My system is completely electric. It uses a single dedicated 50A circuit fed into a box in my garage which contains a GFI breaker that then feeds the brew stand. In the control box, the circuit is then divided into two circuits, one for the HLT and one for the brew kettle. Each circuit is controlled via a 30A, 250V, DPST switch, so that when I am done with one particular vessel, I can shut it off. The HLT is controlled with a single Love temperature controller using an AC triggered SSR. I plug in the temperature I want the water to reach, and the controller switches the HLT on/off as needed. The brew kettle is powered by a Payne controller, similar to this, which is essentially a solid state power triac, which then feeds into another AC triggered SSR, and then into the brew kettle. (This extra SSR is a little redundant, but it allowed me to make a simple on/off toggle switch that switches off the power to the AC trigger of the SSR to shut off the brew kettle without reaching to the side of the control box and flipping the heavy duty switch). The HLT contains a regular 4500W high density element, and the brew kettle contains a 4500W extra low density element, similar to this one. The kettles are two converted kegs, the elements attach to the kegs with one-inch couplers that were welded into the kegs. For the electrical connections on the outside of the kegs, I JB welded electrical boxes with small circles cut into them over the couplers, screwed a box cover to the box with a small square cut out, and wired in an appropriately rated three-prong male receptacle (from mouser.com, on this page if I remember correctly). This ensures that if the kettle were somehow unplugged during the brew session, no wires or terminals would be exposed for a person to accidentally touch. (And conversely, on the control box, the plugs are the opposite, with female receptacles on the control box and male plugs on the cords) On the bottom of the kegs, I screwed in some copper grounding screw terminals to ensure a good ground connection at all times.
I'll try to take some pictures tomorrow if I can remember, but my stand isn't nearly as good looking as baltobrewer's... mine is very much still in a 'beta' state... my pump isn't yet wired into my control box, and my control box itself is just made out of wood for this first version, I plan on eventually replacing it with a proper NEMA enclosure. I was also going to do something similar to baltobrewer with regards to using a plate chiller as a heat exchanger, but I am a little disappointed by his reports that he is unable to step mash with it... so I may reconsider going that route after all... that being said, I've brewed somewhere near 30-35 batches on this since December and I am very happy with how it is working out thus far.
P.S. - It should go without saying that if you aren't familiar with electricity, and any of the above doesn't make sense to you, you probably should not attempt this project. Electricity at this level of current is very dangerous.
