Page
xxxiv
IB131021EN
Effective Mar 2018
2. Power
Elements
Vacuum Interrupters
Contact wipe and Contact
erosion
Primary Disconnects
Adequate vacuum
Dirt on ceramic body
After short circuit
interruption or after
every 5000
operations/5years
(whichever comes first)
No burning or damage
Proceed with integrity check as
described in Paragraph 6-4
Visual Check
Refer to Paragraphs 5.2.2 & 6-5
Visual Check
If integrity check is not satisfactory,
replace interrupter assembly
Clean with lint-free cloth
If contact erosion is over max limit,
replace interrupter assembly. If contact
wipe is out of specified range, reset to
desired range
Replace if burned, damaged
or eroded
3. Control
Circuit
Parts
Charging, Closing, Tripping
Circuits
Wiring
Terminals
Correct operation by
control power
Securely tied in
proper place
Tight
Test charging, closing, and
tripping of the circuit breaker
twice
Visual Check
Visual Check
Replace any defective device. Identify
per Troubleshooting Chart
Repair or tie as necessary
Tighten or replace if necessary
4. Operating
Mechanism
Tightness of Hardware
Dust or Foreign Matter
Lubrication
Deformation or Excessive
Wear
Manual Operation
No loose or missing
Parts
No dust or foreign
matter
Smooth operation
and no excessive
wear
No excessive
deformation or wear
Smooth operation
Visual and by feel
Visual Check
Sight, feel and per maintenance
schedule
Visual and operational
Manual tripping
Refer to Table
6 . 1
and tighten or
reinstate if necessary with
appropriate tools
Clean as necessary
Refer to Paragraph 6-10
and lubricate very sparingly with
light mineral oil
Remove cause and replace parts
Correct per troubleshooting chart if
necessary
6-4
VACUUM INTERRUPTER INTEGRITY TEST
Vacuum interrupters used in Type VCP-WL Vacuum
Circuit Breaker Elements are highly reliable interrupting
elements. Satisfactory performance of these devices is
dependent upon the integrity of the vacuum in the
interrupter and the internal dielectric strength. Both of
these parameters can be readily checked by a one minute
ac high potential test. Refer to Table 6.2 (page 41) for the
appropriate test voltage. During this test, the following
warning must be observed:
WARNING
APPLYING ABNORMALLY HIGH VOLTAGE ACROSS A
PAIR OF CONTACTS IN VACUUM MAY PRODUCE X-
RADIATION. THE RADIATION MAY INCREASE WITH
THE INCREASE IN VOLTAGE AND/OR DECREASE IN
CONTACT SPACING. X - RADIATION PRODUCED
DURING THIS TEST WITH RECOMMENDED VOLTAGE