Wiring up a 12V STC-1000

[Dr Horrible]

I have a STC-1000 operating happily away at home thanks to lots of wiring advice on this site, but I'm looking at a new setup with 12V DC power (battery).  I've bought a 12V STC-1000, but am a bit uncertain about how the wiring is different from the 220AC, any advice from those with greater electrical knowledge would be greatly appreciated!

[LordEoin]

If whatever your powering is going to be less than 10amp you could hard wire the live wire routed through ports [5+6]heat and [7+8]cool. This would be my choice.
If you're going to be running something stronger like a boiler element, then you'd need to run them out to higher rated relays.

List out what you're connecting to it and maybe a plan will form 

[Dr Horrible]

I thought something similar when I ordered it, but it turns out it's 12V in and 220VAC out. So I'll have a positive and negative cable to go in but a live, neutral and earth for both the  heating and cooling going out.  The diagram with the unit is the same pretty useless one that  comes with the standard 220AC in, 220AC out unit and looks like you just connect your cables directly to the unit but I don't believe it at all.  There was a really clear diagram that got posted  here for the 220AC unit, it might have been yourself that did it, LordEoin, and I'm looking for something similar for the 12V - I've been googling it but just get the 220V diagrams.

[LordEoin]

It's the exact same unit but you're running the probe, screen, board on 12v.
The built in relays are the same. they just act like light switches. The 12v part simply tells the switches when to turn on.
So to use those relays to control something 220v it would be easiest to hard wire it in.

I did make that diagram. I'll see if I can bastardize it up to show what I mean.

[Dr Horrible]

I'd appreciate it if you did, I have a bit of a blind spot when it comes to electronics.  Planning (to keep herself happy) to move out to a shed with no power for brewing, so will be doing everything from a 12v DC supply.

[LordEoin]

it really doesn't make any sense to me without knowing what you're using for heating and cooling.
If everything's 12v you should be cool to just wire it up as normal (although i'm not sure if you can run a 12vDC through a 220vAC relay)
but if your heating and cooling sources are 220v like a brewbelt and a fridge then i suppose this would be the easiest:
but if you've no power in the shed then this will be of no use to you

[Dr Horrible]

I was planning on getting 12V heatiing and cooling units but when I saw you could use a 220V output I thought I'd  use what I have.  Heating will be a 220V brewbelt, cooling will be a 220V pump - it circulates cold water through a stainless coil in the fermenter - going to hook up a 12V cooler to the battery for a source of cold water - I was using ice water bottles from the freezer, but  the sbed is too far from the house for that to be an option any more.

[Shanna]

I was planning on getting 12V heatiing and cooling units but when I saw you could use a 220V output I thought I'd  use what I have.  Heating will be a 220V brewbelt, cooling will be a 220V pump - it circulates cold water through a stainless coil in the fermenter - going to hook up a 12V cooler to the battery for a source of cold water - I was using ice water bottles from the freezer, but  the sbed is too far from the house for that to be an option any more.

Any idea of where to get the the 12v cooler and will you that all of the time or will that be on a seperate thermostat?

Shanna

[Will_D]

So do you have 220 v available in the shed?

Reading your posts I am a bit confused!

If you have then use it for heating and cooling and just use a 12 volt power supply to power the STC. As stated above the STC does not "output" anything, there are just 2 relays that switch whatever is connected on and off

If you don't have mains then where is your 12 volts comming from?

[Sorcerers Apprentice]

It seems that there is confusion over the volt free switching contacts on the stc, they are rated to carry 230 volts but there is no voltage output from them. They are just a switch. A 12volt cooler is based on peltier cells but will not give anything near the cooling capacity of a refrigerator plus the battery won't last very long if it is driving a 60watt heater.

[Dr Horrible]

The 12V supply will be from a battery, I've no other supply.  I suppose I was being a bit optimistic in assuming that there was an AC/DC converter in there, but the 12V in and 220V out on the schematics threw me off - I was planning on using a 12V heater and pump but when I saw the 220V output I thought I could get away with my existing equiipment.  Now I look at it again, it's a 12VAC supply which just makkes it more confusing!  However, it is possible to run an STC-1000 from a car battery, lots of guys are doing it.  Unfortunately they all seem to be chicken farmers using the STC to control the temperature of their incubators and I really don't want to go browsing through chicken forums to find out the wiring detaills!
Shanna, I was intending to have the 12V cooler running continuously so that I always have a supply of cold water.  LordEoin, thanks for the drawing, I'll give it a shot and see how it goes - I guess the worst that can happen is it won't work
Sorceror's apprentice - I don't think I'll need the cooling capacity of a fridge, this will be way more efficient.  The heating may be an issue, but this is a first pass to get a good idea on how many batteries I might need to keep it running - with good insulation and the heat from the fermentation I'm hoping to reduce energy usage.

[Sorcerers Apprentice]

You could happily run a 12volt solar pump from the battery switched through the stc, using a cooler box full of ice and a cooling jacket around your fermenter, if you add salt to the water in the cooler box then the temperature of the brine solution will drop to -6 but will cause corrosion to any metal fittings or pipes

[Dr Horrible]

Cheers - I guess if I go with 12V pump and heater then it's just a case of wiring positives with positives and negatives with negatives through the STC and have a common earth?
I'm currently using a similar water cooled setup in my house and haven't found that I've needed brine, water at 7-8deg is sufficient even for a lager - unless of course the ambient temperature suddenly shoots up 10deg, like what happened two days ago which has meant a lot of fun for me and a sudden decision to introduce a fairly long diacetyl rest! But that's another story.