Sunday, January 5, 2020

DIY Install of Tesla Wall Connector

Tesla has a habit of making the difficult easy, so why should installation of a Tesla Wall Charger (TWC) be any different? Of course it was not, rather this was one of the smoothest electrical projects that I have done (...and I do quite a few every year).

It took me a day to get it all done, start to finish, and that included running almost 50 ft of cables & conduit, securing everything down, making the electrical connections, and configuring and installing the TWC per electrical code requirements.

I would not recommend doing this as a first time electrical DIY, unless you are familiar with NEC and local electrical codes, have obtained a permit and inspection scheduled from you local building authority, and will not electrocute yourself, or worse damage your Tesla .

TWC Installed between garage doors behind my motorcycle parking spot.
This project really started a year before I got my Model 3. I had my heart initially set on a Model S, but decided that I did not want to drive a vehicle on electricity that was produced by the local coal-powered plant. So I decided to get a 7.32 kW solar panel system installed first, since price difference between a Model 3 LR AWS and Model S LR AWD easily pays for a solar setup.

In order to facilitate solar generation, I had to do a DIY install of a 150A sub-panel in the front (far end) of my garage from the main panel, which is walled in and in the basement of the house. After trying and failing multiple times to find an electrical contractor who would do this sub-panel work, it ended up being a DIY project too. My installation passed city inspection with flying colors. This allows for a 40A breaker to be used for the solar converter also installed in the garage and left 110A to be used for other items such a TWC (or maybe even two in the future). 

The quick summary on solar based on 1 year of usage (despite the snow covered panels during winter)  is that we broken even with all the electrical usage of our home as the meter went back to ZERO in 1 year. We have monthly net metering and no tiered billing, so I can pretty much change an eV at any time of day.

Since the ground work was laid with a sub-panel installed, I now had to get power to the back of the garage as close as possible to the Tesla charge port without having TWC cables along the ground at any point. To accomplish this I ran:
  • 3 strands of 6-gauge THHN copper capable of  max 105A at 90C for 2 Hots & 1 Neutral
  • 1 stand of 8-gauge THHN copper for ground.
Three reasons I did it this way were:
  • While the neutral is not needed to the TWC, it is so much easier and cheaper to run it together with others in the conduit than having to upgrade later, especially if I want to switch to a non TWC, plus it was only $45 more worth of cable.
  • Could have gotten away with a much smaller gauges for the Model 3 which only needs a 60A breaker, but at one point the Model S had on board dual chargers which were capable of pulling 72A, thus needing a 90A breaker. There was a possibility that I could have ended up with a used Model S instead of the Model 3.
  • Future-proof for perhaps the model Y or another Tesla or electric vehicle, so  I can switch to bigger breaker and configure TWC load-sharing across two chargers or even install a secondary NEMA 14-50 as a backup to TWC.
For the TWC, I ordered a silver one (as black as sold out) and I was also better of ordering it online and paying local sales tax versus purchasing it in person at a Tesla location in say IL, which has higher sales tax. It arrived in 3 days in a big box. I also got the one with 24ft instead of 6ft cable so I can charge a car father away or even charge a car in the driveway.
Silver Tesla Wall Connector aka TWC box
The TWC was very well packaged into multiple pieces that required very little disassembly to start the install process.
TWC was packaged very securely.
There are multiple mounting options for the TWC available, which is very convenient. The TWC comes in two pieces, this is the optional rear piece and useful when the power cables either come from the top or the back wall, as can be seen by the various rubber grommets that can be removed and/or plugged. There is also a wall plate, which can be used solely with the main unit, which I did not end up using. The rear unit also severs as a good place to loop the cord in case of 24 ft cable option is chosen. No need to buy additiobnal accessories for that.
Optional rear piece of TWC for top and rear power input.
The main TWC unit has an opening on the bottom if the power cables come from the bottom, e.g. a standing post, but this can be plugged if not used using the rubber grommets provided. The unit is very well sealed against the elements.
Bottom opening of front/main TWC unit.
The side view of the TWC which has a holder for the power charging plug. Between being able to loop the cord around the TWC and a holder for the charging plug. Again, not sure why there are so many after market products that do exactly these two functions, which the TWC already does so well.
TWC holder for the charging plug
The first step is to remove the face plate by prying it off at the various tab points to reveal the screws in the front cover of the TWC.
The front is screwed by 6 security Torx screws.
Once those torx security screw are removed, the front cover which has a very good rubber seal can be removed to reveal the inside components. A number of connections have to be made for the front LEDs, the input power and the setting for both the type of power connection and the amperage of the charger.
Insides of a virgin TWC
Once that the TWC was all disassembled ready for installation, I first installed the rear piece on the wall and hooked it up to the power cables. First removed the rubber grommet from the rear piece where the power will come in.
Top opening of the rear piece of the TWC with grommet removed.
I ran the cables in a flexible metal conduit for a total of about 48 ft from the front of the garage, across, over the garage ceiling and then back down the rear. Again NEC and local electrical codes need to be adhered to for wiring, color coding, bracing, clamp distances, etc. My choice of running conduit over the drywall  gives me the flexibility, with minimal work, to remove the entire setup if we ever sell this house and move.
Power run in conduit from front of garage to back in conduit.
Next connection of the conduit and running the power cables through the TWC rear piece and screwing the conduit to the TWC body for a good fit.
Coupling the TWC to the conduit

Then screw the TWC into the studs behind in the drywall for a secure mounting. Connecting the 2 hots (1 to black and 1 to red) and 1 ground cable (to the green) via the terminal block. The neutral cable was taped white as a label, taped off,  and tucked back for any future use.
Connection via terminal block
The manual pretty much easily explains hoe to flip the dip switches. This I am using line-to-line to be 240V with 2 hot, the second diagram is used (Sw 1 down and Sw 2 up). Also the dial switch setting to match a 60A breaker.
Setting the Dip switches and Dial
The setting are made on the TWC dip switches and dials to match my setup.
Optical Illusion in pic. Set DIP SW 1 DOWN, DIP SW 2 UP, DIAL at 9
Fed the red, black and green cables from the block in the rear unit to the front and screwed the front to the back. It was a little tricky getting the red and black cables into the green terminal block but with some patience it was done and secured.
All connections made on the TWC minus ribbon cable for LEDs on cover.
Next step was to shut off the power down the solar converter (this is vital to not die), cut of power to the sub-panel from the main panel and then hooking up the 2 hots, neutral (not used) and ground.
Solar Convertor and Sub-panel ready for connections.

All connections made to the new 60A breaker on the top left of the sub-panel and neutral and ground connections made. Yeah, I need to fix the drywall but its the garage, so whatever. Because of the gauge I ran I can easily upgrade this to an up to 100A breaker in the future,
Sub-panel connections made for TWC with a 60A breaker.
The last connection was the LEDs on the TWC cover via the ribbon cable that behind the white masking tape in the TWC, screwing the front cover back on and snapped the face plate on. Upon flipping all the breakers on the TWC went through its power cycle process and then steady green light in about 2-3 minutes. Plugged my Tesla into  the TWC and it quikcly went up to 48A @ ~240V.  Success! 
Plugged my M3 into newly installed TWC pulling 48A.
It started out at 34mi/hr and in about 5 minutes went to 44mi/hr. Hooray!! I love how the screen shows the charging after the car is exited. Easy to see via the screen.
Charging at max speed using a 240V home AC connection via TWC at 44mi/hr.
It feel so awesome to be able to quick charge at home and never having to take a car to the gas station again.