User Guide

Troubleshooting 29
Doc 01-G0547
Rev D
3B.
If there is power, then check for it at the transformer primary terminals. If there is voltage at the
switch and none at the transformer, then you probably have a bad power disconnect and it should
be replaced.
3C.
If 3A and 3B check out O.K., then manually disconnect the operator from the gate. Very
carefully, using a screwdriver with an insulated handle, press down on the open side of the
contactor. Then, do the same to the close side of the contactor. Then, do the same to the close
side of the contactor. Did the operator run in both directions? If it did, the problem may be in the
low voltage control circuit, if it did not, then the problem is either in the contactor or the motor.
NOTE: Some motors have the overload built into the motor itself, while other units have a
separate overload in the controller.
3D.
If the contactor is suspected to be causing the problem, first carefully check all wiring connections
at the contacts. DISCONNECT POWER! USING A V.O.M. take continuity readings across the
contacts of the contactor. Place one probe on 1 and the other on 2. You should get NO
continuity, now press down on the contactor, you should get a continuity reading. Repeat this on
all the of the contactor’s contact points.
Figure 27
4. Low Voltage Circuit
4A.
The first thing to check is the circuit breaker.
4B.
The secondary voltage must be between 22 and 30 vac. This voltage can be checked at the
circuit board at terminals J1-3 & J1-11.
4C.
The contactor coils receive 24 vac. to activate the motor in either the open or close direction.
There are two contactor coils (one for open and one for close).
4D.
The limit switches are S.P.D.T. (single pole, double throw). These limit switches are what tells the
operator to shut off at either the full open or full close position.