Kenmore 94689 + brewpi fermentor build

[cegan09]

Nothing earth shattering, but figured I'd share. Bought a Kenmore 94689 to be my new fermentor. My old one was doing double duty as a kegorator and I need them to be separate at this point. I'm using a standard brewpi build for a controller.

I put together an acrylic case to house the controller. Everything is contained in the case, Raspberry Pi 3, arduino Uno, two channel relay board, wall plug USB charger, LCD screen. There are two connectors, one handles power in and out of the box, and a headphone jack for the thermocouples.

As for wiring:
Potato cam picture of the stock wiring diagram.

I interrupted the white wire from the compressor and sent it to the controller where it splits to connect to one pin on the charger and the input to each relay. Then the outlet of the relay goes to the interupted compressor wire (and eventually to the heater). I also grabbed the black wire to run to the other prong of the charger. So that's 4 wires in/out for power. White wires were changed to red simply so they'd be more visible.

A look at the wiring hooked up to the controller.

Now I just need to solve the LCD scrambling issue.....


I'll update once I've added the heater and wired in the thermocouples properly (waiting for a few more to show up)

 

[day_trippr]

Looks great, aside from the whole "switched neutral" thing.
Be sure to plug the BrewPi box into a GFCI circuit just to be safe...

Cheers!

 

[cegan09]

Looks great, aside from the whole "switched neutral" thing.
Be sure to plug the BrewPi box into a GFCI circuit just to be safe...

Cheers!

I should have added i'm a mechanical engineer and electricity is not my strong suit. In my mind AC power means it doesn't mean which side you switch. If there's serious reason to not switch on the neutral side I will revise the wiring.

 

[day_trippr]

If you trace your household neutral (white) wire back to the main electrical panel, you will find it is bonded to earth ground (and if your home has metal plumbing and gas lines, you'll find they're also bonded to earth ground - or should be by Code).

Thus you can grab a neutral wire and a ground wire with wet hands with complete safety.
Do not try that with a hot wire.

Switching neutral violates Electrical Codes because it leaves the hot side "hot" and therefore available to light someone up by accidental contact, though they may have believed the circuit was "off"...

Cheers!

 

[cegan09]

Good to know, thank you. I would have guessed that they'd use the opposite colors for that since black is often used as a "ground" color. Looks like I'll go swap out how I have things wired. Not hard, just need to interrupt the other wire to the compressor and restore the white wires.