ITC-308 troubles!

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PeeBee
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ITC-308 troubles!

Post by PeeBee » Wed Jul 28, 2021 10:16 am

I've hi-jacked my own thread!

Just put that right with this link TILT troubles!. There will be folk who might be interested in issues with a "favourite" temperature controller, but no interest in a TILT.

Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... V1bWc/view

chris2012
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Re: ITC-308 troubles!

Post by chris2012 » Wed Jul 28, 2021 12:45 pm

What are the main issues out of interest? I just had a look at your link, I've never had mine rapidly cycle the fridge that I've noticed. I think I use around a 5 min compressor delay and 0.5C for heating/cooling values. I've used the fridge at a range of temps from 20C with a heater, to -1.5C with just cooling.

Reading their description of compressor delay, as I understand it does:

Process Value > Temperature set value + Cooling differential value
* Wait for timer to be more than Compressor Delay
* Start timer
* Start refrigeration

Process Value <= Temperature set value
* "the cool indicator lamp will off, and the refrigeration relay stops working"
* "Delay time will be calculated right after the moment refrigeration stop"

Does this mean you could still get: compressor on for 1 minute, waits 4 minutes, compressor on for say 1 minute etc.? (however wouldn't that only happen if the fridge cooled the large thermal mass of the liquid pretty fast, and then it also warmed up fast?)

A while ago I tried OCR'ing the output of it, it seemed to keep within around ~1C I think from my graph. ( https://www.anfractuosity.com/projects/ ... kbird-308/ ) that was just with a towel around the fermenter too, rather than a fridge.

I'm thinking of possibly playing with a PLC soon, to control my ferm temps, if I can find a nice used one.

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Re: ITC-308 troubles!

Post by guypettigrew » Wed Jul 28, 2021 1:57 pm

Firstly, thanks PeeBee for the link to the Homebrew site with the thread about problems with Inkbird 308s. Interesting reading.

My ITC 308 has been controlling the temperature in my beer cupboard for the last 4 1/2 months without showing the sudden spiking problems talked about in the HB thread. I spend quite a lot of time in my brewery (garage) and I'm sure I would have noticed if it was spiking.

The 308 is set to 11°C, with the compressor for the cool plate set to come on if the temperature goes above 12°C and the tubular heater coming on if the temperature goes below 9.5°C. This set temperature (11°C) is higher than the set temperature reported by people having a problem with the 308. Although the wonderful video by Bocker Wright did show it spiking at 20+°C.

The probe is in free air in the cupboard, which is relatively large in comparison with a 'fridge. It's 0.18 cubic meters, or 180 Litres, to put it another way.

The compressor delay is set to 10 minutes. This means the compressor can't come on more often than every 10 minutes. When the set temperature is reached and the compressor has been turned off the 308 begins the 10 minute countdown.

If I open the cupboard as soon as the compressor has turned off the temperature will shoot up. Today it is easily reaching 14°C as warm air rushes in. The cooling light on the 308 blinks, but the compressor isn't turned on, because the 10 minutes hasn't expired. Once the cupboard is closed again the temperature will drop because the cooling plate is still cold and the three kegs in there are also cold. If the temperature drops to below 12°C before the 10 minutes delay is up then the light goes out and the compressor won't come on.

So, no problems so far with the 308.

But I suppose the most useful question to get an answer to is the one you posed PeeBee. Does it matter if the compressor flicks on and off? Is it just an urban myth, based on compressors from decades ago, that this activity will destroy them.

We need a compressor expert to advise.

Guy

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Re: ITC-308 troubles!

Post by PeeBee » Wed Jul 28, 2021 2:18 pm

chris2012 wrote:
Wed Jul 28, 2021 12:45 pm
What are the main issues out of interest? ...
My understanding is the compressor, once started, should run for at least n minutes, and once stopped shouldn't run again for n minutes. The ITC-308 will do neither of those things. But that is by-the-way, because the real issue is the failure to maintain a steady temperature reading.

But for you with a 0.5C "dead zone" (which Inkbird will say is way too small, but don't say why you can set it), if a spike of 3C occurs it will switch on the cooling compressor even if the actual temperature is 2.5C below the set temperature. And as the ITC-308 returns quickly to indicating the correct temperature (probably in less than 3 seconds) it turns the compressor off again.

Your monitoring probably wont even notice this blip. Everything looks just rosy. What its doing to the longevity of the compressor is another matter.


My work-around is to have a dead zone larger than the majority of erroneous spikes; i.e. >3C (not 0.5C!) in the above example.

A better work-around is: Don't use ITC-308s! They are cr&p!

Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... V1bWc/view

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Re: ITC-308 troubles!

Post by chris2012 » Wed Jul 28, 2021 2:27 pm

Thanks for the reply. What might be interesting if I monitored the actual compressor coming on, via power usage, which would spot spikes I guess.

Have you heard of this - https://www.fermentrack.com/ I was mentioned that recently, which sounds interesting.

I'm just looking at these kind of things at the moment - https://www.lamonde.com/products/progra ... dd2-d.html but need to do more reading about PLCs in general.

Edit: Just noticed I'd need something like https://www.lamonde.com/c0-04rtd.html to use pt100 probes, which is v. expensive. Maybe I won't be playing with PLCs ;)

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Re: ITC-308 troubles!

Post by guypettigrew » Wed Jul 28, 2021 4:14 pm

PeeBee wrote:
Wed Jul 28, 2021 2:18 pm
My understanding is the compressor, once started, should run for at least n minutes, and once stopped shouldn't run again for n minutes. The ITC-308 will do neither of those things. But that is by-the-way, because the real issue is the failure to maintain a steady temperature reading.
Not sure what you mean by this, PeeBee.

The compressor runs until the set temperature is reached. May take 2 minutes or 6 minutes. It then won't turn on again for how ever long the delay has been set for.

You've called both the run time and delay time 'n', but there's no reason they should be identical.

Guy

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Re: ITC-308 troubles!

Post by MashBag » Thu Jul 29, 2021 6:39 am

I am going to plug a bell (alarm) into mine - that will certainly tell me it there is an issue.

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Re: ITC-308 troubles!

Post by PeeBee » Thu Jul 29, 2021 9:45 am

guypettigrew wrote:
Wed Jul 28, 2021 4:14 pm

Not sure what you mean by this, PeeBee. …
It delays switching on the cooler when the ITC-308 is itself switched on. This delay is the most visible effect of "compressor delay". But the same compressor delay should prevent the cooler starting after it last stopped. I didn't believe this was happening, but thinking about it I never set up situations to test it, whereas you, opening the cupboard door shortly after the compressor stopped, were providing a situation to test it and say it works. That's good to know! But it is not really the issue I'm griping about.

That issue is the unstable readings from the ITC-308. I'm still messing with my shelf coolers and using a ITC-308 to monitor (not control) the cooler. Only yesterday I saw the ITC-308 jump in an instant from 0.5C to 1.9C. It returned to 0.5C within a second. These "spikes" can be fairly common, several times an hour, and will be variable differences in temperature difference and speed (the spikes are always instantaneous skips up, but take variable times to return to the correct reading). Most spikes happen in an instant, but I have seen the ITC-308 "counting-down" the return to the correct reading (over several seconds). An instantaneous "spike" will trigger the compressor to start and then stop again as the ITC-308 returns to normal (if the "compressor delay" has already expired?).

Now whether these on-off pulses are damaging …
guypettigrew wrote:
Wed Jul 28, 2021 1:57 pm
… Does it matter if the compressor flicks on and off? Is it just an urban myth, based on compressors from decades ago, that this activity will destroy them.

We need a compressor expert to advise.
Yes we do, don't we. Who's going to come forward who we can believe … . I've yet to hear of a fridge, freezer, etc. that has been trashed by this error.

Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... V1bWc/view

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Re: ITC-308 troubles!

Post by MashBag » Thu Jul 29, 2021 4:18 pm

Would an rc4 temp data logger test/prove/explain this issue for you?

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Re: ITC-308 troubles!

Post by PeeBee » Thu Jul 29, 2021 7:10 pm

A what? ... Ah,https://www.youtube.com/watch?v=KdHO3FBseKc, though that Elitech one may not pick up erroneous spikes 'cos it only measures every 10s and I reckon it should be every 1s (but an hour, 3600 points, should be more than enough, though some do seem to show the fault more often than others).

Inkbird won't be interested; they'll say you did it wrong, or will ask why are you baking 24 blackbirds in a pie, or something like that.

Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... V1bWc/view

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Re: ITC-308 troubles!

Post by PeeBee » Fri Jul 30, 2021 10:19 am

PeeBee wrote:
Thu Jul 29, 2021 7:10 pm
A what? ... Ah,https://www.youtube.com/watch?v=KdHO3FBseKc, though that Elitech one may not pick up erroneous spikes 'cos it only measures every 10s and I reckon it should be every 1s (but an hour, 3600 points, should be more than enough, though some do seem to show the fault more often than others).

Inkbird won't be interested; they'll say you did it wrong, or will ask why are you baking 24 blackbirds in a pie, or something like that.
Hang-on though. these data-loggers measure temperature themselves, not the temperature the Inkbird displays! Silly me! So, no, it wont help.

Although used in conjunction with something logging whether the compressor is active or not it should pick up the anomalies. Of course, Inkbird will be even less interested in such a "fabricated" log (can you be less interested than zero interest?).

Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... V1bWc/view

McMullan

Re: ITC-308 troubles!

Post by McMullan » Fri Jul 30, 2021 2:25 pm

I've had 2 ITC-308s for several years now. Also have a couple STC-1000s, which I believe the ITC-308 was based on mainly, an ITC-310 and even an ATC-800 that's been in continuous use for 8-9 years. After spending much time in my 'brewery' experimenting and executing various projects I can't say I've ever observed these so-called 'spikes' in any of my temp controllers. And I'm a very curious professional observationist experienced in the dark arts of science. My gut feeling is you're typing shite, again. In fact, I'm convinced there's a trend here.

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Re: ITC-308 troubles!

Post by PeeBee » Fri Jul 30, 2021 3:51 pm

McMullan wrote:
Fri Jul 30, 2021 2:25 pm
... My gut feeling is you're typing shite, again. In fact, I'm convinced there's a trend here.
The trend being ... You can't be ar$ed to read the supporting link. It's not just what I'm writing.

You are still a complete arse'ole aren't you "McMullan". Don't know why I bothered to make your posts visible again. I guess my real issue is I believe defective people can come right again. I'll learn eventually.

Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... V1bWc/view

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Re: ITC-308 troubles!

Post by vacant » Fri Jul 30, 2021 4:38 pm

I've seen a couple of the videos that show an instantaneous jump. It's either electrical interference - I'd try moving the equipment to another part of the house, or aliens - did you wake up the next morning after having weird dreams with a sore butt hole (i.e. sore for no good reason you can remember)?

HTH

McMullan

Re: ITC-308 troubles!

Post by McMullan » Fri Jul 30, 2021 6:40 pm

PeeBee wrote:
Fri Jul 30, 2021 3:51 pm
McMullan wrote:
Fri Jul 30, 2021 2:25 pm
... My gut feeling is you're typing shite, again. In fact, I'm convinced there's a trend here.
The trend being ... You can't be ar$ed to read the supporting link. It's not just what I'm writing.

You are still a complete arse'ole aren't you "McMullan". Don't know why I bothered to make your posts visible again. I guess my real issue is I believe defective people can come right again. I'll learn eventually.
You have troubles spelling, too, I see. 'Supporting evidence'? :lol: If I had a penny for every time a superstitious numpty posted utter shite on the internet I'd be a multi billionaire several times over. Obviously, one key area where we clearly part is what we accept as 'evidence'. I suspect I might be a bit more demanding than you on that front. Look up the phrase 'evidence' and, if you've got time, look up 'problem-solving' too. Then, hopefully, you won't be so easily misled to type shite online :wink: There's no charge, it's free advice. You're welcome :D Thank you for your output.

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