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JOHNSON CONTROLS
37
FORM 130.13-NOM8 (1021)
Moisture Sensor Installation (For Use With
Drip Pan - No Drain Hose Connection)
The moisture sensor assembly is installed at the low
point in the dual-sloped pan. The assembly clips over
the side of the pan with the body of the sensor inside
the pan. Two electrical contacts on the bottom of the
sensor (against the drip pan wall) detect water.
When sensor is at the minimum position (sensor body
touching the floor of the pan), it will measure ~ 0.25”
of water. Switch will trip when the water level reaches
a point even with the electrical contacts. Sensitivity
may be adjusted by sliding the sensor assembly up or
down along the side of the pan if necessary.
The sensor must be powered with 24VAC for testing
and operation (RED – 24VAC, BLK – 24V COM).
Test switch by measuring continuity between PUR
and GRY wires when the sensor is dry. Continue
measuring for continuity between PUR and GRY
wires lifting the floating switch and observing an open
circuit (loss of continuity).
The sensor also has a set of normally open contacts
which will have the opposite behavior (between WHT
and GRY wires). Test switch sensitivity by filling pan
and confirm signal changes when water reaches
height of contacts.
Moisture sensor installed