Westinghouse KC-4, Installation, Operation & Maintenance Instructions Manual

Page: 106 / 178

TYPE KC-2 H I G H S PEED OVERC U R RENT
2 . The contact gap adjustment for the overcurrent
unit is m ade with the moving contact in the
reset position, i.e., against the right side of the
bridge.
M ove in the left-hand stationary contact until
it just touches the moving contact. Then back
off the stationary contact of 2/3 of one turn for
a contact gap of approximately .020" .
The clamp holding the stationary contact need
not be loosened for the adjustment since the
clamp utilizes a spring-type action in holding
the stationary contact in position.
With the tap screw in the desired tap hole, pass
rated ac current through the relay terminals.
The sensitivity adjustment is made by varying
the tension of the spiral spring attached to the
moving element assembly. The spring is ad­
justed by placing a screwdriver or similar tool
into one of the notches located on the periphery
of the spring adjuster and rotating it. The spr­
ing adjuster is located on the underside of the
bridge and is held in place by a spring type
clamp that does not have to be loosened prior
to making the necessary adjustments.
Adjust the spring until the contacts close.
With this adjustment, the pick-up of the relay
for any other tap setting should be within ±5%
of tap value.
If settings in between taps are desired, place the
tap screw in the next lower tap hole and adjust
the spring until the contacts just close at the
desired pick-up current.
IN DICATI N G C O N TACTOR SWITCH ( I C S )
Close the main relay contacts and pass suf­
ficient de current through the trip circuit to close
the contacts of the ICS. This value of current
should be not less than 1 .0 ampere nor greater
than 1 .2 amperes for the 1 ampere ICS. The
current should not be greater than the particular
I CS tap setting being used for the 0.2-2 .0 ampere
ICS. The operation indicator target should drop
freely.
The contact gap should be approximately
0.047" for the 0.2/2.0 ampere unit and 0.070" for
the 1 .0 ampere unit between the bridging moving
contact and the adjustable stationary contacts.
The bridging moving contact should touch both
stationary contacts simultaneously.
RENEWAL PARTS
Repair work can be done most satisfactorily at
the factory. However, interchangeable parts can
be furnished to the customers who are equipped
for doing repair work. When ordering parts,
always give the complete nameplate data:
RATI N G S
OF
OVER C U R R E NT U NIT
50 & 60 Hz
Range
Continuous One Second
Rating Amps Rating Amps
. 5 - 2 5 100
5 - 4
8 140
2 - 8
8
1 40
4 - 1 6 1 0 200
1 0 - 40
10 200
4
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