Maxi 110 Cooler Compressor switching on

The forum for discussing all kinds of brewing paraphernalia.
Post Reply
sladeywadey
Hollow Legs
Posts: 377
Joined: Thu Dec 03, 2009 5:56 pm

Maxi 110 Cooler Compressor switching on

Post by sladeywadey » Mon Jun 11, 2018 8:52 pm

Hi, I have a Maxi 110 cooler that I'm using with my GF conical and have noticed that the compressor is switching on at least twice within 10 minutes. This is the case even if the cooler isn't connected to my conical or anything.

I had a look inside the water bath and I'm definitely getting a decent ice bath.

Is this typical for these coolers?

Fil
Telling imaginary friend stories
Posts: 5232
Joined: Sun Oct 16, 2011 1:49 pm
Location: Cowley, Oxford

Re: Maxi 110 Cooler Compressor switching on

Post by Fil » Mon Jun 11, 2018 9:48 pm

no, although i run mine for 30-40 mins for an evenings pour, you can expect the chiller to run for a few hours to build up an ice wall and then shut down only restarting when the cold store(ice wall) gets diminished through use, at which point the compressor should run for 20+ minutes to make up the lost cold.

its probably a dodgy thermostatic controller within the maxi, thankfully its a fairly simple machine and quite modular so replacing the built in controller with an stc1000 sized device is fairly straight forward the difficulty being cutting the steel case to fit the new controller and the sometimes gotcha is letting the probe tangle with an agitator prop or clog the inlet for the recirc pump, a cable tie should sort that out..
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

sladeywadey
Hollow Legs
Posts: 377
Joined: Thu Dec 03, 2009 5:56 pm

Re: Maxi 110 Cooler Compressor switching on

Post by sladeywadey » Mon Jun 11, 2018 10:15 pm

OK thanks Fil - I have an stc1000 spare somewhere so looks like i'll be getting the multimeter out to see where I can hook it up. Are there any pics around showing one fitted at all?

sladeywadey
Hollow Legs
Posts: 377
Joined: Thu Dec 03, 2009 5:56 pm

Re: Maxi 110 Cooler Compressor switching on

Post by sladeywadey » Tue Jun 12, 2018 6:24 pm

OK I have now fitted the STC1000 and it is controlling the compressor/fan. I set the stc1000 to minus 0.5 and after a while, the STC1000 nicely turns off the compressor/fan.

However I now see what is happening - even though the therm probe is in the ice bath, the 0 degrees water that is being circulated around the ice bath by the agitator soon heats up the ice bath and within 5 mins of switching off, the temp rises from minus 0.5C to between 0.0C and 0.1C. Fortunately I have the 10 minutes safety feature set on the stc1000.

Does this indicate that the ice bath is not 'thick' enough?

Does anyone know what the standard thermostat turns the cooler off at temp wise? I might try setting minus 1 on the STC and see what that does.

Fil
Telling imaginary friend stories
Posts: 5232
Joined: Sun Oct 16, 2011 1:49 pm
Location: Cowley, Oxford

Re: Maxi 110 Cooler Compressor switching on

Post by Fil » Tue Jun 12, 2018 7:54 pm

my own limited experiments with a maxi 310 used for serving using a basic dial thermometer inline in a short return line on the recirc lines revealed that the waterbath temp drops to -4C with an ice wall formed and the compressor cuts off after the initial setup and turn on.
(Based on that i run mine for serving till it drops to 0c (circa 30-45 minutes) as that generally retains sufficient cold to chill my evenings pours)

another chiller i opened up the icebath revealed that an ice wall circa 2 -2 1/2 inches (5-6cm) thick had built up around the coolant tubes.. i assume thats the norm??

I would suggest setting up and turning on with a target temp beyond the capacity to reach ?-20C? and letting it run for 2-3hours or more? and monitor at what temperature the drop stops and levels out.. guesssing that it will be something between -5 and -2 ?? i would set that as target and trigger the compressor to come on @ 1-2C above, you know the compressor can do the chilling and imho as long as the coolant remains relatively cold compared to what its chilling, the compressor is better off running for 1-2 hour long runs than 10 or more 10 minute runs per day??

To actually build and maintain an ice wall you may need to hold the bottomed out temp for a period? however that probably isnt necessary as the icewall is there to provide a cold store for 'rush hour' pint after pint serving, When employed as a cold source for a FV your need is to contain and transfer enough cold to maintain your target temp and or chill down as needed for which an ice wall may not be required. If however its revealed through use/testing it is a timer delay could be incorporated into the project..
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

sladeywadey
Hollow Legs
Posts: 377
Joined: Thu Dec 03, 2009 5:56 pm

Re: Maxi 110 Cooler Compressor switching on

Post by sladeywadey » Tue Jun 12, 2018 8:19 pm

righto thanks Fil - I'll set it to minus 5C and see how we get on. Like you said I'd rather not have the compressor cycle constantly. It could be I have not set an adequate temp to start with when fitting the STC1000.

Now I know how to set up the wiring properly, when I've sussed the temperature side, I might replace the STC1000 with one of my esp8266 chips plus 5v -> 240v relay so I can wifi enable it and log things via mqtt etc. We'll see.

User avatar
Kev888
So far gone I'm on the way back again!
Posts: 7636
Joined: Fri Mar 19, 2010 6:22 pm
Location: Derbyshire, UK

Re: Maxi 110 Cooler Compressor switching on

Post by Kev888 » Wed Jun 13, 2018 11:38 am

It partly depends on the thermal coupling with the conical, and insulation of the pipes etc. If the maxi has to work hard to keep up with cooling demands of the FV then it stays on much longer, sometimes constantly. But if the FV doesn't need much cooling 'or' if the heat transfer between wort and coolant is poor, then the maxi will cut in and out more.

But I agree with Fil, that does sound more frequent than I would like, if it happens all the time. Now you have gone electronic, I too would change the temperature and/or time delay to make it more intermittent.

FWIW I run my maxi bath at about 16c when just maintaining fermentation temperature of 19c, I only drop it (to -5c) when chilling - after the fermentation. You don't get the buffer of the ice bank, but heat gain through the insulation is much less with the bath closer to ambient temperatures. Though you do need a good thermal transfer between coolant and wort, to work with a smaller temperature differential. I also recirculate coolant only when the FV calls for cooling, so there is little heat gain through hoses whilst just sitting there idling.
Kev

Fil
Telling imaginary friend stories
Posts: 5232
Joined: Sun Oct 16, 2011 1:49 pm
Location: Cowley, Oxford

Re: Maxi 110 Cooler Compressor switching on

Post by Fil » Wed Jun 13, 2018 11:48 am

check out tasmota for fully featured esp firmware out of the 'bin' ;) a compressor delay can be configured using the recent feature addition of 'Rules' and while mqtt and some sort of governing system is expected its got enough stand alone features to run in isolation too.
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

sladeywadey
Hollow Legs
Posts: 377
Joined: Thu Dec 03, 2009 5:56 pm

Re: Maxi 110 Cooler Compressor switching on

Post by sladeywadey » Wed Jun 13, 2018 1:22 pm

Hi Kev - currently with the STC1000 set to -2, the compressor is being switched on every half hour or so with the trigger set point being 0C. This at least is much better than using the standard thermostat. It takes 10 mins to drop from -2 to -0.1C then seems to stick there for 20 mins or so then the compressor is switched on. I might try putting the probe in a pipe/thermowell to try and reduce the drop time further when I've finished this current batch. All observations being made without my conical being connected up. I don't want to drop further from -2c as the ice bank is really thick as it is.

I like the ice bath approach as I can also crash cool with it too (well, down to 6C but that's fine for me). However if I wifi enable the setup then maybe I can do as you are doing and maintain a higher temp for the fermentation duration then remotely turn it down for cold crashing.

I control the heating and cooling of my GF conical with brewpi and I had to change the Brewpi software so that I get a minimum of a 5 second burst of cooling water at least every 10 minutes, otherwise the overshoot is too much by the time the FV probe has picked up on the cold water. This burst value is calculated real time based on differences between current and target. Over the last few weeks of testing this is working really well and I'm able to keep to target temp typically within 0.1-0.2C which is good. All hoses are wrapped and are not excessively long.

Fil I already use Tasmota for my home automation via sonoff devices so this might be a good fit, although I have an unused Smartpid device which might fit the bill nicely here. I also have a particle photon as well as several esp32's but the wifi is unreliable on these so I might experiment to see which is better.

Post Reply