Issue with Inkbird ITC308S - anyone else had this?

[emerson909]

Not tried that but it would be a pain in the arse to test, it occurs at random so you’d have to sit there holding the probe for a bit

 

[The-Engineer-That-Brews]

Oh - it doesn't happen every time the relay switches?

 

[emerson909]

No, the fault seems to change the measured temperature to cause the relay to switch, rather than the relay switching affecting the reading

 

[Bocker Wright]

Does it behave reliably like that whenever you're holding the sensor, even when it's connected up to a proper load (heater and/or refrigerator) ?

Well yesterday when I manually heated and cooled, alarms worked and everything fine... but I've just witnessed the temp suddenly rise and switch on and off the cooling without anything plugged in either socket on the inkbird. So it seems its capable of doing it without anything plugged in now.

 

[The-Engineer-That-Brews]

I've just witnessed the temp suddenly rise and switch on and off the cooling without anything plugged in either socket on the inkbird

OK, that would seem to rule our power-line transients being the issue then :-)

 

[The-Engineer-That-Brews]

the fault seems to change the measured temperature to cause the relay to switch, rather than the relay switching affecting the reading

Interesting... is there any particular reason you say that? On the video @Bocker Wright posted it looked to be simultaneous - but I'll go back and have another look now

 

[Bocker Wright]

Interesting... is there any particular reason you say that? On the video @Bocker Wright posted it looked to be simultaneous - but I'll go back and have another look now

I'm not sure to be honest whether it's simultaneous or one after the other. Its very fast if it isn't simultaneous

 

[The-Engineer-That-Brews]

OK are these units meant to be just dumb thermostats, or do they have PID functionality? I imagine on your video the upper reading is the current process value (PV) and the lower one is the set point (SP) - if so, the temperature is indeed a little low (20.4 versus the desired 20.5) so if the controller has a PID function then it could be the error integrator giving the process a 'kick' of heat to lift the temp up to 20.5 - which is in fact what happens...?

 

[emerson909]

No not PID controllers, just discrete on/off. There’s definitely no integral time to adjust anyway.

I have a video where the PV goes from 21, to 20 and kicks heating on then back to 21.5 within a second, there’s just no way the actual temp can change that fast so must be electrical fault.

 

[The-Engineer-That-Brews]

OK well good luck with it!

 

[simonjohnperkins56]

I’ve had an ink bird 308 it lasted 7 months and burnt out now have a mangrove jack dual temperature controller hope I have better luck with this.

 

[chrisb8]

Hi Chrisb8 how did it turn out? I'm having exactly the same issue, it's only been out the box 4 days. Temp suddenly jumps a degree or so, switches on the fridge for a split second and straight back off while the temp drops back down again.

Hi and apologies for the delay in getting back to your post, I haven't been on the forum for a while. In answer to your question, I have had no further luck with this - a replacement inkbird unit does exactly the same thing but just not as often as the original one so I have just got used to it happening.

It is interesting to read the posts by @The-Engineer-That-Brews regarding electrical interference as I often wondered if this was the case - could the electrical wiring nearby or under the floor have an effect? I'm only making a guess...

 

[Bocker Wright]

Hi and apologies for the delay in getting back to your post, I haven't been on the forum for a while. In answer to your question, I have had no further luck with this - a replacement inkbird unit does exactly the same thing but just not as often as the original one so I have just got used to it happening.

It is interesting to read the posts by @The-Engineer-That-Brews regarding electrical interference as I often wondered if this was the case - could the electrical wiring nearby or under the floor have an effect? I'm only making a guess...

Hi chrisb8. I exchanged it for a stc 1000 mangrove jacks unit in the end. I messaged a couple of topics on here trying to find an answer but I just thought side it, swap it. There's been others with the same problem we're not the only ones.

 

[chrisb8]

Hi chrisb8. I exchanged it for a stc 1000 mangrove jacks unit in the end. I messaged a couple of topics on here trying to find an answer but I just thought side it, swap it. There's been others with the same problem we're not the only ones.

No worries. It's a shame because it's such a simple and useful bit of kit but if a temperature controller can't read a steady temperature then it is really a serious flaw...

 

[peebee]

I have asked Inkbird to have a look at this thread.

@Inkbird never did come back to answer concerns about the ITC-308 ...

... It's a shame because it's such a simple and useful bit of kit but if a temperature controller can't read a steady temperature then it is really a serious flaw...

So, I think the conclusion has to be:

The ITC-308 has a serious design fault that may seriously damage any fridge or freezer a ITC-308 has control of. AVOID USING AN ITC-308 TO CONTROL KEGERATORS AND KEEZERS!!!

Meanwhile, my keezer is still controlled by an ITC-308 because I still haven't fitted the ITC-1000 which I hope wont share the same issue. I have now seen the issue happening for myself (the temperature suddenly skips up a degree or two before returning to its previous reading, but not before turning on the freezer's compressor and quickly turning it off again as the temperature display falls back again).

I'm developing a workaround for the time-being based on why I don't seem as badly affected by it as some. In the manual you will find:

When the measured temperature PV >= TS (temperature set value) + CD (cooling differential value), system enters refrigeration status, the cool indicator light will on, and refrigeration relay starts to work; when the cool indicator light is flickering, it means the refrigeration equipment is under compressor delay protection status.

The smaller you set the CD value, the more frequently you can expect to hear the fault. I'd set mine to 1.2, but the pulsing on-off of the compressor wasn't stopped completely. Perhaps 1.5 or 2.0 might work? The aim is to have CD larger than the erroneous skips so the compressor is never pulsed on-off. (EDIT! Oops, logic error! When the freezer warms into the "error zone" the on-off pulsing begins again. But at least I get a short period of no trouble in place of just constant trouble).

The "compressor delay protection" will not help. The delay timer starts when the device is turned on, or from when it last turned off the compressor. So when the next fault occurs, the delay timer has already expired and so the compressor will start even if only for a fraction of a second.

 

[-Bezza-]

I had the email address for someone at Inkbird as I had tested a new product for them and they were helping with a software bug (very helpful) so I have dropped them an email with a link to this thread to see if they can help.

 

[Inkbird]

Hello,
We are not very active here, so sorry for not giving you a timely reply. We provide more contact information on the personal introduction page. If you have any questions, you can always contact the seller support of the buying platform, our company email([email protected]), or FB team support, we will try our best to help you solve it and give you one satisfactory answer.
The problem of reading jumps do not seem to be equipment problems, but may be caused by the position of the probe. Could you kindly tell us more details and help check it? @chrisb8
@peebee @Bocker Wright PM sent and please check. Please be assured that we will make things easier for you and will do everything we can to prevent you from bearing any kind of loss.
Regards

 

[peebee]

Hello,
We are not very active here, so sorry for not giving you a timely reply. We provide more contact information on the personal introduction page. If you have any questions, you can always contact the seller support of the buying platform, our company email([email protected]), or FB team support, we will try our best to help you solve it and give you one satisfactory answer.
The problem of reading jumps do not seem to be equipment problems, but may be caused by the position of the probe. Could you kindly tell us more details and help check it? @chrisb8
@peebee @Bocker Wright PM sent and please check. Please be assured that we will make things easier for you and will do everything we can to prevent you from bearing any kind of loss.
Regards

Thank you for the reply.

I think blaming the position of the probe as possibly creating the problem is clutching at straws. Several people are reporting the issue, are we all making the same "mistake" placing the probe? My own probe is in a PET bottle stoppered with cotton-wool to dampen the temperature effect of opening the freezer. And all reports are of a sudden (instantaneous) shift in displayed temperature of 1 or 2 degrees, followed by a steadier (several seconds) return to the original temperature. These are the antics of a software glitch in the equipment, not an issue with the environment the equipment is in.

I have two ITC-308s of different ages (the newer one replaced a failed third, older out of warranty, device) and both act the same (same issue). But interestingly, when monitoring temperature of a fermenter (i.e. probe not within a fridge/freezer; controls an external cooling device) I have not witnessed the issue?

 

[chopps]

it’s not in a bottle of liquid is it?

 

[peebee]

it’s not in a bottle of liquid is it?

Na. Liquid would probably have an excessive dampening effect. But in air some precaution is necessary to avoid the probe touching the bottle which might negate the dampening effect?