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GEK-49822
INSTANTANEOUS UNIT
Check that the instantaneous unit picks up at the desired current level, as outlined
in the ACCEPTANCE TESTS and the OPERATION sections.
SERVICING
These relays are adjusted at the factory and it is advisable not to disturb the
adjustments.
If, for any reason, they have been disturbed or it is found during
installation or periodic testing that the relay is out of limits, the checks and
adjustments
outlined
in
the
following
paragraphs
should
be
observed.
It
is
suggested that this work be done in the laboratory.
TARGET AND SEAL-IN UNIT
Repeat the visual
and mechanical
inspections and the pickup and dropout current
checks as outlined in the ACCEPTANCE TESTS section.
TIME OVERCURRENT UNIT
Disk and Bearings
The jewel
should be turned up until
the disk is centered in the air gaps, after
which it should be locked
in
this
position
by the set
screw provided
for this
purpose.
The upper bearing pin should next be adjusted so that the disk shaft has
about 1/64 inch end play.
Contact Adjustment
The contacts should have about 1/32 inch wipe.
That is, the stationary contact tip
should be deflected about 1/32 inch when the disk completes its travel.
Wipe is
adjusted by turning the wipe adjustment screw on the stationary contact, thereby
adjusting the position of the brush relative to the brush stop.
When the time dial is moved to the position where it holds the contacts just closed,
it should indicate 0 on the time-dial scale.
If it does not and the brushes are
correctly adjusted, shift the dial by changing the position of the arm attached to
the shaft just below the time dial.
Loosen the screw clamping the arm to the shaft
and turn the arm relative to the shaft until the contacts just make for 0 zero time-
dial setting.
Characteristics Check and Adjustments
Repeat
the
portions
of
the
ACCEPTANCE
TESTS
section
that
apply
to
the
time
overcurrent unit.
Also, check reset voltage and time as outlined under RESET in the
CHARACTERISTICS
section;
low
reset
voltages
or
long
reset
times
may
indicate
excessive friction caused by a worn bearing or by mechanical interference.
20
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