Running a freezer without internal thermostat

[KyleWolf]

This may be a stupid question. But I haven't really found the answer anywhere else. I am going to build a keezer from a chest freezer I acquired. The freezer doesn't work and I believe it is the thermostat. I know the thermostat is vital and required to control the temp of the freezer and turn the compressor on or off, but if I am using an external thermostat (johnson, Ranco, etc.), do you think it is possible to remove the internal thermostat all together? If I remove the thermostat from the entire rig and plug in the freezer, will it run?

Obviously purchasing another internal thermostat is an option, just trying to save money.

Thank you for your time. Again, sorry if it's a stupid question

 

[microbusbrewery]

It should work. The thermostat is basically just a switch. As long as you're using a temp controller, that becomes the new switch and will turn it off when needed. I'm currently working on my keezer and I was checking out the thermostat. On mine there are only two wires; one hot coming from the power cord, then the switched leg going to the compressor. If yours is the same, you'd connect the two then plug the freezer into your controller.

 

[KyleWolf]

I was hoping that would be the case. I will post a pic of the wiring when I get home this afternoon.

 

[brewskerdoo]

Before investing in a temp controller, if it were my freezer, I'd confirm that the thermostat is the problem. If the wiring isn't obvious, there's usually a wiring diagram glued to the back of the access panel or in a pouch in the vicinity that might help. You'll want to bypass the t-stat relay and apply power o the compressor and see if it starts. Also, the compressor start capacitor is a common point of failure to consider.

 

[KyleWolf]

I considered that it may be a problem with a component of the compressor. But the freezer is only 2 years old, so I was hesitant to suggest it. I will probably use a multimeter and continuity test to see if its the thermostat before I start ripping everything apart. I do have the wiring diagram that came with the freezer.

Thanks for the idea Brewskerdoo!

 

[brewskerdoo]

lol, yea, the multimeter / continuity check method is probably the less spark-inducing, breaker popping way to go.

 

[LovesIPA]

When I built my keezer and ferm chamber, I completely bypassed all the factory temperature controls and temp probe. The STC-1000 replaces everything but the compressor.

 

[KyleWolf]

I will have to read more on the STC-1000.

 

[KyleWolf]

So, when I plug in the freezer, I can hear the compressor kick on for a bit (30sec to 2min) and kick off, then it would randomly kick on for a few seconds if I fiddled with the thermostat. This leads me to believe it is indeed the thermostat that is the problem. However, after I detached the thermostat and plugged it in, nothing happened. I believe that the compressor requires the relay from the thermostat to kick on (see diagram) in order to work. Because of that I believe it may simply what I would have to do with the STC-1000 in order to directly integrate it into the freezer.

Below is a pic of the freezer and the numbered arrows correspond to the following.
1) Power to the thermostat [black wire] (from wall plug)
2) Power to the compressor [white wire] (from wall plug)
3) Relay from thermostat to compressor [yellow wire]
4) Ground wires [green/yellow wires]
5) Thermostat
6) Compressor
7) Connection for Compressor power and thermostat relay.


If the compressor has its own dedicated power wire, but requires the relay from the thermostat to turn on...am I able to simplify the wiring of the STC-1000 to this?

(1 and 3 correspond to the wires in the first pic)

I can do electrical stuff, but it isn't my specialty, so I can get a little off at times. Let me know what you think.

Thanks
Kyle

 

[beaksnbeer]

Wires 7and wire 2 is the supply for the compressor.
On your controller 1 (hot) and 2 (neutral) is your power in.
Wire 7 (yellow) will go to(8) the cool relay
1+7 on the controller will both be hooked the the hot wire on the wall plug.
2 on on the control will get 2(white wire off comp.) + the neutral off the wall plug

 

[LovesIPA]

Check out this post.

 

[KyleWolf]

Thanks everyone! I think I have it now!



Looking forward to getting it up and running!

 

[LovesIPA]

Yep, that's how mine are wired.