STC 1000 Temp controller - Wiring Issue??

[wideass]

Hey there everybody ,
Hope this finds you well and Viral free,
I'm trying to get an old Chest freezer going that had an STC 1000 Temp controller (unsuccessfully) installed.
I'd like to be able to use the freezer for food stores , in this time of need!
Be grateful for any help with the attached image
cheers

 

[Grok]

Can't see how the brown and white wires are connected to the compressor and this info is essential, and also need to know where/what the wires come from. Take off the cover on the compressor relay, and take a pic and post it. The power going to Terminal 1(T1) & T2 are isolated from the relays and only for powering the circuitry inside the stc1000. The relays need their own power in (and out)!
If you don't know what I'm talking about, you would be best to get a sparky to do it for you.
Is the original thermostat (if its still there) on full?

 

[Dingerb]

Hi Wideass,

The ST1000 is basically a switch.

The ST1000 takes a reading from the temp sender and then sends a signal to the switch to complete the circuit to allow the power to flow to allow the cooling or heating to occur.

So, cut the power wire and connect both cut ends in the the cooling or heating terminals as required.

In your case, when the temp drops lows enough the switch will close completing the circuit to turn on your fridge compressor.

Your earth and neutral don't need to be touched.

In my case UK wiring.
On the right is the brown live and blue neutral to suplly the ST1000
moving right to left.
2 black wires are the temp sender
then 2 brown wires (actually one cut) for heating
and finally
2 more brown wires (once again one wire cut) for cooling.

hope this helps.

Davie

 

[livo]

I'm not sure if the OP found his answer from this but I have a similar question and this is a fairly recent thread so here goes.

I've just made a temp control box out of a STC1000 and have it controlling a fridge. Fisher and Paykel fridge only (no freezer) which means I can stack 2 fermenters in it. It is working perfectly set at 22'C and yesterday I got to test it out on both heating and cooling. Really stable with settings of F1 @ 22'C, F2 @ 0.5'C, F3 and F4 default 3 minutes and no calibration. I've just got the probe in a 5 litre bucket of water to buffer against door opening etc.

My question is about using the fridge as a fridge for whatever reason, but mostly in the application of "Cold Crashing" once fermentation is complete. I've not done any cold crashing before and I'm not sure of the merits, if any, which is another question for somewhere else. Of course, I can just pull the plugs out of the control box and run the fridge direct to 240V, but I was thinking of including a switch in the control box circuit to break the Active power supply to terminals 5 and 7 of the STC1000 and divert directly to terminal 8. In doing this, the STC1000 would remain powered and still reading temperature from the probe, the heating element would become inoperative and the cooling controlled by the fridge thermostat, without needing to pull plugs. I can do it and think it will work as it would just be diverting the active with neutral and earth still connected. Has anybody done this or is there a problem with the STC1000 that I don't know about? I can't see anywhere that it has been done and I wonder why.

It should be possible with a standard 10 amp 240 V light switch to make / break the Active connections required. You can wire these to do two-way switching so they are mechanically suited to this application. With the temperature inside the fridge being below F1 the Heat circuit would switch to allow current but have no active feed. The Cool circuit would be off (open switch) but there would be live active at terminal 8. Would this cause damage to the unit? I can't see why it would.

I'd like to know your thoughts.

Cheers
Livo

PS: The other option is to change F1 setting to 2.5'C but I think I would prefer to let the fridge thermostat control it in this instance.

 

[sifty]

I've used a couple of these controllers with heaters in old fridges, and in both cases have removed the fridge thermostat from the circuit altogether. So the controller setpoint determines whether the fridge is heating/cooling.

Fermenting, and the fridge will heat/cool to maintain (say) 20 degs, then when cold crashing simply changing the setpoint to 3 degs will drive the fridge output to meet that...

Means when you want to keep your stouts at the perfect temp you can just set it to (say) 12 degs too...

 

[duncbrewer]

I used to use STC 1000 and disable the fridge thermostat. Then just use the stc 1000 to control the cold crash, set it for whatever temp you want but as cool as possible and do something to mitigate against suckback if you aren't pressure fermenting.
I just stick the temp probe on the side of the ferment vessel with a big piece of blu tack ( or putty if you have some of that) and then some high density foam ( from a sleeping mat over the top held on with a bungee.
You want the controller to react to your changing beer temp, if you buffer the temp sensor in a 5litre container it'll all get quite warm before that 5 litre changes temp. I use an ispindel as well and that gives a nice graph of the ferment temp change as well.
Do check that your temp probe is accurate and adjust if necessary ( on the stc).
Now using a brewpiless that is really accurate for temp control and it interfaces with the ispindel as well.

 

[CaptainMachSnot]

Hi Livo, from memory when I pulled my stc controller apart a few years ago, i think the unit uses surface mount relays, so there should be no problem back feeding the active into the terminals 8 or 6.

As has been said, it would only work provided the fridge thermostat wiring was still intact

 

[livo]

Yep. Fridge intact and that's what I was thinking would be the case.