GE Industrial Solutions PowerVac PV-VL 13.8-1000-0 and -1 - Manual (Page 34)

Page 34 GEH 6468A - Power/Vac VL Breaker
To accomplish this, protective relays can be
adequately tested using field test sets. Specific
calibration instructions on particular devices
typically are provided by supplied instruction
books.
Instruction books supplied by manufacturers
address components that would normally require
service or maintenance during the useful life of the
equipment. However, they can not include every
possible part that could require attention,
particularly over a very long service period or
under adverse environments. Maintenance
personnel must be alert to deterioration of any part
of the supplied switchgear, taking actions, as
necessary, to restore it to serviceable status.
Industry publications of recommended
maintenance practices such as ANSI/NFPA 70B,
Electrical Equipment Maintenance, should be
carefully studied and applied in each user’s
formation of planned maintenance.
Some users may require additional assistance from
GE in the planning and performance of
maintenance. GE can be contacted to either
undertake maintenance or to provide technical
assistance such as the latest publications.
The performance and safety of this equipment may
be compromised by the modification of supplied
parts or their replacement by non-identical
substitutes. All such design changes should be
qualified by GE factory engineering.
The user should methodically keep written
maintenance records as an aid in future service
planning and equipment reliability improvement.
Unusual experiences should be promptly com-
municated to GE.
POWER/VAC
®
INTERRUPTER
The POWER/VAC interrupter used in this breaker
is a reliable, clean interrupting element. Since the
contacts are contained in a vacuum chamber, they
remain clean and require no maintenance at any
time. The metallic vapors eroded from the contact
surfaces during high current interruption remain in
the chamber and are deposited on metal shields
thus insuring a high dielectric value of the vacuum
and the walls of the interrupter.
TROUBLE REPORTING
Although all reputable manufacturers design their
products to perform satisfactorily with a minimum
of problems, the IEEE Switchgear Committee, an
organization of both users and manufacturers, rec-
ognized the need for a common trouble reporting
format. A reproducible copy of this form is included
on pages 67 and 68 of this book and is
recommended for use with any manufacturer's
circuit breakers. Forward completed forms to GE at
Burlington Iowa.
The intent is for each maintenance organization to
keep specific problem files with this information
documented. If the problem is serious or repetitive,
a summary should be sent to the appropriate
manufacturer for action. The level of detail
included on the form is considered very desirable
so that the manufacturer's investigator may more
thoroughly understand and solve the reported
problem.
14.2. SERVICE CONDITIONS
The frequency of required maintenance depends
on the severity of the service conditions of the
switch-gear application. If the service conditions
are mild, the interval between maintenance
operations may be extended to 10 years or 10,000
no load or 5000 for normal load switching
operations.
Mild service conditions are defined as an
environment in which the switchgear is protected
from the deleterious effects of conditions such as:
Salt spray.
Changes in temperature that produce
condensation, conductive and/or abrasive
dust.
Damaging chemicals and fumes.
Vibration or mechanical shock.
High relative humidity (90%).
Temperature extremes (below -30º C or above
+40º C).
WARNING: BEFORE ANY MAINTENANCE
WORK IS PERFORMED, MAKE CERTAIN THAT
ALL CONTROL CIRCUITS ARE DE-ENERGIZED
AND THAT THE BREAKER IS REMOVED FROM
THE METALCLAD UNIT. DO NOT WORK ON
THE BREAKER OR MECHANISM WHILE IT IS IN
THE CLOSED POSITION WITHOUT TAKING
PRECAUTIONS TO PREVENT ACCIDENTAL
TRIPPING. DO NOT WORK ON THE BREAKER
WHILE THE CLOSING SPRING IS CHARGED
UNLESS IT IS SECURED IN THAT POSITION BY
THE CLOSING-SPRING GAG.
14.3. FAULT INTERRUPTIONS
The erosion rate of the primary contacts in the
vacuum interrupters is very low for no-load and
normal load switching operations. However, fault
current interruptions at or near the breaker rating
may result in appreciable contact erosion. With
frequent fault interruptions it is necessary to