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Per form a pickup test at system frequency, as outlined in the ACCEPTANCE TESTS
section.
In view o f the vital role o f protective relays in the operation o f a power system,
it is important that a periodic test program be follo\'ied.
interval between periodic checks will vary depending upon environment, type o f relay
and the user•s experience with periodic testing.
enough experience to
requirements, it is suggested that the points listed below be checked at an interval
o f from one to two years.
These tests are intended to make sure that the relays have not deviated from their
original settings.
serviced as described in the SERVICING section o f this manual.
T IME OVE RVO LTAGE UN IT
1.
Per form pickup test as described in the INSTALLATION section.
Per form the time tests as described in the INSTALLATION section.
2.
H IGH-SE ISM IC TARGE T AND SEA L- IN UN IT
)
1.
Check that the unit picks up at the values shown in Table V I I in the ACCEPTANCE
TESTS section
Check that the unit drops out at 25% or more o f tap value.
2.
H IGH-SE ISM I C INSTANTANE OUS UN IT
Per form a pickup test at system frequency, as outlined in the ACCEPTANCE TESTS
section.
C ONTA C T C LEAN ING
For cleaning relay contacts,
consists o f a flexible strip o f metal with an etched -roughened sur face, resembling
in e ffect a super fine file.
are le ft,
yet it will clean o ff any corrosion thoroughly and
flexibility o f the tool ensure s the cleaning o f the actual points o f contact.
Do not use knives,
contacts.
Knives
deterioration o f the contacts.
o f insulating abrasive material in the contacts and thus prevent closing.
The burnishing tool described above can be obtained from the factory.
PERIODIC CHECKS AND ROUTINE MAINTENANCE
select the test interval best
I f deviations are encountered, the relay must be retested and
.
a flexible burnishing tool should be used.
The polishing action is so delicate that no scratches
files, abrasive paper or cloth o f any kind to clean relay
or
files
may
Abrasive paper or cloth may leave minute particles
GEK-49865
Until the user has accumulated
leave
scratches
14
It is recognized that the
suited
to
his individual
rapidly.
which
increase
arcing
This
The
and
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