temperature bouncing

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1ds19
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temperature bouncing

Post by 1ds19 »

Hello,

I've been experiencing some bouncing temperatures with my BCS 460. I have four probes purchased from ebrewsupply (I believe they are identical to those sold through brewershardware). I've used the coefficients provided by brewershardware to calibrate these sensors. This phenomenon occurs constantly throughout a brew session or at room temps. Any ideas to reduce the bouncing of these readings, and is this normal? Thanks in advance.

Drew
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Bayoujeeper
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Re: temperature bouncing

Post by Bayoujeeper »

Is the BCS grounded to the panel ground?
JonW
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Re: temperature bouncing

Post by JonW »

You need to ground your BCS. Run a jumper wire from one of the BCS GND terminals to an earth ground (AC ground).
1ds19
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Re: temperature bouncing

Post by 1ds19 »

Thanks JonW, Bayoujeeper, this did the trick.
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AndrewsBrewing
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Re: temperature bouncing

Post by AndrewsBrewing »

I've been using my 462 for over a year now. The temps just started jumping around for the first time today. I have all the grounds setup as previously advised. I'm running 4.0.0

Any advice would be greatly appreciated.

Eric
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Re: temperature bouncing

Post by JonW »

Is it jumping just like shown in the logs in this thread? Are all temp probes doing it? Are they pretty much doing it in sync with each other?

If the answer to the above is yes, then I hate to say it, but check the wiring. I do not recall ever seeing this issue that was not a result of grounding.
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AndrewsBrewing
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Re: temperature bouncing

Post by AndrewsBrewing »

Hello Jon,

Yes they are all jumping and not in sync with each other.

Image

I have checked all the grounds and they are good. For instance, I measured the resistance of touching the two probes together on my meter. And the measurement was exactly the same from the ground pin (on the plug that gets plugged into a receptacle) to the ground on the BCS. Checked all wires to see if any were loose.

Love the BCS. What is next, Jon?

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oakbarn
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Re: temperature bouncing

Post by oakbarn »

This happened to me as well. :o One day I had the Temps jumping like yours and I was not sure of the cause but I assumed it was "wiring" or EMI. I had done nothing different that I knew of. :)

I re did all my temperature probe wiring . I used a single 18 awg foil shielded twisted pair to connect to an M12 Disconnect inside a metal box. I run M12 Patch cables to my Probes. I ran the cables from the BCS to a metal box through 3/4 inch metal conduit and was careful to cross any AC wires at a 90 degrees. I kept the conduit at least 4 feet (the best I could do) away from any wires running the same as the conduit. The "ground" for each probe was a "home run" back to the BCS Ground. The conduit or the drain wires were not grounded. The metal box was not grounded. The M12 in the metal box are not "grounded" to the box.

This was surely overkill but I did not know what was causing the issue. It works fine now. There are no splices or connections other than the M12 disconnects and all grounds were run individually back to a "ground" bus connected to the BCS ground. The M12 Disconnect box has nothing but the M12s and the cables from the BCS.
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Re: temperature bouncing

Post by JonW »

My guess would be the same as Oakbarn. Looks to me like it might be interference from the high voltage wires.

Are your temp probes running alongside any of the HV wires?
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AndrewsBrewing
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Re: temperature bouncing

Post by AndrewsBrewing »

Mystery solved.

I have a wall wort on our board that powers some LED lights on the switches. That wall wort failed and was emitting noise.

Thank you for your help though, Jon and Oakbarn

Eric
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