GE Industrial Solutions PowerVac PV-VL 13.8-1000-0 and -1 - Manual (Page 36)

Page 36 GEH 6468A - Power/Vac VL Breaker
CAUTION: REPEATED OPERATIONS AT A RATE
EXCEEDING TWO PER MINUTE MAY CAUSE
CHARGING MOTOR OVERHEATING AND
SUBSEQUENT MOTOR FAILURE.
7. Examine the movable contact rod of the vacuum
interrupter. With the breaker open, wipe the lubricant
off the rod and examine the silver surface. The rod
should have a burnished appearance without copper
appearing through the silver. If copper is visible at
more than one location per pole, or if the silver
plating is torn, the interrupter assembly should be
replaced. Relubricate breaker movable contact rod
with 0282A2048P009 grease.
8. If desired, perform the additional tests (Megger,
Primary and Secondary High Potential, and Primary
Circuit Resistance). See ELECTRICAL CHECKS.
15. TIMING
Timing and speed checks are optional and also
depend on the level of maintenance performed.
Generally these tests are not required for normal
maintenance. If a new mechanism has been installed
or extensive repair, replacement or major
disassembly has been performed, it is recommended
that these tests be performed.
To determine contact velocity, a travel recorder and
oscillograph are required. Optional travel recorders
can be obtained through your local GE Sales Office
by ordering part number 0144Dl235G001. A typical
travel trace and interpretation are shown in Fig. 29.
Timing may be checked by monitoring control circuit
voltage and using no more than six volts DC and one
ampere through the vacuum interrupter contact to
indicate closed or open condition. Typical time
ranges vary with coil voltage, but nominal values are:
Initiation of trip signal to contact parting
32-45 Milliseconds
2 Milliseconds maximum pole spread
Initiation of close signal to contact closing
35-75 Milliseconds
2 Milliseconds maximum pole spread.
Trip-free operation may be checked by applying a
simultaneous close and trip signal, and a minimum
reclose operation may be checked by tripping a
charged breaker open while maintaining a close
signal.
Instantaneous reclose time 85-150 Milliseconds.
*Time from application of trip signal until
breaker contacts reclose.
16. OPENING AND CLOSING SPEED
The opening speed is modified by moving the speed
adjusting nuts on the opening spring assemblies. A
change in the opening speed affects the closing
speed Reference Figure 29.
The operating speeds for 5 cycle breakers are as
follows:
Operation Feet Per Second
Open 5.0 normal, 4.5 minimum
Close 3.5 nominal, 4.0 maximum
17. REPAIR AND REPLACEMENT
17.1.GENERAL
The following information covers in detail the proper
method of removing various parts of the breaker in
order to make any necessary repairs. This section
includes only those repairs that can be made at the
installation site, or parts of the breaker that are most
subject to damage.
Important: Upon completion of any kind of repair
work, all interrupter and mechanism adjustments
must be checked.
Refer as needed to sections on mechanical and
electrical adjustments.
17.2. REPLACEMENT OF INTERRUPTER
ASSEMBLIES
Interrupter are supplied in complete interrupter
assemblies which include the vacuum interrupter
mounted in the interrupter support, the primary studs
and disconnect fingers.
CAUTION: DO NOT ATTEMPT TO REMOVE OR
REINSERT THE VACUUM INTERRUPTER IN THE
INTERRUPTER SUPPORT ASSEMBLY. SPECIAL
TOLLS AVAILABLE ONLY AT THE FACTORY ARE
REQUIRED.
1 . Remove the front portion of the breaker top plate.
Close the breaker and remove the coupling clamp,
(8, Fig. 22). Hold hex projection (6, Fig. 22) at the
bottom of the operating rod insulator with a 1 inch
wrench and loosen the adjacent lock nut with a 3/4
inch wrench. Screw down the lock nut and the
operating rod insulator until clear of interrupter rod.
Remove the four bolts holding the pole assembly to
the mechanism and remove the old pole assembly.
2. Set the new pole assembly in place and install the
four mounting bolts. Set the pole assembly so that
the distance between the primary studs and the studs
on the adjacent pole are ten (10) inches center line to
center line.