Acceptance Tests; Visual Inspection; Mechanical Rnspection; Electrical Tests - GE ICW51A Instructions Manual

Reasonable care should be exercised in un-
packing the relay. IT the relays are not to be
installed immediately, they should be stored in their
original cartons in a place that is free from mois-
ture, 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 in-
spection and acceptance test should be made to
insure that no damage has been sustained in shipment
and that the relay calibrations have not been dis-
turbed.
VISUAL INSPECTION
Check the nameplate stamping to insure 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. The drag magnet should
be fastened securely in'r position on its mounting
shelf. There must not be any metallic particles or
other foreign matter in the air gap of either the
wattmetric drive magnet or the drag magnet.
MECHANICAL INSPECTION
It
is recommended that the following mechanical
adjustments be checked:
1. On relays with an adjustable time dial (ICW51A
and ICW52B), the time dial will be locked at the No. 0
position by means of the two screws projecting
through the upper shelf of the die-case frame. With
the time dial at the zero position the moving contact
should just touch the stationary contact. There
should be sufficient clearance between the stationary
contact brush and its backing strip to allow for at
least 1/32" wipe. Loosen the two screws so that
the time dial can be turned. Then set the dial at the
approximate setting which will be used when the
relay is installed. On over-and under-power relays
(ICW52A) the relative positions of the upper and
lower contacts will have been set at the factory to
obtain the percent reset specified on the requisition,
or for 80 percent reset if no value was specified.
This setting should not be disturbed.
2. The disk and shaft assembly should have a ver-
tical end play of from 1/64" to 1/32". The set screws
for the upper pivot and lower jewel screw must be
tight. The disk should be approximately centered
in the air gap of both the wattmetric magnet as-
sembly and the drag magnet. The minimum per-
missible clearance between the disk and either the
wattmetric or drag magnet is .008". The disk and
shaft assembly should turn freely without noticeable
friction.
On Type ICW51A and ICW52B there is a stop arm
assembly located near the top of the disk shaft.
There should be approximately 1/64" deflection of
the leaf spring.
Power Relays Type ICW GEH-2056
4. Check the location of the contact brushes on the
cradle and case blocks against the internal con-
nection for the relay. Be sure that the shorting
bars are in the proper locations on the case block
and that the long and short brushes on the cradle
block agreee with the internal connection diagram.
Fig. 7 shows a sectional view of the case and
cradle blocks with connection plug in place. Note
that there is an auxiliary brush in each position on
the case block. This brush should be formed high
enough so that when the connection plug is inserted
it engages the auxiliary brush before striking the
main brush. This is especially important in cur-
rent circuits and other circuits with shorting bars
since an improper adjustment of the auxiliary brush
could result in a CT secondary circuit being mo-
mentarily open circuited.
5. The armature and contacts of the target and
seal-in unit (Type ICW51A and ICW52B) should move
freely when operaed by hand. There should be a
screw in only one of the tap positions on the right
stationary contact strip. Operate the armature by
hand and be sure the target latches in its exposed
position before the contacts close. There should be
at least 1/32" wipe on the seal-in contacts. With
the cover fastened securely in place, check that the
target resets positively when the reset button at the
bottom of the cover is operated.
ELECTRICAL TESTS
It is recommended that the following electrical
checks be made immediately upon receipt of the
relay. Note that all tests should be made with the
relay in its case and in a level position. The relay
should be "preheated" by energizing the potential
coil circuit at rated voltage for at least 15 minutes
prior to the tests.
1. Pickup - Connect the polarizing and operating
coil circuits of the relay as shown in Fig. 8. With
rated voltage applied to the potential circuit, and the
tap screw in the minimum tap position, the current
required to just close the left hand contact should be
within ~ 5 percent of the value obtained from the
following equation:
Where: Tm
v
2
3
(~)
V
Minimum tap in watts
Rated volts
(1)
2. Dropout -
In
the case of the Type ICW52B relay
the dropout watts, i.e. the watts at which the right
hand contact w.ill reclose as current in the operating
circuit is reduced, can also be checked by means of
Fig. 8. Dropout has been set at the factory as
specified on the requisition, or. at 80 percent of
pickup watts if no value was specified. This dropout
value should check within
~
5 percent.
3. Pickup Time (ICW51A & ICW52B) - Using the
test connections of Fig. 8, check operating time
from the No. 5 time dial setting with the tap screw
9