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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.

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Are you using a temp mate? Cos if you are then they have a time delay thingy in them to stop it blowing the motor of the chest freezer from turning off and on! I thought similair when i first set mine up, but turned out i just had to leave it on for 5 mins before it would switch it on...

If its not that, then i have no idea...
I am using a universal temp controller a shimaden sr35
It does not look like it is a compressor delay thing (a Tempmate feature), more likely it is because you have not bypassed the freezer's thermostat. So that means that although your new controller detects that the freezer is warmer than you want it and it is 'turning on' the feeezer by supplying power to it, the freezer's own thermostat says that it is already cold enough by its standards and won't therefore engage the compressor. So you need to take the freezer thermostat out of the loop so you are directly contolling the compressor with your controller only - ie so when your controller turns on the power, the compressor comes on no matter what. (although the Tempmate delay feature is a good thing to have to extend the life of your compressor)

I did this in my fridge setup by having a good look at the wiring and identifying which wires went to the thermostat and which ones went to the comperssor, and simply removing the thermostat connections and making sure there was a direct connection from the live and neutral wires direct to the compressor. (don't disconnect any earthing wires!)

If you cannot figure it out it may pay to have a sparky or fridge guy do it for you, it should only be a 5 minute job.
I didnt think you needed to bypass the thermostat with a freezer cos when a freezer is cold enough to turn off its freezing, not just fridge temperatures... I just plug my fridge straight into the temp mate, no bypassing here...
Reviled how do you find your TempMate. I see you can set a temperature delay around your target to start heat/cool circuit. Just wondering if that gives you a more consistent fermenting temp. In my setup as soon as heating turns off cooling turns on which I think gives me a bigger temp range and a lot more on/off for my fridge. Ta
i dont use temp control for fermentation dale, just for my keg chesty :o)
really so no issues with temp rise and drops in your house? Every room in my house goes +/- 10C this time of year.
With a Tempmate you set a range, say +- 0.5 deg. When it gets to your target plus 0.5 deg the cooling comes on until it is down to target, then cooling turns off. Heating won't come on unless the temp drops to 0.5 deg below your target. So a lot less on/off, and a fairly stable temperature with max range about 1 deg, probably less. And the compressor delay feature is good for prolonging the life of your fridge!
Thanks Nick,

Thats does make a little sense, and I have the know how to make the adjustments... but I still cant get my head around the frezzer being warm (turned off for a month or so) so no matter what the source of power to the freezer, buy its own standard it is not cold enough and should swtich on...

I can understand that when the freezer is at operating temp there would be thermostat conflicts.
Hmm, that is still a mystery. Have you left the freezer/controller setup turned on for an extended period of time? (just wondering if it is simply a compressor delay built into the freezer itself that is doing this). If the temp controller is turning on/off other appliances light a light bulb correctly it must be supplying power to the freezer OK. How about putting a lamp into the circuit downstream of the controller as well to confirm power is going to the freezer. when you think it is. I suppose you have already done this.

If you have the temp controller set up and 'turning on' the freezer, and the freezer does not respond, then you immediately unplug the controller and plug the feezer directly into the power does the freezer come on straight away?

When powering the 1200W element, was this direct or via a relay? I note from your specs that the max amperage for the controller seemes to be 2.5A (unless I amreading it wrong?), the 1200W element would draw more than this. Not sure what the freezer would draw?
First paragraph is yes, I have already done this... and yes to paragraph two..

I think you nailed it in your third paragraph mate, I think the controller did control the element through a relay... and 2.5 amps is probably not enough to kick the compressor into life?, how would I overcome this?
Get a 240V solid state relay from Jaycar, they are about $10. I have just been using one, thier part number: SY4042 which will switch up to 20 Amps. You basically wire this like a switch, with your live 'in' connected to the 'com' post on the relay, your live out (to the freezer) to the 'on' post, and the output from your controller (it looks like your terminals 8 & 9) to the two other posts (on the relay they have a little picture of a coil running between them). I am not a sparky, so if you are at all unsure get one in! (Anyone else on the forum care to comment on this amateur explanation?)

If the freezer itself draws only 2.5A when running, there may be another way to get the compressor going, with a capacitor I think - on electric motors they sometimes have a 'capacitor start' to overcome the requirement for an initial high draw to get the motor running, but I have no Idea how to set one of these up.

Then again, a relay is going to protect your controller from drawing too much current and damaging itself......


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