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GEK—5583
INDUCTION UNIT
Pickup
The relay must be tested in its own case or equivale nt steel case.
Connect the
relay as shown in the test diagram of Figure 15 for the A and B connections only.
Set the time dial
at the 1/2 time dial
position .
Apply 110% of the pickup
current listed on the nameplate.
After the contact makes, reduce the current slowly
until
the contact just opens, increase the current slightly, and the relay contact
should just make.
A flickerin g indicatin g light is considered a contact closure.
The pickup should be within .j 2% of nominal, and can be adjusted with the control
spring sprocket located between the control
spring and moving contact.
There are
notches in the sprocket that can be used to turn the assembly with a screw driver.
Turning the sprocket to the right increase s the pickup value.
Turning
it to the
left decreases the pickup.
Reset
Remove the pickup current.
Turn the time dial to the No.10 position .
Turn the
disk by hand to close the normally-open contacts .
Release
the disk,
and
it
should
reset
to
the stop at the No.10 time dial
position .
If the disk stops somewhere in its travel, look for excessiv e friction,
parts that may be touching, or foreign matter in the drag magnet air gap.
Time Tests
Figure 9 is the operatin g-time curve with zero-rest raint current.
Figure
10
is
the
operatin g-time
curve with
2.5
and
5.0
amperes
restraint
current with the relay set in the 115% slope tap.
The time—curve settings can he verified using the connections for pickup for
the Figure 9 curve and
the slope connections for the Figure 10 curve.
The time
curve can be varied by moving the drag magnet on the shelf of the relay unit frame.
Moving the magnet inwards towards the disk shaft makes the time faster; moving it
away from the shaft makes the time longer.
Do not move the magnet outward past the
serration s on
the disk,
because it begins to loose
its effective ness beyond
that
point.
Slope Tests
Refer to Table IV and Figure 15.
Connect the relay as shown in Figure 15.
Set
the slope at 115%.
Set the time dial to the 1/2 time dial position .
Set the restraint current (IR); then apply the operatin g current (10) as listed
in Table IV.
It is best if this test is done on a 'go
—
no go" basis because the
magnitude of the test currents will overheat the units and lower the actual slope
setting.
The "go
-
no go" method is as follows:
9
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