Mini Digital Temperature Controller

[troublebrewing]

Nice diagram, very neat.

If you are short of space, you could eliminate connectors 4, 5 and 6 and amalgamate the neutrals at 7 into 2 (assuming there is sufficient room for the cable).

What program did you draw this with? Really neat.

[Samahon]

Thanks troublebrewing, I agree with your findings but I wanted to keep the diagram as simple as possible to avoid confusion with the non electricians among us.

I illustrate for a living, mostly product labels, posters, logos, unique corporate design, the list is endless.
Although I done this illustration in Adobe Illustrator, many pieces of software are usually used depending on the subject...

Thanks again... Now if I can just post an image correctly I'll be made up....

[jmc]

+1 Very neat diagram.

Easy for non-electricians to follow.

[JonA]

Sorry if this has been answered, but could somebody who's using one please confirm whether these STC-1000 controllers can handle the inductive surge from a freezer compressor, or do they need an additional relay wiring in. (just trying to avoid blowing mine up too quickly)

Thans, Jon

[TheFlatulentCow]

Sorry if this has been answered, but could somebody who's using one please confirm whether these STC-1000 controllers can handle the inductive surge from a freezer compressor, or do they need an additional relay wiring in. (just trying to avoid blowing mine up too quickly)

Thans, Jon

I've been using one of those to control a chest freezer for the last couple of weeks without issue so far.

Cheers.

[Samahon]

I use mine primarily to control temps for the fermenter. For my HLT I use an SSR (PSR-25) wired through a Pot (potentiometer) this allows me to control the power going to my element. When the water is boiling I can turn the power down to a few amps to keep it that way. Just allows me to have plenty of boiling water on hand for double brews/sterilisation, it also helps to keep the cost down which I really like...

@JonA... The inductive surge from a freezer compressor can vary from model to model, while 10A is a descent amount of wattage, the high inrush surge could max out the controller, shortening its life. To keep it safe I would wire in a 240 Vac - 30A relay to the cooling lines. Last time I looked it was about a fiver for the relay and the socket. I have wired relays into the circuit for friends who controlled HLT's whilst heating but never used one on the cooling side for a freezer. As TheFlatulentCow say's he has had no problems with it... I'd still stick an inexpensive relay inside the box, but thats just me...

[Andy]

Looking to use one of these controllers + a suitably rated external relay to switch the 3kW element in my HLT. I'd put the controller on a timer switch and have it come on in the early hours to heat the liqour.

In order to achieve this I need to know a couple of things about the controller which hopefully someone on here can help with.

1. When the unit receives power then does it start working without the need for the "power" button on the unit to be pressed ? (If my timer powers the unit up at 4am then I want it to start working without me having to press anything).
2. In a similar vein, if I set a "desired temp" and then switch the unit off then will it remember this desired temp when it's next powered on ? (I would want to set the HLT temp the night before a brew and then switch the unit off and have it all spring to life at 4am, remembering the temperature I'd set and just doing its thing without me pressing anything).

Ta!

[troublebrewing]

1. - yes, it will start up 'knowing' what temperature you are aiming at.
2. - yes, see above (same question really).

watts/volts=A

3k/240=12A (thereabouts).

[Samahon]

1. When the unit receives power then does it start working without the need for the "power" button on the unit to be pressed ? (If my timer powers the unit up at 4am then I want it to start working without me having to press anything).

Yes, it will do this... My STC comes on immediately without pressing the Power button. If I press and hold the PWR for 3secs then the STC will power off. Likewise, if I press and hold the PWR for 3secs when in the off state the STC will power on...

2. In a similar vein, if I set a "desired temp" and then switch the unit off then will it remember this desired temp when it's next powered on ? (I would want to set the HLT temp the night before a brew and then switch the unit off and have it all spring to life at 4am, remembering the temperature I'd set and just doing its thing without me pressing anything).

Yes Andy, it will store the setting you input...

Ta!

Hope it helps... What time controller do you have in mind? Will you use a common Power Socket type or integrate a module onto your controller box?

[Andy]

Thanks for that, excellent!

I was thinking of having an integrated timer and found some on ebay which were a DIN rail fitting. But I haven't researched the DIN format and so don't know how that would work with a case (housing the controller and relay). I have an electronic plug-in timer thing which will suffice but having a digital timer integrated would be nice.

[Samahon]

Saw this on Ebay Andy... It's only 16A but since you would have a =>20A relay installed anyway, I don't see a problem. Cheap as well and I'm all for that...

Hope it helps...

[Andy]

Ooo, nice one - thanks.

[troublebrewing]

Are we entirely sure that it is safe/good practice to wire an immersion element into a plug? I think not.

edit:
Just checked on that and it seems ok to do so.

[Andy]

Are we entirely sure that it is safe/good practice to wire an immersion element into a plug? I think not.

Of course not. But I'm not doing that The immersion element is wired into an existing 16A socket, the control box I'm building will be powered from a conventional 13A socket and will be used to switch the separate immersion element circuit using a relay in the control box. The relay isn't the one in the digital temp controller but is one driven by the controller and the relay will be rated to switch the immersion element circuit.

[troublebrewing]

I see, I assumed you were, sorry. Anyway, as I say in my edit, I don't think there would be a particular problem with doing that, you just wouldn't do it with a domestic immersion tank, that's all.