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Temp probes go Haywire!!

Posted: Wed Jul 04, 2012 9:47 am
by dtfeld
I have multiple ECC tempo probes installed. They are calibrated and work most of the time, but every so often, the temp reading go haywire. I usually push gently on the probe where the wire exits the SS probe and they settle down again nicely. It looks like EMI to me but have not been able to link it to anything in the system (pumps, elements ect.) as this happens in a steady state condition (heaters on, pumps on) after 20-30 minutes and erratically at that. This happens in both a SS HLT and my rubbermaid plastic cooler, so I'm thinking its not a grounding issue

Any ideas?

Re: Temp probes go Haywire!!

Posted: Wed Jul 04, 2012 10:34 am
by JonW
Do you have a jumper going from earth ground to the BCS 5V ground? Several of us have had sporadic temp fluctuation issues that were solved by placing a jumper between the AC and DC grounds.

Re: Temp probes go Haywire!!

Posted: Wed Jul 04, 2012 11:11 am
by dtfeld
I have a BCS-462...there are 3 separate GND pins, I have only the 2 of the three grounded. Do I need to ground all three as I'm not using all the Temp inputs and didn't ground the ones associated with the unused temp inputs.

Re: Temp probes go Haywire!!

Posted: Wed Jul 04, 2012 11:27 am
by JonW
They're all common ground. Are you saying you have a jumper wire going from two of them already to an earth ground?

Re: Temp probes go Haywire!!

Posted: Wed Jul 04, 2012 12:37 pm
by dtfeld
Yes, I had only two connected. I just reran a ground from the AC ground bus to all three GND pins, running a test now...seems to have addressed it.

I'll have to do a brew session to confirm, I've thought I've solved this before... :D

Re: Temp probes go Haywire!!

Posted: Wed Jul 04, 2012 1:32 pm
by dtfeld
Currious...maybe ECC can answer...

Why 3 separate GND pins? Are they connected (common ground) or are they separate and if so why?

Re: Temp probes go Haywire!!

Posted: Wed Jul 04, 2012 2:37 pm
by JonW
They are common, that's why I was asking if you had already done two of them. Seems only one should be fine.

Pretty sure the multiple ones are just so you have multiple connection points without having to cram wires in or use a junction block.

Re: Temp probes go Haywire!!

Posted: Sat Jul 07, 2012 2:20 pm
by dtfeld
I jumpered all 3 to the AC ground and the problem has stopped...who knew? Is it possible that having two grounded as opposed to one or all three created a ground loop?

Re: Temp probes go Haywire!!

Posted: Sat Jul 07, 2012 8:48 pm
by ECC
The are all common (you can verify with a continuity test), we just provide multiple pins for convenience.

Re: Temp probes go Haywire!!

Posted: Mon Jul 09, 2012 3:12 pm
by dtfeld
Thanks for the clarification...