Use the ITC 308 BUT as a thermostat switch?

[ihavenonickname]

Hi - I want to use the ITC308 in my fermentation fridge. In the passed I’ve use these by plugging the power cable of the fridge into the controller and it powers the whole unit on and off, but no I want to use it just as a thermostat switch (not powered) I don’t understand the wiring of the controllers enough to make this change, but surely it is possible right?
This is the thermostat I want to bypass and use an inkbird in its place hope this makes sense.

In the pics I have taken the two pink wires off the thermostat and put a plug on them thinking I could just plug it into my inkbird itc 1000 as is but that doesn’t work.

edit: if I’m better off using an ITC 1000 for this job that’s fine, actually that what I already have and probably should have just asked about that.

 

[day_trippr]

Those red and white wires aren't all connected together, are they?

You should be able to remove the connections to a typical bulb and capillary mechanical thermostat and route them through the "cool" relay path on any respectable controller like an ITC-1000 or one of the more modern Inkbird controllers. All you should have on those red wires is a "hot" from the line cord and a "switched hot" to the compressor start circuit.

Of course, you do still need to locate the Inkbird's temperature sensor inside the controlled compartment space...

Cheers!

 

[Bobby_M]

The ITC1000 works fine and it's probably easier because the relay contacts are right there to connect to. However, it still needs either a hot and neutral or hot/hot to power the electronics. You can just wirenut the two thermostat leads together on the fridge and plug the fridge in to the cooling outlet.

 

[day_trippr]

Well, the OP specifically stated the desire to not switch the unit via its line cord.
I could understand that if there are features that would be unavailable unless the temperature sensor was calling for "cold".
Like interior lighting.
It's all about choices

Cheers!

 

[ihavenonickname]

Right so what Bobby is saying I already know how to do and I have my ITC1000 wire up to work that way (plug in the power cord of a fridge and a heating mat).
What I want to do is (?)change the wiring in my ITC1000 so that i stead of plugging in the whole fridge I just plug in the two wires that were going to the thermostat. Can I “Take away” the power part of the cooling side?

 

[day_trippr]

Yes, as I wrote earlier, you should be able to make your idea work. You do need to supply the 120vac (or 240vac, depending on ITC-1000 model) to power its internal logic, but once that's accomplished you can re-route the thermostat wiring to use the Inkbird's Cool relay to mimic the original mechanical bulb-and-capillary thermostat function - ie, close the Cool relay when the ITC-1000's temperature sensor triggers a cooling cycle...

Cheers!

 

[ihavenonickname]

Ok great yes thats exactly it….
How?!?
Cut the red or blue to the cool outlet?

 

[Bobby_M]

Ok, for starters, disconnect that lamp cord and plug because those red wires are not the hot/neutral "input" to the system. Think of the stock thermostat as touching the two reds together when cooling is needed and then pulling them apart when not needed.
If you use the ITC1000, the two red wires connect like this to lugs 7 and 8. You would still have to supply hot/neutral to 1 and 2 to power the unit.

 

[ihavenonickname]

Oh bummer I don’t have a multimeter, I didn’t think those wire would be hot as they just go to the old dial thermostat.

here’s how it started in the fridge:

here’s how I have my ITC wired, it was 10 years ago I set this up but I’m pretty sure I just wired it how the instructions say (like the image in my other post above)

 

[Bobby_M]

Well, most likely one of those red wires is hot because it's tapped into the hot on the main fridge power supply while the other is going to the compressor. Like I said, the stock thermostat either touches the wires together (or not). That's exactly what terminals 7 and 8 on the ITC will do. Now, that's completely different from the way you were using the ITC in the lower picture. If you put the two red wires on 7 and 8 (with any other wires removed from them), it will work just like you're asking for.

 

[ihavenonickname]

Oh sweet, yeah that’s really simple!