Setting up a chest freezer...

[Adrian Tayler]

Does anyone have any idea why my chest freezer works fine when it is plugged in directly to the mains but will not work when the power is intercepted by a temp controller?

a. the temp controller, controls heating and cooling (has been used to power 1200W elements)

b. other applicances work when connected..

Someone mentioned that you have to bypass the thermoatstat on the freezer and controll the compressor with the TC ??

Help please?

cheers, Adrian.

[Adrian Tayler]

Now your talking.. I have one of these Solid State relays at home , it is 240v..

[Nick T]

Looks like it will do the trick! You may want to attach it to a low amp device first time around to check that it is set up and working OK before running serious electrons through it, unless you are feeling confident......

[Dale]

Am I reading that photo wrong Nick, isn't the relay controlled from a DC supply with an AC output? Isn't a freezer all AC?

[Adrian Tayler]

it is switched by a 12v DC supply so yeah it will need to have a 12v source which I have... Good call Nick, I will run a lamp on it for a while first... thanks for your help mate.

[Adrian Tayler]

attached is my understanding of the setup.. what do you guys think?

[Nick T]

Hi Dale - well spotted, I didn't notice that - however, looking at the specs for Adrian's controller it look as though the controller output to the SSR is DC, so he may be OK as is without a transformer.

This is a timely reminder for me to check my (just wired up) PID controller specs to make sure the SSR output matches the required input for my relay before testing it!!!

[Dale]

Nick will have to answer that one. In my case I wanted to use the control for heating and cooling and be able to move round. So I made the setup as in below link. I plug mine into the wall then plug heating and or cooling in the 3 pin plugs and then put my probe into fementor.

So in this setup I don't bypass themostat in fridge but turn it right down.

[Adrian Tayler]

the controller does not have a DC output.. so I will need a 12v source to switch the relay on full time? this is starting to get confusing now !/

[Nick T]

Adrian, I think it might not work. See attached for my take on it. (I may be wrong though, I am not qualified in this area!)

[Adrian Tayler]

I think you are on to it Nick.. next prob is that the TC does not have a DC output ??

[Nick T]

Um, are you sure about that? See attached marked up copy of your specs, I have highlighted the two places where it says (I think!) you do have DC output, the second one is in fact the same as the wiring diagram I posted just before.

[Adrian Tayler]

Yeah, I just looked that up.. Your on to it.. Thanks mate.. I will report back as to how I get on... If I dont.... hmmm I will probably be crackling... :-)