PID Temps fluctuating a lot

[processhead]

Late to party here...
Assuming the OP has not already solved his issue, to me, it looks like an electrical noise problem.
Does the temperature fluctuate only when the element is heating?
Physically, how close is the temp probe wiring to the wiring going to the heating element?
Switched AC current to a heavy electrical load like the element could potentially induce enough noise in the probe wiring to bump the temp signal. Also, make sure the PID is grounded, if it has a ground terminal.
Physical separation between low level signal wires like temp probes and power wiring is a good wiring practice that can help avoid problems like this.

 

[NerdBrewer22]

I have had sort of the same problem and I have fixed it by replacing the probes wiring (I was using SS brainded cables included with the RTD), as I found out that the problem was the original connectors were badly wired (factory connection) and the SS braiding was shorting the rtd signal.

The inside of my panel was made using Ethernet cable (4 pairs, #24awg)

I replaced it with some FT-4 shielded cable (4 conductors, #22AWG) which is typically used for instrumentation. It include some soldering work but it should help also for interference since I chose some Shielded cable.

 

[BredStik]

Good information! Thanks

 

[GParkins]

If the wiring on the inside of the enclosure is as the OP described, cramped and messy, then the problem he's experiencing could be noise or interference related to the RTD conductors in proximity to, or even wrapped around power conductors. Maybe remove the PID from the enclosure (I know...PITA) and isolate the RTD and PID from the enclosure and all of its wiring.

 

[Nevermore]

I realize this is an old thread but its the only one i've seen that pertains to this PID and this exact issue, I am having the same temperature fluctuations. My panel is very clean, wires are shielded and protected, I do however have cheaper probes/SS leads to the panel however using the exact setup but only with my Ormon PID instead I don't get those issues. Maybe just cheaply made PIDs?

 

[postalbunny]

If you can't isolate an exact issue you could look to see if that PID has a "FILTER" setting. Not saying you shouldn't hunt down the culprit, because a 2-3deg fluctuation is pretty odd... but if that's what you've got to deal with then setting the filter to a value between 1-5 will smooth out those rapid changes.

 

[Nevermore]

I tried your suggestion but didn't have an difference I'm results. Ink bird misunderstood and suggested i offset the temperature to read true. Looks like either I try and return the pids or buy a better rtd.

 

[postalbunny]

I think i agree... i just found a similar issue which lead me to a bad rtd. One of my 3x rtd probes always seemed to be lagging or off by 3-5 deg while mashing on my new eherms setup. I took all 3 probes and put them in crushed ice water to calibrate thinking the one rtd was just off by 3-5 deg and ill program the offset (Pb for auber). In my older propane setup i only used one RTD.

What i found was that the bad pid took almost 2 minutes to catch up to the other pids... lagging quite slowly. I moved from ice water to room temp and back checking. Two of the pids stabilized in seconds, bad pid slowly came to temp over 60 seconds. I swapped PIDs and the problem followed the RTD. I also swapped cables and the issue followed the RTD.

I couldnt find much on how long they should last, or how to fix one... so i ordered a new one. The bad one is over 5 years old and saw a lot of action in a direct fire propane RIMS setup. The heat from under the mash tun may have affected it.

Yours seems to be all of them... if youve checked all the connections for loose wires then i would try ordering one good quality RTD or borrow one from someone to see if it works. If not, then it would have to be the that the pids are janky or not setup right ( i know for auber you have to out 21 for Sn to tell it you have RTD)

 

[Nevermore]

I have 3 pid and 3 probes, I've read wired them and ensures connection's were good while still getting similar results. The temperature is "off" it's just bounces around multiple times with in seconds. For example 100, 102.3, 101.1,99.5 all very quickly. Seems to steady out as it turns off a little bit. But still not perfect. I'll try experimenting with another probe off a friend tonight, I'll directly wire in to the pod to ensure the wiring is 100%.

 

[postalbunny]

Curious if you ever made any headway here... i suspected either bad probe or a grounding issue with the rest of the panel.

 

[augiedoggy]

Curious if you ever made any headway here... i suspected either bad probe or a grounding issue with the rest of the panel.

later in a couple other threads it was discovered that a number of people using the inkbird 106 model pids experience this issue but not all so I think its safe to say it either has something to do with a setting or weakness in the pid design.

I specifically remember reading about it in two other thread from multiple users having the issue because it prompted me to want to setup the inkbird I still have sitting new in a box and test it.. (which I never got around to doing since I have no purpose for it at the moment with the brucontrol setups I use now.)

 

[Brewbuzzard]

later in a couple other threads it was discovered that a number of people using the inkbird 106 model pids experience this issue but not all so I think its safe to say it either has something to do with a setting or weakness in the pid design.

I specifically remember reading about it in two other thread from multiple users having the issue because it prompted me to want to setup the inkbird I still have sitting new in a box and test it.. (which I never got around to doing since I have no purpose for it at the moment with the brucontrol setups I use now.)

Time permitting build a setup and sale it.

 

[augiedoggy]

Time permitting build a setup and sale it.

Ive got a bunch of panels now including one thats 3/4 done I was going to sell.. The issue is lack of time with starting the brewpub. Had to take the morning off of work today to go pick up a commercial stove for the kitchen.. I can see why people say "dont do it"

 

[Brewbuzzard]

Ive got a bunch of panels now including one thats 3/4 done I was going to sell.. The issue is lack of time with starting the brewpub. Had to take the morning off of work today to go pick up a commercial stove for the kitchen.. I can see why people say "dont do it"

Cool beans! I can see you have no time to spare. Best of luck to you and let us know how the opening goes.

 

[Genuine]

The Strange part about mine is that while I'm heating to mash temps, it's steady as ever. However, Once I'm at mash temp....that's when the temps start to jump around from 152.1, 153.6, 151.3, 152.0 which causes the element to turn on depending on if it dips to 149 for a quick second. Part of me wants to get an Auber to stop it. I upped the filter to 20 and it seemed to help smooth things out.

 

[Brewbuzzard]

The Strange part about mine is that while I'm heating to mash temps, it's steady as ever. However, Once I'm at mash temp....that's when the temps start to jump around from 152.1, 153.6, 151.3, 152.0 which causes the element to turn on depending on if it dips to 149 for a quick second. Part of me wants to get an Auber to stop it. I upped the filter to 20 and it seemed to help smooth things out.

I use the Auber EZboils. They work great and have a couple settings to handle issues like this.

 

[augiedoggy]

I dont know if the filtering makes the elements turn on and off any more or less or just make the display seem smoother... does the temp on the inkbird really overshoot? if not I would not be concerned but I agree it could be a minor frustration to see the temp constantly jumping.

 

[Genuine]

It will overshoot a little bit....but then again, it jumps around and it'll overshoot real quick before going down in temp. It's strange when it only does that while trying to hold mash temps, but when heating to or when i'm watching the temp out of the counterflow wort chiller, it's stable. I just can't imagine the temp fluctuating that much around 150-158 degree range.

 

[postalbunny]

I dont know if the filtering makes the elements turn on and off any more or less or just make the display seem smoother... does the temp on the inkbird really overshoot? if not I would not be concerned but I agree it could be a minor frustration to see the temp constantly jumping.

The filter on the auberin is a digital filter... it smooths out the fluctuations on the actual temp used as well as displayed. Not sure about the inkbird though.

He also stated it turns on if it dips below 149; which makes me think maybe the PID functionality isn't working very well... it shouldn't flip on at a set-point level but more off an algo to "maintain" the temp. No exp with the inkbird so I can't say much. On the Auberin you can see the "duty cycle" and tell if it's firing 20%, 50%, 75% of the time etc.

 

[augiedoggy]

The filter on the auberin is a digital filter... it smooths out the fluctuations on the actual temp used as well as displayed. Not sure about the inkbird though.

He also stated it turns on if it dips below 149; which makes me think maybe the PID functionality isn't working very well... it shouldn't flip on at a set-point level but more off an algo to "maintain" the temp. No exp with the inkbird so I can't say much. On the Auberin you can see the "duty cycle" and tell if it's firing 20%, 50%, 75% of the time etc.

the duty cycle is only for manual boil not for maintaining temps though. in pid mode they do turn on and off somewhat irratically based upon what the microprocessor has calculated would premtively work to maintain temps after its been tuned..if its not tuned well it will overshoot fluctuate more.

I have more than a couple different brands of pids and for the most part they all work the same way in pid mode. some users of the inkbird pids report rock solid readings and some report this jumping around.. I know there is a setting for "filtering" or buffering the temp reading on it according to what was shared in the other thread.

I wonder if its some sort of ground loop noise caused by the element firing? I had a similar thing with one of my brucontrol setups that would cause the temp reading to spike and jump around.