A Thing To Connect AC Wires Better

Line AC power is a lot more dangerous than low-voltage DC power. As such, it requires different methods of connecting wires together temporarily. For example, you can use the same wire nuts used for permanent connections, though it’s not particularly fast or repeatable. You could just twist the wires together, but just because you can do something, it doesn’t mean you should. A modest step up in safety is wrapping the twisted wires in electrical tape, but that’s not particularly convenient or safe. You can use things like crocodile clips, but I didn’t have any on hand and many are too thin to handle much current anyways. Finally, terminal blocks and bus bars are moderately safe (if you don’t touch them, the connections will stay as they are), convenient (it’s just a screw connection), and can be purchased at most hardware stores and used to connect power to your devices/projects.

Since I value time much, much, much more than money, I decided to try to make some busbars out of copper pipe. First, I flattened two 75mm pieces of 3/8″ type L annealed copper tubing. Then, I drilled four holes to accommodate some #10-32 stainless steel machine screws (what I had lying around), put the screws in the holes, and soldered them in with plumbing solder so they wouldn’t move or turn. To make a connection, a wire was sandwiched between the copper bar and a fender washer, then tightened with a nut (see pictures and diagrams).

I made a wooden base to mount the bars on consisting of two pieces of wood on top of each other. On the top piece, I drilled some pockets to fit the screw heads protruding from the bottom of the bars so they could sit flat on the wood. Then, I hammered two nails from the bottom of the wood so they stuck out the top and bent them to hold each bus bar in place. The other piece of wood had pockets drilled for the nail heads and served to cover the nail heads (which are electrically connected to the copper bars, and thus live) on the bottom of the first piece.

I also 3D-printed a socket wrench to make turning the nuts easier, though I’ll probably just replace the hex nuts with wing nuts in the future.

And now, diagrams and pictures to put in context the nonsense I just spewed out.