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41-116K
Apply the indicated current per Table 1 for the electro-
magnet plug adjustment (e.g., COV-8, 20 times tap
value) and measure the operating time. Adjust the
proper plug until the operating time corresponds to the
value in Table 1. (Withdrawing the left-hand plug, front
view, increases the operating time and withdrawing the
right-hand plug, front view, decreases the time.) In
adjusting the plugs, one plug should be screwed in
completely and the other plug run in our out until the
proper operating time has been obtained.
Recheck the permanent magnet adjustment. If the
operating time for this calibration point has changed,
readjust the permanent magnet and then recheck the
electromagnet plug adjustment.
6.3.2. Indicating Contactor Switch Unit (ICS)
Close the main relay contacts and pass sufficient dc
current through the trip circuit to close the contacts of
the ICS. This value of current should not be greater
than the particular ICS tap setting being used. The
indicator target should drop freely.
6.3.3. Indicating Instantaneous Trip Unit (IIT)
The core screw must be adjusted to the value of
pickup current desired.
The nameplate data will furnish the actual current
range that may be obtained from IIT unit.
6.3.4. Voltage Unit (V)
A. The upper pin bearing should be screwed down
until there is approximately .025" clearance
between it and the top of shaft bearing. The
upper pin bearing should then be securely
locked in position with the lock nut. The lower
bearing position is fixed and cannot be adjusted.
B. The contact gap adjustment for the directional
unit is made as follows:
With the moving contact in the normally closed
position, i.e., against the left stop on bridge,
screw in the stationary contact until both con-
tacts just close as indicated by a neon lamp in
the contact circuit. Then, screw the stationary
8
Type COV Voltage
Controlled Overcurrent Relay
contact in towards the moving contact an addi-
tional one-half turn. The clamp holding the
stationary contact housing need not be loosened
for the adjustment since the clamp utilizes a
spring-type action in holding the stationary con-
tact in position.
C. The sensitivity adjustment is made in two steps.
The voltage unit should be energized for one
hour before these adjustment are made.
1) The adjustable resistor, located at the rear of
the voltage unit, is adjusted such that the maxi-
mum resistance is in the circuit (Approximately
2500 ohms).
2) The tension of the spiral spring, attached to
the moving element assembly, is then varied.
The spring is adjusted by placing a screwdriver
or similar tool into one of the notches located on
the periphery of the spring adjuster and rotating
it. The spring adjuster is located on the under-
side 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.
The spring is to be adjusted such that the contacts will
close as indicated by a neon lamp in the contact circuit
when the applied voltage is reduced to 80 volts. The
contacts should open with 80 plus volts applied.
Any setting other than the 80 volts then can be made
by adjusting the resistor for the desired contact clos-
ing voltage.
7.0 RENEWAL PARTS
Repair work can be done most satisfactorily at the
factory. However, interchangeable parts can be fur-
nished to the customers who are equipped for doing
repair work. When ordering parts, always give the
complete nameplate data.
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