GEI-50261
Reasonable care should be exercised in unpacking the relay in order that none of the
parts are injured nor the ad justments disturbed.
If the relays are not to be installed immediately, they should be stored in their
original cartons in a place that is free from moisture, dust and metallic chips.
Foreign matter collected on the outside of the case may find its way inside when the
cover is removed, and cause trouble in the operation of the relay.
ACCEPTANCE
TESTS
Immediately upon receipt of the relay, an inspection and acceptance test should be
made to make sure that no damage has been sustained in shipment and that the relay
calibrations have not been disturbed.
Visual
Check the nameplate stamping to make sure that the model number, rating and
calibration range of the relay received agree with the requisition.
Remove the relay from its case, and check by visual inspection that there are no
broken or cracked molded parts or other signs of physical damage, and that all
screws are tight.
Mechanical
It is recommended that the telephone-type relay be checked as follows:
With the telephone-type relay de-energized, each normally-open contact should have a
gap of
.010-.015
inch.
Observe the wipe on each normally-closed contact by
deflecting the stationary contact member towards the frame.
Wipe should be
approximately
.005
inch.
The wipe on each normally-open contact should be approximately
.005
inch.
This can
be checked by inserting a
.005
inch shim between the residual screw and the pole
piece and operating the armature by hand.
The normally-open contacts should make
before the residual screw strikes the shim. When the telephone relay is picked up,
the normally-closed contact should have a gap of
.010
to
0.15
inch.
Electrical Tests
If the relay has not been damaged in shipment, it is very unlikely that the relay
adjustments have been disturbed.
Where evidence of rough handling is observed, the
following electrical tests should be made.
1.
Balanced three-phase tests
Connect a balanced three-phase voltage of correct phase sequence,
rated
frequency and good wave form to the relay, as shown in Figure
7,
and check the
voltage across relay studs
3
and
4
with a high-resistance voltmeter
(1000
ohms
per volt or more).
The voltage observed should be less than
1.5
volts for a
208
volt relay, and
1.0
volts for a
120
volt relay.
8
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