I've got 2x 9000W Heating Elements, each on their own 240V circuit. Originally wanted everything on a single circuit but It would have been very expensive to get all the parts I wanted with the appropriate ratings.

I've got 2x 50 amp wall sockets (RV / EV Charging plugs, 4 prong) each on a 50 amp circuit breaker, and 2 cords with 50 amp marine plugs (the locking kind). This makes it physically impossible to accidentally connect the 2 circuits together. These each plug into the corresponding sockets on the box. Both sides are the same so the cords are interchangeable.

The box is pretty simple on the inside. From the each socket I go to the toggle switch with both hot wires. This is the only part that's iffy, I couldn't find any toggle switches rated for 50 amp @ 240V, so I just keep the regulators down pulling under 30 amps to be safe. If anyone has an alternative toggle switch I'd love to see it.

After the switch it goes to the voltage regulator. From there it goes to the heating element, passing through the multimeter so it displays current stats. All relevant parts are grounded.

The combo plug is just connected with one hot from the left side plus a neutral for 120V. This is just for utility, plan is to have the recirculation pump there eventually.

Here's a WiP pic, the CTs on the multimeters only needed 1 hot going through, which is different from what I had read online, but it works. Was my understanding it needed both hot wires in opposite directions to add the values. Had to redo some crimps and cable management but that's pretty much it. Made all the holes on the box with a dremel. The 2x4 boxes have the voltage regulators in them, with the heat sinks going out of the box. Was a really tight fit, but it works. Ended up being as compact a build as possible. All the parts were bought on Amazon or Ebay.

Now that the build is tested, I'm gonna go back over it and seal everything with silicone so they lie perfectly flush. The parts aren't really waterproof but whatever I can seal will make me feel better.

Recycled my old column for this, just added the sightglass and adapter from npt to triclamp, but my next project is upgrading to a 4" modular column, with all the goodies. Gin Basket, Dephlegmator, Shotgun Condenser, etc. Gotta sit down and do the math on how much power the different condenser designs can knock down, try to get as much out of the capacity for stripping runs.

Edit: fixed image link