| Symptom |
Possible Cause or Solution |
| Tripped Light On |
Whenever the pump is off as a result of Subtrol-Plus protective function, the red tripped light is on. A steady light indicates the Subtrol-Plus will automatically allow the pump to restart as described, and a flashing light indicates repeated trips, requiring manual reset before the pump can be restarted. Any other red light operation indicates a faulty receiver. One-half voltage on 460 V will cause tripped light on |
| Control Circuit Fuse Blows |
With power turned off, check for shorted contactor coil or a grounded control circuit lead. The coil resistance should be at least 10 ohms and the circuit resistance to panel frame over 1 megohm. A standard or delay-type 2 amp fuse should be used. |
| Contactor will Not Close |
If proper voltage is at the control coil terminals when controls are operated to turn the pump on, but
the contactor does not close, turn off power and replace the coil. If there is no voltage at the coil,
trace the control circuit to determine if the fault is in the Subtrol-Plus receiver, fuse, wiring, or panel
operating switches. This tracing can be done by first connecting a voltmeter at the coil terminals,
and then moving the meter connections step by step along each circuit to the power source, to
determine at which component the voltage is lost.
With the Subtrol-Plus receiver powered up, with all leads disconnected from the control terminals
and with an ohmmeter set at RX10, measure the resistance between the control terminals. It should
measure 100 to 400 ohms. Depress and hold in the reset button. The resistance between the
control terminals should measure close to infinity. |
| Contactor Hums of Chatters |
Check that coil voltage is within 10% of rated voltage. If voltage is correct and matches line voltage,
turn off power and remove the contactor magnetic assembly and check for wear, corrosion, and dirt.
If voltage is erratic or lower than line voltage, trace the control circuit for faults similar to the previous
item, but looking for a major drop in voltage rather than its complete loss. |
| Contactor Opens When Start Switch is Released |
Check that the small interlocks switch on the side of the contactor closes when the contactor
closes. If the switch or circuit is open, the contactor will not stay closed when the selector switch
is in HAND position. |
| Contactor Closes But Motor Doesn't Run |
Turn off power. Check the contactor contacts for dirt, corrosion, and proper closing when the contactor is closed by hand. |
| Signal Circuit Terminals Do Not Energize |
With the Subtrol-Plus receiver powered up and all leads disconnected from the signal
terminals, with an 0hmmeter set at RX10, measure the resistance between the signal
terminals. Resistance should measure close to infinite. Depress and hold in the reset button.
The resistance between the signal terminals should measure 100 to 400 ohms. |