Warwick316
Well-Known Member
I got this thermostat for free and I have no idea how to install it. Is it hard to wire to a fridge or freezer? Any help would be appreciated.
Old Johnson Controller Wiring HELP!
- Thread starter Warwick316
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pavs
Well-Known Member
Is there no cords coming out of it now? Usually theres a cord to plug in the wall and a female end e
to plug the fridge into.
to plug the fridge into.
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Warwick316
Well-Known Member
No theres no cord. That's probably why it was free.
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Warwick316
Well-Known Member
Here's a picture of it.
Looks like you have acquired an older Johnson A19 line voltage thermostat, here is the tech literature for those devices http://cgproducts.johnsoncontrols.com/MET_PDF/125035.PDF.
What is needed for cooling control is to use the bottom screw and top screw terminals on the switch for power switching. You need to bring the "Black" wire from the incoming power cord to the bottom screw terminal, and the "Black" wire in the outgoing power cord to the top terminal. Wire nut the white wires together, put lugs on the green wires and place the lugs under the "Green" colored ground screw in the thermostat housing if is still there, else use a #6 bolt and nut to attach ground lugs to thermostat back plate.
What is needed for cooling control is to use the bottom screw and top screw terminals on the switch for power switching. You need to bring the "Black" wire from the incoming power cord to the bottom screw terminal, and the "Black" wire in the outgoing power cord to the top terminal. Wire nut the white wires together, put lugs on the green wires and place the lugs under the "Green" colored ground screw in the thermostat housing if is still there, else use a #6 bolt and nut to attach ground lugs to thermostat back plate.
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Warwick316
Well-Known Member
So let me see if I understand. The male end of the extension cord that plugs into the wall, gets wired to the bottom and the female that the fridge plugs into gets wired to the top? Is that right?
Sounds kinda like you don't need to mess with it, but if you want to give a crack at it here is how I would wire it....
Male plug (outlet to controller) take black wire/hot wire/small prong wire and connect it to the RED of the controller(bottom lug). Now if you want it to cool you will connect your female plug (controller to the controlled) and wire your black wire/hot wire/small prong wire to the N.O contacts, which I think is on the top and would be yellow. Tie in your neutrals and grounds, also try to ground the controller in a safe matter.
If you are still unsure I could draw a picture I guess....
Male plug (outlet to controller) take black wire/hot wire/small prong wire and connect it to the RED of the controller(bottom lug). Now if you want it to cool you will connect your female plug (controller to the controlled) and wire your black wire/hot wire/small prong wire to the N.O contacts, which I think is on the top and would be yellow. Tie in your neutrals and grounds, also try to ground the controller in a safe matter.
If you are still unsure I could draw a picture I guess....
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Warwick316
Well-Known Member
I understand Thanks Max, im going to wire it up today.
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Warwick316
Well-Known Member
Well I wired it and it works great. Does anybody know how the differential on the side works?
The differential lever sets the temperature spread between switch trip on or off temperatures. The larger the differential number the more degrees of temperature change to get the switch to change state.
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Warwick316
Well-Known Member
Oh, ok Thanks Kladue. I just set it to the min so It the temp doesn't fluctuate too much.
I would advise setting it to a low number if it cycles the compressor often, better to widen the temperature spread to reduce the number of on/off events.
