Time-Overcurrent Unit; Standard Instantaneous Unit; High Dropout Instantaneous Unit; Target And Seal-In Unit - GE IAC66K Instructions Manual

TIME-OVERCURRENT UNIT

With the tap plug in the minimum position and the time dial set in the No. 1/2 position, check the
current required to just close the contact.
the tap block.
The operating time from the Number 5 time-dial setting at five times minimum pickup setting should be
within seven percent of the value shown in Fig. 1.
With the time dial at No. 10 time setting and the tap plug in the lowest tap, apply sufficient current
in the relay to definitely close the contacts.
should reset all the way to the No. 10 dial-setting position.

STANDARD INSTANTANEOUS UNIT

With the target in the down position, check the pickup at the minimum calibration mark using rated fre­
quency. The pickup current should be within �15 percent of the minimum rating on the nameplate.

HIGH DROPOUT INSTANTANEOUS UNIT

Set the unit for the minimum calibration shown by the nameplate rating.
the pickup current should be within �15 percent of the minimum rating on the nameplate.
Dropout current should be at least 80 percent of the minimum rating on the nameplate.

TARGET AND SEAL-IN UNIT

PICKUP AND DROPOUT TEST
1. Connect relay studs l and 2 (see internal connections diagram) to a DC source, ammeter and load
box so that the current can be controlled over a range of 0.1 to 2.0 amperes.
2. Turn the time dial to the ZERO TIME-DIAL position.
3. Increase the current slowly until the seal-in unit picks up.
4. Move the time dial away from the ZERO TIME-DIAL position; the seal-in unit should remain in the
picked up position.
5. Decrease the current slowly until the seal-in unit drops out.

LOCATION

The location should be clean and dry, free from dust and excessive vibration, and well lighted to
facilitate inspection and testing.

MOUNTING

The relay should be mounted on a vertical surface.

CONNECTIONS

The internal connection diagram is shown in Fig. 3.
Fig. 4.
One of the mounting studs or screws should be permanently grounded by a conductor not less than No. 12
B&S gage copper wire or its equivalent.
GEI-44233
It should be within +5 percent of the minimum pickup shown on
Reduce the current to 75 percent of tap value and the disk
TABLE VI
PICKUP
TAP
CURRENT
0.2 0.15-0.195
2.0
1.50-1.9 5

INSTALLATION

7
With rated frequency applied,
See Table VI.
See Table VI.
PICKUP
CURRENT
0.05 OR MORE
0.55 OR MORE
The outline and panel diagram is shown
A typical external wiring diagram is shown in
in
Fig. 7.