Wire gauge sizes for SSR and RJ12

What is the recommended gauge size to connect BrewPi to the SSR via the Digital Outputs? Tried 14 stranded, but it just barely fits and needs some work to get it and stay in. Also what cable type is recommended for the 6 conductor RJ12 OneWire? Thanks again.

The amperage and voltage is likely pretty low… something like 3-5vdc @ 5-10 mA. I used a 20 or 22 AWG cable with two wires. The red ring terminals should fit well. As for the RJ12, the OneWire sensors are actually only using three of the wires in an RJ11 4p4c. (That’s what they come with) If you’re using the sensors from the brewpi store then just refer to the configuration of one of the plugs before you toss it. I used a stranded shielded three wire telecom cable to hook up the three pole circular connectors I used. Be aware that the sensors are addressed so you only need to run one cable to do both the fridge and beer sensors. Just wire them together. I only had to extend it out about a foot or so out of the fridge and then used the cable from the sensor I cut short that has the RJ11 connector on it. You could use a 4 or 6 wire phone cable for the whole length and just use three of the wires and terminate it if you have an RJ12 6p6c or RJ11 4p4c connector and the tool to do it. The soldering job is likely going to be a bit fiddly though if you don’t. The wires are pretty small. Just refer to the fridge hacking guide on this.

For all of my inputs/outputs from the Ardunio, I just used breadboad jumper cables. As Blankly stated, the amps/volts for the communication is low. Of course, for the other side of the SSR i used the same awg as the receptical i was using, in this case 14awg:


Thanks for the feedback. I have extra 18-2 security wire from a previous project, would using the 18 gauge wire pose any problem or risk damaging the BrewPi controller?

Can I just ask how are one-wire sensor wired to RJ11 connector? I plan to install RJ11 female socket inside the fridge, so the sensor can be disconnected when removing the fermentor out from the fridge. On the outside I need an extension cable. Are 4-wire RJ11 ADSL modem cables ok as they are? Or I need to crimp the plugs and re-wire it (different wiring than 3 wire sensor)?

For an RJ11 connector (4 pin):

1 = not connected (12V)
2 = 5V
3 = GND
4 = OneWire data

The full pinout for an RJ12 connector (6 pins):

1 = RS485-A
2 = 12V
3 = 5V
4 = GND
5 = OneWire data
6 = RS485-B

This is the pinout on the Spark side and on an expansion board side. So you want both plugs to look identical when you hold them next to each other. If pin 1 is yellow on one side, pin one should be yellow on the other side.

Thank you for clarification. Can you advise which cable I should buy to make an one-wire extensions. I have crimpers and will crimp connectors by myself.

4 or 6 wire flat cable. (4 wire for RJ11, 6 wire for RJ12). The extra 2 wires are not used yet (RS485) but are reserved for future extensions that will use the protocol. Right now, we only have OneWire extensions.

Something like this:

Unshielded is preferred, because the connectors are unshielded. The only thing the shielding strands will do is create a possibility for damage by touching the data/power wires.

So I can leave the two extra wires connected? Meaning I don’t need to re-crimp the cable if I bought the one you mentioned? Thanks again for great products & support.

Actually, i don’t know if that cable is straight or crossed. As I said before, both sides should be identical.

If the cable is straight, there is no harm to leave 2 extra wires connected (for future extensions)? If not, I will re-crimp it.

No the extra wires are no problem, but the pinout should be correct.