GE Industrial Solutions PowerVac PV-VL 13.8-1000-0 and -1 - Manual (Page 35)

GEH 6468A -Power/Vac VL Breaker Page 35
form maintenance based on the number of
interruptions. After each 15 full fault interruptions the
following should be performed:
1. Contact erosion check.
2. Wipe and gap check.
3. Vacuum interrupter integrity test.
14.4. CONTACT EROSION
Check in the breaker-closed condition per PRIMARY
CONTACT EROSION section 11.1. When erosion
reaches 1/8 inch, the interrupter should be replaced.
14.5. TRANSFER FINGER WEAR
With breaker open, examine the moving contact rod
projecting below the transfer fingers (10, Fig. 22).
Wipe off the lubricant in order to see the metal
surface condition. The finger locations should present
a burnished silver contact without copper appearance
at more than one location. If copper is visible at more
than one location per pole or the silver plating is torn,
the interrupter assembly should be replaced.
Relubricate with grease, part # 0282A2048P009
(mobil 28 red grease).
14.6. MECHANISM
Check all items covered in INSTALLATION and
readjust or tighten hardware as required. Lubricate as
recommended under LUBRICATION.
14.7. PRIMARY INSULATION PARTS
Using dry, non-linting cloth or industrial-type wipers,
clean accessible insulation surfaces on the interrupter
supports and operating rod insulators. In service
locations where contamination is heavy or external
flashovers, have occurred during interrupter high-
potential testing, remove the interrupter assemblies
per the procedure in REPAIR AND REPLACEMENT
and clean the inside surfaces of the interrupter
supports and the outer insulation surfaces of the
POWER/VAC interrupters.
Be sure to discharge the interrupter midband ring
before removing the interrupter assemblies. Removal
and reassembly of interrupter assemblies will
normally not require adjustment due to the design of
the interrupter operating rod insulator connection.
They should be returned to the same location from
which they were removed.
14.8. LUBRICATION
Proper lubrication is important for maintaining reliable
circuit breaker performance. The ML-18VL mech-
anism uses bearings which have a synthetic lining in
some locations. These bearings do not require
lubrication to maintain low friction, but lubrication
does not harm them and oiling lightly is
recommended. Sleeve bearings are used in some
linkage locations and needle or roller bearings are
used for low friction on trip shaft and close shaft.
Bearings are lubricated during factory assembly with
grease and oil, but all lubricants have a tendency to
deteriorate with age. Providing a fresh lubricant
supply at periodic intervals is essential to proper
breaker operation, especially where frequent
operation may have forced lubricant out of the
bearing
surfaces. Apply a few drops of light
synthetic machine oil such as Mobil 1 at each
bearing. Apply a coat of 0282A2048P009 grease on
the four corners of the closing spring guide where it
enters inside the spring. Metal-to-metal contact
surfaces should be cleaned and lubricated with
0282A2048P009 grease to provide cleanliness and
prevent oxidation.
Electrical primary contact surfaces also require
periodic lubrication to inhibit oxidation and minimize
friction. At each inspection and maintenance interval,
do the following:
1) Wipe clean and coat lightly with 0282A2048P009
grease all silvered primary contact surfaces such as
the movable contact rod of the interrupter and the
primary disconnect fingers.
2) Clean and coat lightly with 0282A2048P009 grease
the pins of the secondary coupler.
14.9. RECOMMENDED MAINTENANCE
The following operations should be performed at
each maintenance check:
1. Perform a visual inspection of the breaker. Check
for loose or damaged parts.
2. Perform slow closing operation described under
MECHANICAL CHECKING AND SLOW CLOSING.
3. Check the erosion indicator and the wipe and gap
as described under DIMENSIONAL CHECKS.
4. Perform the vacuum interrupter integrity test as
described under ELECTRICAL CHECKS.
5. Lubricate the breaker operating mechanism as
described under LUBRICATION.
6. Check the electrical operation using the test
cabinet.