I recently completed an installation of a NMEA 15-50 plug in my basement to plug an eMotorwerks Juicebox Pro 40. It was too big of a deal, and with a little assistance from a knowledgeable Craigslist contractor, I think it went off without a hitch. Here’s my experience.
I decided to call in a pro, but for that pro, I went with a Craigslist general contractor that “has experience with electricity,” rather than a full blown electrician. The initial quote I got from an electrician to install this plug was $1800. Seemed like extortion to me. The contractor I got came out once to look over the project and advise me on where the conduit should go, and which materials I should go with. He came out a second time to make the final connections to the electrical panel. All in all, he cost me $300. It was about $200 in materials, and I got a $200 Dewalt impact driver (I love this thing, and will get Dewalt Max XR tier stuff from now on). Still way ahead that initial bid, and I got a fancy drill out of it: For The Win.
My Juicebox is installed on a concrete wall in my basement. I drive the Leaf into the basement. The plug and conduit goes up to the wooden beam, then over to the panel, down a concrete wall again, and into the panel. Total run is about 25′.
While the Nissan only draws about 24 amps (6.6kw 240v) the charger can max out at 40 amps and therefore needs a higher rated plug and wires. I used 3x 6awg thhn wires, and one 8awg green ground wire. I consulted an EMT fill chart, and found I’d be using 3/4 conduit. The contractor recommended renting a Roto hammer from Homedepot and Tap-con screws to go into the concrete. I used my shiny impact drill to drive those screws into the holes. Be sure you look at the box of screws to get the screw size and hole size matched with the bit on the Roto-hammer (one more hardware store trip).
Also, the length of the screws is important. At one point I’m screwing nearly flat galvinized conduit clips into concrete, 1 1/4 were sufficient; 2 1/2 would strip out before biting and getting screwed in far enough. Another place, I was drilling through a 5/8″ piece of plywood. Get a few different lengths of Tap-con screws to save a trip (another hardware store trip).
While measuring and cutting conduit, measure twice cut once of course. Use a rat tail file to clean up the inside of your cut conduit. I didn’t bother with a bender. I just purchased 10′ lengths, a few 90°s, and some little conduit box offsets to get from the deep 2 gang box to a conduit that’s also flat against the wall. You can leave all the couplers a little loose as you’re holding the operation up to where you think it needs to go.
I didn’t use the 25′ wire snake I bought. Once I’d bundled the thhn wires together, I was able to shove them 3/4 of the way through the entire thing. Then I could pull some of the conduits apart and the couplers, and push and pull it the rest of the way through.
My electrical panel was totally full of course. I combined 4 regular low amperage breakers into 2 tandem breakers, which freed up two adjacent spots for a double pole 50amp breaker.
Once I got all those pieces all installed, I had my contractor come out again. I’d purchased the wrong breakers, and a few of my Tapcons screws had 5/8″ wooden blocks to make them work. He did one more run to Homedepot (on my clock ?) but returned with all the correct stuff. He did breaker switcharoos and connections, and I’m up and running. The breaker install didn’t look too tough. But monkeying around with your electrical panel is no joke. I feel like I did a smart thing hiring that small piece of the job out.
I’m all up and running!