Part 20 Description - 5100 Series
Brick Core Sensor (Thermocouple)
The brick core thermocouples sense the temperature of the brick core. They are connected to the core sensor terminals on the processor control board. Location 110 (L110) and Location 111 (L111) indicate the current brick core temperature as sensed by the brick core thermocouples.
NOTE: On the 5130 and 5140 brick core A is the lower core. Models 5130 and 5140 have a Core B, which is the upper core. The model 5120 has only one core and it is referred to as Core A.
To test these K-type thermocouples, read mV 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.
NOTE: 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.
Also on systems with multiple core sensors, the upper core sensor MUST be connected to the top two terminals and the lower core sensor MUST be connected to the bottom two terminals. Refer to the Internal Low Voltage Wiring Diagram for details.
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Thermocouple Placement in the rows of the Brick Core |
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|---|---|
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5120 |
Row 6 |
|
5130 |
Rows 5 and 9 |
|
5140 |
Rows 6 and 12 |
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