Temperature Sensor on Heat Exchanger

Thread Starter

geofreyr

Joined Jul 25, 2017
6
Hello,

I have a heat exchanger which has a wire connected to it which is merely drilled into the lead casing and connects to a PCB board into two sockets, + and -.

The heat exchanger also has a temperature switch to detect the thermal temerature and activate and deactivate accordingly.

I don't understand what the purpose of this other wire is and how it works. Please see the attached image showing the wire.

Many thanks,

Geofrey.
 

Attachments

Thread Starter

geofreyr

Joined Jul 25, 2017
6
I think it's actually called thermocouple wire. But how does it actually detect the temperature because it does not seem to have a thermometer?
 

Thread Starter

geofreyr

Joined Jul 25, 2017
6
As you can see, it simply screws onto the top of the heat exchanger. I am reading about thermocouple wires work now actually, I think that is what it is, using thermal electricity to determine the heat exchanger's temperature? thanks.
 

BR-549

Joined Sep 22, 2013
4,938
Ok.....the red and blue wires.....are dissimilar. They are connected at the circular terminal....under the shield. When that dissimilar junction heats up....it cause a small current and voltage differential at the junction. This voltage is proportional to the temp. Connect a volt meter to the wires.....and hold circular terminal over flame. Watch the voltage go up.
 

Dodgydave

Joined Jun 22, 2012
9,940
Connect a Voltmeter on Millivolts, and hold the Eye terminal in a flame, the red and blue wires will give out a DC supply as the temperature rises, probably 2- 100 mV.
 

Thread Starter

geofreyr

Joined Jul 25, 2017
6
Why does it have both a thermocouple wire and a thermometer switch, would this be used as a safety precaution in case the switch fails the thermocouple has been programmed on the PCB to turn off the power?
 
Top