I.L. 17403
Page 6
Effective 9/04
In all cases, control power to terminals 3-P-E-C must be
from the same phase. An interposing relay must be used
wherever the controlling signal to 3 or P would be a differ-
ent voltage, frequency, or phase than the voltage supplied
to E and C. See
TWO-WIRE CONTROL
.
If a triac output Programmable Logic Controller (PLC) is
being used for control on a Model D or earlier, it will be
necessary to know the required triac latching and leakage
currents. If the latching current is greater than 6 milliam-
peres, it will be necessary to mount loading resistors be-
tween the P and/or 3 terminal and the C terminal or the
contactor may fail to remain sealed. The value of the resis-
tor is determined by dividing the control voltage (120V)
by the latching current supplied by the PLC manufacturer.
The power level of the calculated resistor is determined
by dividing the square of the control voltage (120
2
) by the
resistance value. The resistor should have a power rating
that is twice the calculated power level. If the leakage cur-
rent exceeds 0.2 milliamperes, it will be necessary to add
a resistor-divider network or the contactor may fail to
open. A 3 milliampere leakage current will require a 3K
(6 watt) resistor in series with the P terminal and a 1K (2
watt) resistor connected from the P to the C terminal.
Consult with your local Culter-Hammer sales office re-
garding other leakage current values. If
both
excessive
latching and leakage currents exist, it may be necessary
to use an interposing relay.
Fig. 5 Conventional Holding Circuit, Three-Wire
Fig. 6 Conventional Holding Circuit, Three-Wire,
with IMPACC
THREE-WIRE CONTROL WITH CONVENTIONAL
HOLDING CIRCUIT
Wire as shown in Figure 5 (without communications) or
Figure 6 (with communications) using an external auxiliary
contact (Ma) as the holding circuit interlock between con-
trol circuit terminals 2 and 3. Add a jumper of #16 or #18
AWG stranded wire between control terminals 3 and P.
Keep strip length to not greater than 1/4 inch.
Be sure
to have jumper clear the power terminal.
Attach and
route twisted pair or shielded wires to a remote reset/trip
indicator module where provided.
Without Communications
Wire control devices in the same manner as conventional
motor controllers. Add the jumper.
With Communications
Attach a WPONI communications module and connect
it to the INCOM network daisy-chain fashion as shown
in Figures 4 and 6.
When wired as shown in Figure 6, the motor cannot be
started via the IMPACC system, but only stopped and
the starter reset.
5300C76E
5300C76F
