Having trouble with my PID/thermocouple

Karmaru

Karmaru

Joined
Feb 6, 2013
Messages
17
Hoping someone here can shed some light on what I screwed up. I bought a thermocouple, thermocouple sheath and pid controller off ebay a while ago to monitor the temp inside my LP gas forge. I got everything hooked up and installed in the forge and the unit seemed to be functioning fine. I could see the unit registering the correct temp up to about 2000 degrees F then it would display "HH" (which from what I've read is the upper limit of the PID").

Anyhoo...I screwed up and got the rear on the thermocouple too close to the dragons breath off the front of the forge and melted the mini connector. So I ordered a new mini connector and replaced the old one. Now, the unit displays "HH" just past 1300 degrees F and stays there until the thermocouple cools below that temp. I know I didn't modify any settings on the PID and I have verified that the units is set to Fahrenheit...I even switched the setting to Celsius to verify it was going to "HH" at 700 degrees C.

Any idea what I screwed up that my unit won't show temps above 1300 F anymore?
 
Double check that the connector or the wires aren't backwards. A reversal would make the reading off. The wires from the TC to the PID and any connectors are polarized. The wires also need to be Type K wire.
 
Much thanks for the quick reply Stacy. I'll give it a look as soon as I can get in the shop.
 
Still a no go with my PID. I tried reversing the mini connector and that didn't work. Also tried reversing the connections to the PID. The unit still ramps to 1300 F and registers "HH".
 
Karmaru said:
Hoping someone here can shed some light on what I screwed up. I bought a thermocouple, thermocouple sheath and pid controller off ebay a while ago to monitor the temp inside my LP gas forge. I got everything hooked up and installed in the forge and the unit seemed to be functioning fine. I could see the unit registering the correct temp up to about 2000 degrees F then it would display "HH" (which from what I've read is the upper limit of the PID").

Anyhoo...I screwed up and got the rear on the thermocouple too close to the dragons breath off the front of the forge and melted the mini connector. So I ordered a new mini connector and replaced the old one. Now, the unit displays "HH" just past 1300 degrees F and stays there until the thermocouple cools below that temp. I know I didn't modify any settings on the PID and I have verified that the units is set to Fahrenheit...I even switched the setting to Celsius to verify it was going to "HH" at 700 degrees C.

Any idea what I screwed up that my unit won't show temps above 1300 F anymore?
Click to expand...

Its strange that 1300 degrees = 2372 degrees f. Id double check the f and c settings.
 
I'm not an expert on PID's, but just some basic fault finding logic...

If you didn't do anything to the PID and the F/C is definitely correct, I'd be checking the TC and the TC wires... Sounds like the TC could be reaching it's maximum limit at 1300 or it's reading incorrectly. You may have damaged more than the mini connector?
I'd either try another TC or check the forge temp to see if it's actually at 1300 or the TC is reading low?
 
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