DIY Temp Controller for Freezer?

**CollinsBrew** · 05-01-2007, 05:32 AM

I was wondering if anyone had a less expensive way or could point me in the right direction of making a temperature controller for a freezer that I am going to use for lagering?

I can get a Johnsons for $50 at www.bevergefactory.com but am trying to not spend a whole lot more money on my setup than I already have this month. Any DIY's on this? Thanks!!

**Yuri_Rage** · 05-01-2007, 05:38 AM

Hmm...not sure if I can come up with one that's too much cheaper. Check eBay for Ranco ETC-111000 controllers - sometimes you can find them for around $30.

**Jaybird** · 05-01-2007, 06:02 AM

that rancho ETC works good as Yuri said SOMETIMES 30 bones but few and far. 50 bucks is a really good deal consider it my gift to you..... just send it to yourself COD
JJ

tron · 05-01-2007, 06:09 AM

you might be able to rig up a temp controller with a dial control for AC. I believe they go down to 50 degrees and you could wire that in to the thermostat that is in the freezer. i think this would be pretty easy if the thermostat for the freezer is simple like two wires, i have not done this only thought about it for future use. let us know if you decide to go this route.

**CollinsBrew** · 05-01-2007, 01:33 PM

I found this last night while looking through some other posts. He says something at the bottom of the page about not being able to hook up 120 Vac because it will blow the capacitor.

Would the relay he is talking about work for the power plug to the freezer and if it did would it be cost prohibitive? Also, is there any way to tell the temperature differential to keep the unit from clicking on and off constantly?

**Yuri_Rage** · 05-01-2007, 05:10 PM

EDITED (different relay part number)

You'll need a power supply (wall wart) capable of switching the relay. You could use a 12V relay and cheap power supply. I know, that doesn't help make it cheap, but if you want a relay that could be controlled by the batteries in your thermostat, it'd cost another $25.
Here's something to consider with that project - you'll need (assuming you have a soldering iron and solder):
RiteTemp Thermostat - $24
Relay - $7
Power supply - $6
Wire - ~$5 (I like to use short extension cords - they look professional and don't cost much)

Now you're up to $42, which is roughly the cost of a purpose-built temperature controller in the first place.

On the bright side, it looks like a fun project...

**Yuri_Rage** · 05-01-2007, 05:34 PM

Quote:

Originally Posted by CollinsBrew

Also, is there any way to tell the temperature differential to keep the unit from clicking on and off constantly?

This installation guide has a few good notes:

http://www.ritetemp-thermostats.com/images/8029B_installation_guide.pdf

It doesn't list the temperature differential, but it does indicate that it has a "4-minute minimum off time in COOL."

**CollinsBrew** · 05-01-2007, 08:47 PM

If I were to purchase a Ranco ETC that's not prewired how would I attach the power to the freezer to the controller?

**D2T** · 05-01-2007, 09:19 PM

Quote:

Originally Posted by CollinsBrew

If I were to purchase a Ranco ETC that's not prewired how would I attach the power to the freezer to the controller?

Look at the bottom of this page for a PDF that outlines wiring for the Ranco temp controller: http://www.honeyrunapiaries.com/store/goldline-sp30-replacement-ranco-p-88.html

It's not very difficult. Just take a short extension cord, cut it and wire as shown. Drop me a PM and I can supply some pictures of mine if that helps.

Beerrific · 05-01-2007, 09:35 PM

Quote:

Originally Posted by Yuri_Rage

EDITED (different relay part number)

You'll need a power supply (wall wart) capable of switching the relay. You could use a 12V relay and cheap power supply. I know, that doesn't help make it cheap, but if you want a relay that could be controlled by the batteries in your thermostat, it'd cost another $25.
Here's something to consider with that project - you'll need (assuming you have a soldering iron and solder):
RiteTemp Thermostat - $24
Relay - $7
Power supply - $6
Wire - ~$5 (I like to use short extension cords - they look professional and don't cost much)

Now you're up to $42, which is roughly the cost of a purpose-built temperature controller in the first place.

On the bright side, it looks like a fun project...

I was going to do something like this for a fridge I have. I got a Ranco instead, the price difference would have been nothing because I was going to use the thermostat from my house and buy a new programmable one for my AC.

I went with the Ranco because of the probe, I can put it wherever, don't have to worry about the thermostat in the fridge or removing anything from it.