GSI Outdoors PNEG-630 - Manual (Page 107)

Portable Dryer Troubleshooting
106
Plenum Sensor
Procedure for Locating, Testing and Replacing
a Defective Plenum Temperature Sensor
Symptoms of a bad sensor may include:
Temperature readings that are not consistent with the ambient outside temperature or
with a verified plenum temperature that has been taken with a thermometer.
Erratic plenum display readings.
Plenum temp open or plenum temp short.
Troubleshooting:
1. The process of checking the sensor is similar to that of the grain sensors, but you
only have one sensor to check.
2. The actual plenum sensor is located in the plenum just inside the rear access door
to the right. (Facing the rear of the dryer)(See picture on next page)
3. Start at the CPU/Display board, it is located on the door of the lower box.(See below)
4. The wires from the sensor (which are butt connected at the sensor) go through a
conduit in the plenum section of the dryer.(See next page) That conduit terminates at
a white plastic 4"x4" junction box. This box is located on the front of the dryer to the left
of the fan/heater. (Facing the front of the dryer.) From that point to the CPU/Display board.
5. The wires are connected to terminals J7-12 (white wire) and J7-13 (black wire) on the
back of the Cpu/Display board.(see picture below)
6. Unhook those wires
7. What you will be checking is resistance in relationship to a known temperature.
(See resistance/temperature chart on previous page.)
8. With a ohm meter, set your scale to 20k (if it’s not a autorange model).
9. Place one probe of your meter on one wire going out to the sensor and the other
probe to the other wire.
10. The meter should read close to the resistance/temperature chart on previous page.
11. Assuming you have checked the wiring from the CPU/Display board to the sensor and
it is OK. But the resistance is not close to what is on the chart. You probably have a bad
plenum bolt sensor.
Plenum Sensor
Connected to
J7-12 & J7-13
Plenum Bolt
Sensor
(Part No. HF-7236)
Back of Door on Lower Box
CPU/Display Board