I’ve been collecting parts for the past several months for an all electric single level EHERMS build, using Kal’s great E-Brewery system as a reference and model, as well as all of the other great systems that have been shared on HBT, and particularly those drawn up by PJ. I'm using a re-purposed stainless steel control panel (16"x16"x7") that I reclaimed from a salvage yard for $14. I've included some pics of the box. When I got it it had a single hole in the top, and a bunch of extra holes in the bottom. I ended up cutting out the top and installing a heat sink, and cutting out the unwanted holes in the bottom, and making a new plate out of sheet aluminum. I had the front holes cut out from a source on Craigs list (the steel is about 62 mils thick, and was hard for me to work with at home). I ended up polishing the whole box and heat sink, and the last 2 pictures show it with most of the controls in place - I still have to clean off the extra silicone around the PIDS and timer.
The control panel will be powered from a 60Amp GFI Spa Panel that’s fed from a 50A 2 pole 240V breaker. There will be two 5500W (240V) heating elements – one in the BK and one in the HLT (all converted keggles). I’ve got 3 Auber PIDS (BK, HLT, and the 3rd will just be to monitor the temp of the MLT) and a Sestos timer. I’ve come up with a preliminary wiring diagram, but would appreciate it if you guys would check it out, and tell me what I’m missing and/or doing wrong, and answering a few questions that I have.
1. I want to have a main power switch that controls both live legs, and since this is just an on off, I think it’s alright to use the lit selector switch to activate the 2 pole 240V controller – but should the coil for the contactor be 120 V, or 240V for this, and do I have it wired right in the diagram?
2. For costs, I really didn’t want to put in circuit breakers into the panel. What size fuses should be used for the heating elements, and where should they be placed – just after the controller?
3. I’m right now only planning on using one of the heating elements at a time, although with a 50 amp service I’m probably OK with all the loads. I’m using an on-off-on three way selector switch that will determine which of the elements can come on, and the switch will also control a green light for either of the elements, similar to Kal’s. Do I have this circuit wired right – with the switch controlling the power to the coil of the controller?
4. I also have to figure out how to wire the alarm(s). Do all the alarm signals from each of the PIDS run in parallel to the light and horn?