or after every 2,000 operations,
whichever comes first. The above
maintenance schedule is recommended
by the applicable standards to achieve
required performance from the breakers.
Medium-voltage circuit breakers which
operate in the range of 600 to 15,000
volts should be inspected and maintained
annually or after every 2,000 operations,
whichever comes first. The above
maintenance schedule is recommended
by the applicable standards to achieve
required performance from the breakers.
4.2. SAFETY PRACTICES.- Maintenance
procedures include the safety practices
indicated in the ROMSS (Reclamation
Operation & Maintenance Safety
Standards) and following points that
require special attention.
procedures include the safety practices
indicated in the ROMSS (Reclamation
Operation & Maintenance Safety
Standards) and following points that
require special attention.
a. Be sure the circuit breaker and its
mechanism are disconnected from all
electric power, both high voltage and
control voltage, before it is inspected
or repaired.
mechanism are disconnected from all
electric power, both high voltage and
control voltage, before it is inspected
or repaired.
b. Exhaust the pressure from air re-
ceiver of any compressed air circuit
breaker before it is inspected or re-
paired.
ceiver of any compressed air circuit
breaker before it is inspected or re-
paired.
c. After the circuit breaker has been
disconnected from the electrical
power, attach the grounding leads
properly before touching any of the
circuit breaker parts.
disconnected from the electrical
power, attach the grounding leads
properly before touching any of the
circuit breaker parts.
d. Do no lay tools down on the equip-
ment while working on it as they may
be forgotten when the equipment is
placed back in service.
ment while working on it as they may
be forgotten when the equipment is
placed back in service.
4.3. MAINTENANCE PROCEDURES
FOR MEDIUM-VOLTAGE AIR CIRCUIT
BREAKERS.- The following suggestions
are for use in conjunction with
manufacturer's instruction books for the
maintenance of medium-voltage air circuit
breakers:
FOR MEDIUM-VOLTAGE AIR CIRCUIT
BREAKERS.- The following suggestions
are for use in conjunction with
manufacturer's instruction books for the
maintenance of medium-voltage air circuit
breakers:
a. Clean the insulating parts including
the bushings.
the bushings.
b. Check the alignment and condition
of movable and stationary contacts
and adjust them per the
manufacturer's data.
of movable and stationary contacts
and adjust them per the
manufacturer's data.
c. See that bolts, nuts, washers, cot-
ter pins, and all terminal connections
are in place and tight.
ter pins, and all terminal connections
are in place and tight.
d. Check arc chutes for damage and
replace damaged parts.
replace damaged parts.
e. Clean and lubricate the operating
mechanism and adjust it as described
in the instruction book. If the operat-
ing mechanism cannot be brought
into specified tolerances, it will usually
indicate excessive wear and the need
for a complete overhaul.
mechanism and adjust it as described
in the instruction book. If the operat-
ing mechanism cannot be brought
into specified tolerances, it will usually
indicate excessive wear and the need
for a complete overhaul.
f. Check, after servicing, circuit
breaker to verify that contacts move
to the fully opened and fully closed
positions, that there is an absence of
friction or binding, and that electrical
operation is functional.
breaker to verify that contacts move
to the fully opened and fully closed
positions, that there is an absence of
friction or binding, and that electrical
operation is functional.
(FIST 3-16 1/92)