STC-1000 temp. controller wiring confusion

Hi folks, I've been searching the various STC-1000 threads but can't seem to find an answer that's applicable to my application.

I have a Woods V10NAA upright freezer that I am converting to a fridge. I want to replace the existing thermo with the STC directly but am having some troubles figuring out the wiring. It seems as though most conversion schematics include a white wire which I don't have.

Inside the freezer behind the thermostat I removed there are (3) wires: a thick RED wire, a Black wire and a much lighter gauge green.

The freezer's power cord has (3) wires: one strand goes up into the freezer, color unknown, the lighter guage green wire which also goes into the freezer and then the last strand which is connected to a white wire going into the compressor.

The only other wire going up into the freezer is a thick red wire coming off the compressor.

I've attached a pic from the inside behind the old thermo, underneath by the compressor and a snap of the wiring diagram from the back of the unit.The wiring diagram shows a white wire near the top of the freezer connected to the light... but this freezer doesn't have a light)

Can anyone help?

-- and of course a snap of the STC-1000

From the schematic it appears that the white wire is neutral coming from your power cord. You will have to splice into it before it goes into compressor and attach to #2 on the STC-1000. Your black wire which is the hot coming in from your power cord will need to go to #1 (power in) and #7 (cooling power input). Your red wire will need to go to #8 which is cooling output. This should control your refrigerator using the STC-1000 probe. Hope this helps.

So looking at the second pic above:

The black will goto #1,
The Red will goto #8,
The Green ?
I will need to splice into the white wire from the compressor and run a new lead up to the STC.

That sound right?
What gauge would the white be?

Appreciate the help!

Is it possible the RED is the main feed, it's a much heavier gauge ?

CanadaColdBeer said:

So looking at the second pic above:

The black will goto #1,
The Red will goto #8,
The Green ?
I will need to splice into the white wire from the compressor and run a new lead up to the STC.

That sound right?
What gauge would the white be?

Appreciate the help!

Click to expand...

The black will go to #1 and and also to #7 to provide power for cooling. You can take the black wire and two short pieces of black wire to make a connection with a wire nut. Then strip back the ends and tighten down each wire on #1 and #7. I would use the same size wire of the power cord which will probably be #14(15 amp) or #12 (20 amp) The green wire is your ground and doesn't have to be connected to the STC-1000 but needs to remain connected to the refrigerator. You probably already know,but make your your refrigerator is unplugged before doing any of this. Electricity bites so you need to be careful and if your not comfortable with doing any of this ,I would definitely get someone with electrical experience to help.

CanadaColdBeer said:

Is it possible the RED is the main feed, it's a much heavier gauge ?

Click to expand...

If you have access to an multimeter or an Non Contact Voltage Tester you could verify for sure which is the main feed but according to the drawing it is the black wire.

unplug - check! (been bitten before once or twice..)

So two questions then:

If the black is the main and the red goes to power the compressor, shouldn't they be the same gauge?

When you say to splice into the white line before the compressor, do you mean to simply 'tap' into it or to cut it and ??

CanadaColdBeer said:

unplug - check! (been bitten before once or twice..)

So two questions then:

If the black is the main and the red goes to power the compressor, shouldn't they be the same gauge?

When you say to splice into the white line before the compressor, do you mean to simply 'tap' into it or to cut it and ??

Click to expand...

I would think black and red should be the same gauge of wire. Don't know why its installed that way but that's where the multimeter or non contact voltage tester would come in handy. You could plug in the power cord and carefully check which wire had power going to it.
Splicing the white wire consists of cutting the existing white wire , stripping both ends , adding another white wire to run to the STC-1000 and connect them together with a wire nut.

Just a thought but maybe the red wire to the compressor is sized bigger because the compressor runs hot. Heat will effect wire sizing.

So in a nutshell, here is how it will look - the white wire will be spliced before the compressor using a wire nut and fished up through to the STC to #2.

CanadaColdBeer said:

So in a nutshell, here is how it will look - the white wire will be spliced before the compressor using a wire nut and fished up through to the STC to #2.

Click to expand...

That looks correct

Where is the starting circuit for the compressor, is it inside the compressor housing?
If you don't know, most compressors are capacitor start, along with the standard "run" wire. The capacitor charges, and fires a jolt into the compressor so it will start against head pressure, and the "run" wire keeps the compressor on. If I read your diagram wrong, I apologize, please discard suggestion.

Well... that worked.

Now just for the finishing touches (mounting).

Thanks dford!

Is there a reason for tapping into the exsisting thermostat and not just wiring to the mains plug as im doing this myself and im at the stage for the stc-1000

I didn't modify the wiring on my freezer. I wired up my STC-1000, plugged in the freezer plug to the "cold" side set the thermostat on the freezer to the coldest setting, and called it good.

Yeah thats how im going to do it just wonderd wat the diffrence between that an wiring it to the origonal fridge thermostat

I replaced the thermostat in my freezer with the STC-1000. Makes it a refrigerator - freezer or anything in between with the push of a button. It was pretty easy too.

Did u take out the old stat ? Wounderd if the fridge still works without it or do u leave it in as i can gain more room by taking it out