wine cooler control

[Ponchik]

I have a client that has a large wine cooler. The thermostat control is not working anymore and the cooler keeps running. The company who made it is out of business. So I am thinking I can install a thermometer inside to control a relay to turn the power off/on when it gets to a certain temperature.
Where can I find a thermometer/relay combo that is prewired for this set up and it is plug & play. Otherwise I would have to get the separate parts and set it up myself.

Thanks for your replies.

 

[MNSparky]

Whats the voltage and amps? Single or 3 phase? I did something similar once with a RIB relay, a 120-24v transformer and a regular heat-cool thermostat. It worked really well and the customer was able to fine tune the temp in the wine cooler with the thermostat.

 

[Ponchik]

Whats the voltage and amps? Single or 3 phase? I did something similar once with a RIB relay, a 120-24v transformer and a regular heat-cool thermostat. It worked really well and the customer was able to fine tune the temp in the wine cooler with the thermostat.

I am assuming it is 120V. I still have not seen the cooler but we have been talking over the phone.

Heat&cool thermostat? That should work assuming it is a big enough cooler.

 

[iwire]

I am assuming it is 120V. I still have not seen the cooler but we have been talking over the phone.

Heat&cool thermostat? That should work assuming it is a big enough cooler.

Stay away from room / area thermostats. The range won't be correct and the differential ( the number of degrees between on and off) will be too great.

I would go with a Johnson Controls A419. It's a very common digital control used in commercial refrigeration. It's easy to set up and has adjustable differential. About $60 to $100.

It can handle 16 amps at 120 volts, far more than a wine cooler.

http://cgproducts.johnsoncontrols.com/met_pdf/125188.pdf

 

[iwire]

It also has a remote probe so you can install the control inside or outside the cooler. Only the probe needs to be in the cooler.

 

[kwired]

I have a client that has a large wine cooler. The thermostat control is not working anymore and the cooler keeps running. The company who made it is out of business. So I am thinking I can install a thermometer inside to control a relay to turn the power off/on when it gets to a certain temperature.
Where can I find a thermometer/relay combo that is prewired for this set up and it is plug & play. Otherwise I would have to get the separate parts and set it up myself.

Thanks for your replies.

Make sure it isn't a refrigeration problem.

If it "keeps running" because the thermostat failed to shut it off it should get colder then desired inside. If it never gets too cold but never too warm, it might just barely be keeping up even though it never gets cold enough to shut down.

Also keep in mind higher efficiency appliances like this often will have long run cycles but at lower output rates then older less efficient units.

 

[Ponchik]

Make sure it isn't a refrigeration problem.

If it "keeps running" because the thermostat failed to shut it off it should get colder then desired inside. If it never gets too cold but never too warm, it might just barely be keeping up even though it never gets cold enough to shut down.

Also keep in mind higher efficiency appliances like this often will have long run cycles but at lower output rates then older less efficient units.

That is a great point!!

I don't think it is a high efficient unit because the client said it was installed about 20 years ago.

 

[FionaZuppa]

any inexpensive PID controller that has direct input for thermocouple (or integrated) is also an alternative.
i believe that Johnson Controls item is inexpensive, just seems bulky (well, its relative to the size of the win cooler, under counter vs basement size, etc)

and btw, its 2017, stay away from mechanical relays, use proper SSR :thumbsup:

https://www.hvacpw.com/johnson-cont...86AC6A571103&gclid=COzj4r3Uv9ECFecV0woduJ0N6A

and other http://www.davis.com/Product/Thermocouple_Temperature_Controller_Type_K_and_J_110V_F/YX-93520-01

 

[qcroanoke]

That is a great point!!

I don't think it is a high efficient unit because the client said it was installed about 20 years ago.

If it is 20 years old I personally would be looking for something new.
Unless it is built in or there is some other reason it would be a pain to remove and move another one in.
But if he wants to keep it I'd look hard at what Iwire has suggested, he works in coolers and refrigeration in supermarkets a lot
and should know of what he speaks.

 

[Jraef]

It's not something to be taken lightly. You need to have the proper "hysteresis" in the on and off range of the temperature controller, otherwise you can short-cycle the compressor and burn it up.

I'd root around and find the dead component, then take it to a Refrigeration / HVAC supply house and get a direct replacement part. They are good at that.

Here's a good supply chain I use a lot in the West, but your profile doesn't say where you are.
http://www.rsd.net/locations.php

 

[iwire]

It's not something to be taken lightly. You need to have the proper "hysteresis" in the on and off range of the temperature controller, otherwise you can short-cycle the compressor and burn it up.

Can you explain what you mean, since 1999 90% of my time is supermarkets and the refrigeration that comes with them and have never heard the word hysteresis used when talking about compressors.

 

[mpoulton]

Can you explain what you mean, since 1999 90% of my time is supermarkets and the refrigeration that comes with them and have never heard the word hysteresis used when talking about compressors.

It's the "deadband" - the temperature difference between the turn-on and turn-off setpoints. If they are too close together, the compressor will run too often for too short of a time.

 

[mpoulton]

any inexpensive PID controller that has direct input for thermocouple (or integrated) is also an alternative.
i believe that Johnson Controls item is inexpensive, just seems bulky (well, its relative to the size of the win cooler, under counter vs basement size, etc)

and btw, its 2017, stay away from mechanical relays, use proper SSR :thumbsup:

https://www.hvacpw.com/johnson-cont...86AC6A571103&gclid=COzj4r3Uv9ECFecV0woduJ0N6A

and other http://www.davis.com/Product/Thermocouple_Temperature_Controller_Type_K_and_J_110V_F/YX-93520-01

Have to be very careful with PID controllers on refrigeration equipment. Most PID controllers are not intended to operate compressors, so the PWM cycle time is much too short even on its longest setting. The cheap Chinese PID controllers usually have about a 10-second to 3-minute adjustable range for the PWM cycle, which is just not long enough to make a compressor happy. It will try to cycle the compressor for only a few seconds at a time. If you choose a controller with a much longer PWM cycle you can do it, but it's still not really very good for the compressor because any PID system will cycle it way more often than a normal thermostat. The Johnson Controls A419 programmable thermostat someone recommended is designed for this application. I'd use that instead.

 

[iwire]

It's the "deadband" - the temperature difference between the turn-on and turn-off setpoints. If they are too close together, the compressor will run too often for too short of a time.

In my area that would be called the differential and the control I recommend it has adjustable differential and short cycle protection if you want to program it in

 

[FionaZuppa]

Have to be very careful with PID controllers on refrigeration equipment. Most PID controllers are not intended to operate compressors, so the PWM cycle time is much too short even on its longest setting. The cheap Chinese PID controllers usually have about a 10-second to 3-minute adjustable range for the PWM cycle, which is just not long enough to make a compressor happy. It will try to cycle the compressor for only a few seconds at a time. If you choose a controller with a much longer PWM cycle you can do it, but it's still not really very good for the compressor because any PID system will cycle it way more often than a normal thermostat. The Johnson Controls A419 programmable thermostat someone recommended is designed for this application. I'd use that instead.

i happily disagree with you (http://blog.opticontrols.com/archives/344)
most PID controllers will also have a std threshold (deadband) mode, does exactly the same thing as the A419. you can get whats needed on Amzon for ~$16

PID is bit "smarter" than deadband mode :thumbsup:

 

[Johnnybob]

It's not something to be taken lightly. You need to have the proper "hysteresis" in the on and off range of the temperature controller, otherwise you can short-cycle the compressor and burn it up.

I'd root around and find the dead component, then take it to a Refrigeration / HVAC supply house and get a direct replacement part. They are good at that.

Here's a good supply chain I use a lot in the West, but your profile doesn't say where you are.
http://www.rsd.net/locations.php

But it does! Somewherrrre over the rainbowww!:angel:


:rotflmao:

 

[mpoulton]

i happily disagree with you (http://blog.opticontrols.com/archives/344)
most PID controllers will also have a std threshold (deadband) mode, does exactly the same thing as the A419. you can get whats needed on Amzon for ~$16

PID is bit "smarter" than deadband mode :thumbsup:

Well if you disable the PID function and use it as a regular thermostat then it's not really a PID controller anymore I'd say. The A419 has a built-in relay suitable for controlling a small compressor, and it's a fully enclosed rugged unit that's known to be highly reliable. For $78 it's a pretty good deal. The cheap units have their place, but a customer's wine cooler might not be it.

 

[FionaZuppa]

Well if you disable the PID function and use it as a regular thermostat then it's not really a PID controller anymore I'd say. The A419 has a built-in relay suitable for controlling a small compressor, and it's a fully enclosed rugged unit that's known to be highly reliable. For $78 it's a pretty good deal. The cheap units have their place, but a customer's wine cooler might not be it.

right, if you run PID in deadband mode then its not doing PID. your point is what? my point was, with most PID's you can run a few PID modes, or just a deadband mode.

$17 deadband, 10A rated relays, heating & cooling (https://www.amazon.com/gp/product/B00OXPE8U6/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1)
smaller than the A419 too.

not saying the Johnson item is bad, just saying there are alternatives

and btw, i had a 10A rated relay controlling my HVAC motor, inrush amps is near 30A, running amps is 13A. the relay held for a few years (it was an engineering err, wrong relay for the job).
if the wine cooler compressor is huge then i would use a avalanche rated Omron SSR as the power relay.

options ---> http://www.kegerators.com/temperature-controllers.php

 

[Jraef]

I suppose deadband was a better term than hysteresis... old habit, sorry. :ashamed:

 

[kwired]

right, if you run PID in deadband mode then its not doing PID. your point is what? my point was, with most PID's you can run a few PID modes, or just a deadband mode.

$17 deadband, 10A rated relays, heating & cooling (https://www.amazon.com/gp/product/B00OXPE8U6/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1)
smaller than the A419 too.

not saying the Johnson item is bad, just saying there are alternatives

and btw, i had a 10A rated relay controlling my HVAC motor, inrush amps is near 30A, running amps is 13A. the relay held for a few years (it was an engineering err, wrong relay for the job).
if the wine cooler compressor is huge then i would use a avalanche rated Omron SSR as the power relay.

options ---> http://www.kegerators.com/temperature-controllers.php

If using a "process controller" with PID abilities, even if you have a relatively "cheap" controller, it probably isn't able to switch the motor/compressor current, meaning you will need additional relay/contactor and likely an enclosure to house it in. The unit Iwire suggested is a stand alone item and will switch smaller motor loads (I think).

If this is a typical residential grade wine cooler and is 20 years old, sounds like it would cost the owner less to just purchase a new one.

I still think if the only symptom is it "runs all the time" it either needs refrigerant or maybe just needs the condenser cleaned.