Part 19 Description - 2100 Series
Brick Core Sensor (Thermocouple)
The brick core thermocouple senses the temperature of the brick core. It is connected to the core thermocouple terminals on the processor control board. Location 110 (L110) indicates the current brick core temperature as sensed by the brick core thermocouple.
To test this K-type thermocouple, read mV (millivolts) DC across the red and yellow thermocouple wires. Compare the mV DC reading to the K-Type Thermocouple Chart. To check for a short to ground, disconnect the thermocouple wires from the processor control board. The thermocouple leads must be greater than 20 meg ohms to ground when disconnected. If not, find and remove the short. ALso, a weak or failing thermocouple can be found by comparing the mVDC reading with the sensor connected to the control board to the reading with it disconnected. If the readings differ by more than 0.5mVDC, the sensor is weak and should be replaced.
NOTES:
- The polarity of the thermocouple is extremely important!
- Make sure the red thermocouple wire (negative potential) is in the "R" terminal and the yellow wire (positive potential) is in the "Y" terminal on the lower two terminal block positions of the processor control board.
- Refer to the Low Voltage Wiring Diagram for details.
