Beginner building his system: questions about Powerswitch Tails, Onewire sensors, Tubular Heater

Hi there! I’m new to the forum and trying to build a brewpi system using method 1 from the fridge hacking guide (leave the fridge in its original state, just use two powerswitch tails).

I hope that my questions and reflexions can be useful for other beginners too…

I already have:

  • 70W / 220-240vac fridge
  • Raspberry Pi Kit Raspberry Pi 3 model B
  • BrewPi Spark v2 Brewing Temperature Controller
  • 3 Waterproof OneWire Temperature Sensor (RJ11, DS18B20) (two for the beer in carboys or plastic buckets, one for the fridge ambiant temperature)

Now I’d like to add a tubular heater, two Powerswitch tails (one for the heater, one for the fridge) and two thermowells for the sensors.

Therefore, I have a few questions:

  • Which powerswitch tails do I need? As I live in Switzerland where 220 Volts is the standard, I already figured out that I need two of those 240 vac kits but cannot tell the real difference between them. PowerSSR, zerocross or powerswitch?
  • How do you connect the powerswitch tails to the brewpi spark? Simple wiring?
  • I could connect all my 3 RJ11 temperature sensors directly to the brewpi spark. But that would mean that I would have to root all three sensors inside the fridge and I’d rather avoid that if possible. Is there any piece of technology (like a multisocket for RJ11) that would allow me to root a single wire from the spark to the inside of the fridge, where I would then connect all three sensors?
  • I haven’t found any website that sells tubular heaters in continental Europe. I’m probably doing my research with the wrong keywords in French and German. Does someone have any website/shop/alternative to recommend?
  • I plan to ferment in carboys and will therefore order some rubber bungs with two holes in it (one for the airlock, one for the thermowell). But I also want to ferment in regular plastic buckets. To be able to do that, I have the feeling that I’ll have to drill a second hole in the lid of my plastic fermentor and stuff the hole with a rubber lid grommet. Does anyone know where I could order that (don’t wanna order from the States and pay 40 bucks for a 49 cents item) or has an alternative suggestion?
  • Any thermowells to recommend from a website in Europe? I’ve read different topics where the ones from brewers hardware were recommended but the shipping costs are probably high… What is your experience?

Sorry for the long story and looking forward to get your opinions… Cheers!

I am using a system based on an earlier design, not a BrewPi Spark, but I have solved some similar problems.

For the RJ11 problem, first I used a couple of two-to-one RJ11 adapters, like this:

I had one cable from the controller, which split into two. One of these connected to a temperature sensor. The other connected to another adapter, to split it into two. I connected two temperature sensors to those. You can do this many times.

Now I have one of these, which gives me three connections for sensors, and two spares for testing or experiments:

You can also find a three-to-one splitter but be careful as they usually have one male RJ11 and three female RJ11s.

For a thermowell I am using a piece of silicone tubing. It is about 30cm long, and maybe 4mm internal diameter (whatever you can get). I am using a pre-made DS18B20 sensor with a metre of cable and a stainless steel cap. I removed the heat shrink sleeve from the joint between the cap and the cable. The silicone tubing seals around the cap and covers the joint. I left about 20mm of the cap exposed. At the other end the outside of the tubing seals against the inside of the hole drilled in the brewing vessel lid.

I decided silicone was safe to immerse in my beer, and it’s easy to sanitize the stainless steel and silicone by boiling.

I don’t know if anyone else has tried this, but it works well for me.

For my heater I am using heating tape which is intended to wrap around water pipes to stop them freezing in the winter. It is rated at 240Vac at about 30W.

Good luck with your build, and if you can’t find something specific to solve a problem- be creative.