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transit. If injury or damage resulting from rough handling is evident, file a damage claim at once with the
transportation company and promptly notify the nearest General Electric Apparatus Sales Office.
Reasonable care should be exercised in unpacking the relay in order that none of the parts are injured
or the adjustments 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 'nside when the cover is removed and cause trouble in the operation of the relay.
Immediately upon receipt of the relay, an inspection and acceptance tests should be made to insure that
no damage has been sustained in shipment and that the relay calibrations have not been disturbed. If the
examination or test indicates that readjustment is necessary, refer to the section on SER VICING.
VISUAL INSPECTION
Check the nameplate stamping to insure that the model number and rating of the relay agree with the
requisition.
Remove the relay from its case and check that there are no broken or cracked molded parts or other signs
of physical damage, and that all screws are tight.
MECHANICAL INSPECTION
1.
It is recommended that the mechanical adjustments in Table VIII be checked.
2. There should be no noticeable friction in the rotating structure of the units.
3.
Make sure control springs are not deformed and spring convolutions do not touch each other.
4.
With the relay well leveled in its upright position the contacts of all three units must be open. The
moving contacts of the units should rest against the backstop.
The armature and contacts of the seal-in unit should move freely when operated by hand. There should be
5.
at least 1/32 inch wipe on the seal-in contacts.
Check the location of the contact brushes on the cradle and case blocks against the internal connection
6.
diagram for the relay.
ELECTRICAL CHECKS - MHO UNITS
All tests must be made with relay in case.
relay should be connected as shown in F1g. 11 and be allowed to warm up for approximately 15 minutes with the
potential circuit alone energized at rated voltage and the restraint taps set at 100 percent. The units
were warmed up prior to factory adjustment and if rechecked when cold will tend to underreach by 3 or 4 per
cent. Accurately calibrated meters are, of course, essential.
It is desirable to check the factory setting and calibration by means of the test described in the fol
lowing sections. The mho units were carefully adjusted at the factory and it is not advisable to disturb
these settings unless the following checks indicate conclusively that the settings have been disturbed.
readjustments are necessary refer to the section on SERVICING for the recommended procedures.
Test connections for checking correct mho unit operation.
(a)
Control Spring Adjustment
Be sure that the relay is level in its upright position.
Fig. 11 and leave the restraint taps in the 100 percent position.
GEK-45495
ACCEPTANCE T ESTS
TABLE VIII
CHECK POINTS
R otating Shaft End Play
Contact Gap
Contact Wipe
Before any electrical checks are made on the mho units the
9
MHO UNITS
.010 - . 015 inch
. 14 5 - .155 inch
. 003 - . 005 inch
Leave the relay connected as shown in
If
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