GE IAC66K, Instructions Manual

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GEI-44233
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. It should be within +5 percent of the minimum pickup shown on
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. Reduce the current to 75 percent of tap value and the disk
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. With rated frequency applied,
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. See Table VI.
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. See Table VI.
TABLE VI
TAP
PICKUP PICKUP
CURRENT CURRENT
0.2 0.15-0.195 0.05 OR MORE
2.0
1.50-1.95 0.55 OR MORE
INSTALLATION
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. The outline and panel diagram is shown
in
Fig. 7.
CONNECTIONS
The internal connection diagram is shown in Fig. 3. A typical external wiring diagram is shown in
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.
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