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Immediately upon receipt of the relay, an inspection and acceptance test should be
made to insure that no damage has been sustained in shipment, and that the relay
calibrations have n ot been disturbed.
readjustment is necessary, refer to
VISUAL INSPECTION
Check the nameplate stamping to insure that the model number and rating of the
relay agree with the requisition.
are n o broken or cracked molded parts or other signs of physical damage, and that all
screws are tight.
MECHANICAL INSPECT ION
1 .
There should be no n oticeable friction in the rotating structure of the units.
2.
Make sure the control springs are not def ormed, and that spring convolutions do
n ot touch each other.
3.
With the relay well-leveled in its upright position, the left contacts of both
units must be open.
right contact.
Check the location of the contact brushes on the cradle and case blocks against
4.
the internal connection diagram f or the relay.
The rotating shaft end play should be 0. 005 inch to 0. 010 inch.
5.
The contact gap should be 0. 018 inch t o 0.020 inch.
6 .
The contact wipe should be 0. 003 inch to 0.006 inch.
7 .
ELECTRICAL CHECKS - OHM UNIT
All tests should be made with the relay in its case. Bef ore any electrical checks
are made on the units, the relay should be connected as shown in Figure 128, and allowed
to warm up f or approximately 15 minutes with the potential circuit alone energized at
rated v oltage, and the restraint taps set at 100 percent.
prior to factory adjustment, and if they are rechecked when cold, they will have a
tendency to underreach by three or four percent.
course, essential.
Check the factory setting and calibration by means of the tests described in the
following sections.
settings should not be disturbed unless the f ollowing checks indicate conclusively that
the settings have been disturbed. If readjustments are necessary, refer to the section
on
for recommended procedures.
SERVICING
GEK-49778
ACCEPTANCE TESTS
SERVICING.
Remove the relay from its case and check that there
The moving contacts of the units should rest against the
The units were carefully adjusted at the factory, and these
If examination or test in dicates that
Accurately calibrated meters are, of
12
The units were warmed up
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