Below I will attempt to show, with pictures, how to wire an stc 1000 temperature controller for cooling ie, to turn your freezer into a keg fridge, or a fridge into a fermentation fridge.
When used for fermentation some people like to have the heating side in operation to limit the parameters of temperature fluctuation. I am not worried about this so long as the temperature does not go above the required temperature for fermentation. Using the stc 1000 in this way you can set the parameters to whatever you want, for example, if you want to ferment at 18°C you can set the controller to start the fridge compressor when the temperature rises to 18.1°C (64.4 F). The compressor will then run until the temperature drops to 17.6 C (63.7F).
This is the equipment I used, a jiffy box, a 5 metre extension lead, An stc 1000 temperature controller with sensor and lead, 2 x cable glands and a 6 way cable terminal post.
These are the tools I used to get the job done. Not shown are an electric drill and a jigsaw for making the holes and openings in the jiffy box.
First job is to mark, drill and cut the jiffy box. Then dry fit the components to ensure a good fit.
Then find the centre of the extension cord and mark three sections to be cut, approximately 100mm per length.
Cut the lengths from the cord.
All the wires can have their ends stripped ready for connecting. Needed are the 2 cut ends of the extension cord, 3 x brown wire (100mm each), 2 x blue wire (100mm each), 1 x earth wire (100mm).
Pull all the cables, including the sensor cabling, through the holes and glands made for them. Pull through more than you need to, to ensure ease of wiring.
All of the wire connections have now be made. Hopefully you can see the male and female plug ends to see the placement of the connections.
A closer look at the wiring connections.
Here is the wiring schematic for an STC 1000, with thanks to lambert. This diagram shows the wiring for both heating and cooling, I only wired mine for cooling.
Almost finished, Everything is now in the jiffy box and it just needs the base screwed on.
Finished product, tested and working.
I hope you found this helpful.