Alarm Message Cause Corrective Action Dryer Status
Limit switch may be out of
position. Re-adjust the
switch to make sure it trips
when it is at the high
position, and it does not
touch the cam when it is at
the low position.
The limit switch on the
valve may not have
been wired correctly.
The valve has made
enough rotations and
the correct position of
the valve was not
detected.

VALVE MTR

Valve motor or not
connected to 120V at
PLC/Circuit
The switch is indicating the
incorrect desiccant tank is in
regeneration. Check the
wiring of the switch against
the wiring diagram. Make
sure all the wire connections
are tight.
Limit switch may be faulty.
Replace the switch and
make sure the wires are
connected correctly.
- Dryer Shuts down:
- Process blower OFF.
- Process heaters OFF.
- Regen heaters OFF.
- Alarm light is ON
- Alarm horn is ON.
6-2 Determining Temperature Controller Errors or Sensor Errors

Using a Thermocouple

If the controller displays a temperature that is close to room temperature (70ºF/21ºC) when
you short-circuit controller input terminals, the controller is normal and the sensor is probably
broken, short-circuited, or incorrectly wired.
Other service problems or questions can be answered by contacting the Service
Department.
Dehumidifying Dryers 6Troubleshooting 44 of 53