GEK-49865
The primary adjustment for the time o f operation o f the unit is made by means o f the
time dial.
HO\'Jever, further adjustment is obtained by moving the permanent magnet
along its supporting shelf; moving the magnet toward the disk and sha ft decreases the
time, while moving it away increases the time.
Pickup Test
Set the relay at the
0.5
time-dial position and the lowest tap.
Using the test
connections in Figure 11, the main unit should close the contacts within
�
4% o f tap
value at rated frequency.
For frequency-compensated relays, pickup must be within 7.5% from
50��
to
150%
o f
system frequency.
Time Test
Set the relay to the No.
5
time-dial setting and the tap as shown in Table V I.
Using the test connection in Figure 11, apply 130% o f tap voltage to the relay. The
relay operating times to close its contact are listed in Table V I.
TABLE V I
Relay
Tap
Volts Applied
Frequency
Min.
Max.
IFV51AD
128
166.4
60
113
146.9
50
9.3
9.6
I FV71AD
&
BD
128
166.4
50 or 60
HIGH-SE ISM IC TARGET AND SEAL- IN UNIT
The target and seal-in unit has an operating coil tapped at
0.2
and 2.0 amperes.
The relay is shipped from the factory with the tap screw in the higher ampere
position.
The tap screw is the screw holding the right-hand stationary contact.
To
change the tap setting, first remove one screw from the le ft-hand stationary contact
and place it in the desired tap. Next, remove the screw from the undesired tap and
place it on the left-hand stationary contact, where the first scre\'J was removed.
See Figure 1.
This procedure is necessary to prevent the right-hand stationary
contact from getting out o f adjustment. Screws should
never
be left in
both
taps at
the same time.
and
Test
1.
Connect relay studs 1 and
2
(see the test circuit o f Figure
12)
to a D C source,
ammeter and load box, so that the current can be controlled over a range o f 0.1
to 2.0 amperes.
2.
Turn the time dial to the ZE RO
(0)
time-dial position.
3.
Increase the current slowly until the seal-in unit picks up. See Table V I I.
4.
t1ove the time dial away from the ZE RO time-dial position; the seal-in unit
should remain in the picked-up position.
12
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