Time Overcurrent Unit - GE IBCG51M*Y1A Series Instruction Manual

GEK-49822
MOUNTING
The relay should be mounted on a vertical surface.
The outline and panel drilling
diagram is shown in Figure 26.
CONNECTIONS
The internal connection diagrams for the various relays are shown in Figures 5 to 9.
Typical external wiring diagrams are shown by Figures 10, 11 and 12.
Unless mounted on a
steel panel which adequately grounds the relay case,
it is
recomended that the case
be grounded through a mounting stud or
screw with
a
conductor not less than 1/12 B&S gage copper wire or its equivalent.
INSPECTION
At the time of installation, the relay should be inspected for tarnished contacts,
loose
screws, or other
imperfections. If any trouble
is found, it should be
corrected in the manner described in the section on SERVICING.
CAUTION
Every circuit in
the drawout case has
an auxiliary brush.
It
is
especially important on current circuits and other circuits with shorting
bars that the auxiliary brush be bent high enough to engage the connecting
plug or
test plug before
the main brushes do. This will
prevent CT
secondary circuits from being opened.
Refer to Figure 21.
OPERATION
Before the relay is put into service, it should be given a check to determine that
factory adjustments have not been disturbed.
The time dial will be set at 0 before
the relay leaves the factory.
If the setting has not been changed,
it will be
necessary
to change this
setting in order
to
open
the
time
overcurrent unit
contacts.
The following tests are suggested:
TARGET AND SEAL-IN UNIT
1. Make sure that the tap screw is in the desired tap.
2.
Perform pickup and dropout tests as outlined in the ACCEPTANCE TEST section.
TIME OVERCURRENT UNIT
1.
Set tap screw on desired tap.
Using the test circuit in Figure 22, apply
approximately twice tap value current until
the contacts just close. Reduce
the current until
the light in series with the contacts begins to
flicker.
This value of current should be within 5% of tap value.
2.
Check the operating time at some multiple of tap value.
This multiple of tap
value may be 5 times tap rating or the maximum fault current for which the
relay must coordinate.
The value used is left to the discretion of the user.
Use the test circuit shown in Figure 23.
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