Troubleshooting
32
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.
Using a Platinum Resistance Thermometer
If the controller displays a temperature of about 0.0°C (32ºF) when you insert a 100-ohm resistor between
terminals
A
and
–B
of the controller, and you short-circuit controller terminals
+B
and
–B
, the controller is normal and the sensor is probably broken, short-circuited, or incorrectly wired.
