Pt 100 RTD Erratic temperature

[searly333]

I tried to put a brew down this arvo and my temperature sensor is behaving erratically. I was getting swings of up to 15 degrees within a couple of seconds in 34l of water. Needless to say the PID controller didn't know if it was Arthur or Marthur and had no chance of controlling the temperature. I pulled the probe apart and gave it a good workout with a hair dryer in case there was some moisture in there that was the problem but it didn't seem to help. I went through all the settings to see if maybe something had gone haywire but nothing had.

Just wondering if anyone has had similar issues or might know whats going on?

 

[billygoat]

Have you checked the connections where the three RTD wires terminate to the controller?
Play around with them, give them a wiggle and see what happens. Check any other connections on the RTD wires.

 

[newguy]

Have you checked the connections where the three RTD wires terminate to the controller? Play around with them, give them a wiggle and see what happens. Check any other connections on the RTD wires.

+1

Classic symptom of loose or broken wires. If re-seating the wires doesn't help, there is likely a broken wire in the cable somewhere.

 

[dmac80]

As Newguy has said,
RTD's are prone to bad connections. If tightening connections doesn't fix the issue, sometimes cutting any crimp lugs off and replacing them with new ones can help.

Cheers
Dan

Edit:Typo

 

[searly333]

On closer inspection this morning have found a bit of crushed wiring. Hopefully after thats fixed it should be business as usual.

Thanks guys

 

[searly333]

Job done.

Shortened the wires and resoldered.

Approaching strike temp now.

Cheers :beer:

 

[searly333]

Or so I thought...

Anyone know somewhere in newcastle to get a replacement rtd?

Need to brew today

 

[dmac80]

I have an RTD i could lend you, where in Maitland are you? Does the diameter matter?

Cheers

P.S. Send me a PM if you are interested

 

[searly333]

Is that dan mcnally?

Its searly