Power Soak 37179 PS-275 Service Manual - Manual (Page 28)

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6.6 Contactor
A mechanical contactor is used to disconnect the high voltage electrical supply from the
Triacs when the UPM detects a problem with the pump motor or wash tank heater. The
contactor is located on the left side of the mounting plate in the control enclosure. The
contactor is defective if there is 20vac-28vac across the coil and the contactor does not
pull the center button into the core. When the center button is pulled into the core and
there is input voltage across terminals L1 and L2 (also L1-L3 and L2-L3, if three phase),
but no voltage across terminals T1 and T2 (also T1-T3 and T2-T3, if three phase), the
contactor is defective.
6.7 Load Sensor
The high voltage wire leading to the heater and motor along with the coil wire for the
contactor have been placed through the center of a load sensor. This device senses
the amperage on the electrical supply to the components in order to detect an overload
situation. In order for the sensor to function properly the smaller wire from the contactor
coil must be wrapped three times through the center of the load sensor body. A plastic
“zip tie” is tied around the high voltage wire to keep the senor from sliding down the high
voltage wire.
The contactor is connected to high voltage electricity. The
power to the machine must be turned off at the circuit breaker
in the wall mounted enclosure when working on the contactor.
Failure to turn off the power will result in serious injury and
possibly death.
Load Sensor
High Voltage Wire
Wire tie to keep
the sensor from
sliding down the
high voltage wire
Contactor wire must be
wrapped 3 loops
through the center of
the load sensor for
proper operation.
Contactor