Get a PID temperature controller for your Cave

[bmckee561]

I have worked with Automatic Temperature Control for many many years and never considered using my skill and knowledge to control my Hobby items at home with such controls, until recently that is!

I started off making a Beer Fermentation Chamber to Lager some of my Home Brews and when it is not in use, I use it for my Cheese Cave.  Since we are now into the cold weather season, I can dedicate this equipment for cheese aging.  So I put the following items together and use it to control the temperature inside the cave.

The cost for all 3 items is close to $70.00 plus shipping, but it allows me to control a small refrigerator at higher than normal temperatures.  I can now set my cave to any desired setting from 35F all the way up to ambient (room temperature).

The site I used is http://www.auberins.com.  You might want to swing by and check out the items shown if you are interested in getting better temperature control of your cave.

Salute!   

[mikeradio]

I have been using PID in the control of my smoker to control the temperature.
They make life a lot easier 

[bmckee561]

Mike:  I have a PID controller which employs an analog output to control my electric element for my smoker/HLT/Double Boiler.  The PID varies the electrical output from 0 - 120VAC to maintain very tight temperature control  It is quite portable and I can quickly inter-change the thermocouples for each set-up I am using.

I agree they make things so much easier to control.  I get way better smoked product now then when I just used the controller on the smoker heating element.

Salute!   

[acstokes]

bmckee561,

I see that these are digital, but otherwise, are these PID controllers better than the Johnson Control analog controller that's so popular? If better, why?

Thanks,
Fred

[bmckee561]

Better in that they allow for adjustments to setpoint much easier and more accurately.  You can make changes to differential from setpoint a lot better than one of the analog controllers.  They don't improve on the actual on/off control just the temperature control adjustments and monitoring.

The display on the PID controller shows you actual temperature inside the cave too.  I do not believe you have that capability with the Johnson analog controller.

As far as cost comparison goes, they (PID) may be a bit pricier, but will in the long run, do an overall better job of control.

Salute!   

[OlJarhead]

THanks -- For $33 I think that might be the ticket.  My fridge cost me $25 but I'm willing to spend a little on a PID.

[Groves]

I'd love to hear more about these PIDs and how you determine which components go with each other. Digital readouts do delight the eyes.

[steampwr8]

What did you use on the refrigerator control side, a solid state relay (SSR) or contactor?

Also what type of thermalcouple did you use? From the picture it looks like the K type. I believe the RTD would give the system the ability to auto tune (auto calibrate).

[bmckee561]

The PID shown above can be wired directly.  No SSR is needed.  You simply use the wires going to the thermostat for the refridgerator and run them to the PID controller.  I use a 10K sensor as shown above.

Hope you give it a try.

Salute!   

[steampwr8]

If I understand correctly and interpret the PID manual, you wired the control wires of the internal thermostat to the J1, terminals 4 and 5. Most of the time these 'wires' switch the compressor motor directly.

This is an internal relay with a 3 amp 240vac rating. How big is your cave fridge?

[bmckee561]

I have a medium/small unit, but the rating on the PID controller should be able to handle normal sized refridgerator.  I don't have the manual available right now, so I can't be absolute about that.  You could add a small relay that would handle any current draw over the limit of the internal contact in the PID.


Salute!   

[steampwr8]

I am mulling the design using the PID you have. I read the manual for it on the Auber Instruments sight and the internal contacts are rated at 3A max 240VAC.

That would be just adequate for our small 4.3 cu ft caves, but a large refrigerator pulls >15A starting and the older ones run at 4A to as much as 8A. In that case I would spend the additional $15.00 for the solid state relay and run the cave through the SSR 25A contacts and control it using terminals 9 and 10. It may be safer to do it this way with small caves as you isolate the 120v of the cave from the 120v of the PID.

You have a great design for an affordable price. I would take it one step further an insure the safety by using a higher rated set of contacts of the SSR.

[Pondering Turtle]

I am new to cheese making and am looking at what to get after getting a kit from my girlfriend for christmas.  As she also got me a book that discusses many kinds of cooking and I took notice of Sous Vide cooking.  Could you use one of these controllers to control either the cooling of a cheesecave or the heating of a crockpot for sous vide?

It does seem that the required equipment for sous vide is all applicable to cheese making then.

[THE_COW_IS_OK]

Currently, I use my aurbin PID with my rice cooker for sous vide cooking.  The PID supply variable output voltage (0->120V) with very frequent power switching. Should I be concerned driving a fridge compressor with that? I only experienced it with simple resistance element.

[mikeradio]

Yes you have to be carefull with which type of PID you use for a fridge.  You can not turn a compressor on and off like a heater, it will damage the compressor.  You have to make sure the PID has a latched output, which will stay on until the temp is reached, then turn off and stay off until the upper temp is reached.  It has to have some differential in the temp ssttings.

Mike