HPWC Installation - Garage Modifications & Electrical Service

In preparation for my Model S I have undertaken some extensive garage modification. Our primary 2 car garage is attached to our barn which houses 3 additional bays for car storage. The two car garage was serviced by two eight foot wide wooden garage doors with a center post that bifurcated the garage. These garage doors were always a bit too narrow as we have to make a 90 degree right turn into the garage from our driveway. Over the years, a few side mirrors have departed due to operator negligence as well.

When I looked at the specification of the Model S, I quickly realized that it was just about 2" wider than my Volvo XC-60 SUV so a bad situation was going to become even worse. This Spring I inspected the two garage doors which were made of raised panel wood and realized that they had seen better days. So I developed a plan to replace the two doors with one large 17 foot wide door and eliminate the center post. This project started in late March, and with the help of a few friends who were very skilled carpenters, we were able to tear down the old doors, tracks and center post and order an engineered header to support the wider opening. Here is a picture of the work in progress and the finished result.



The next step was the planning for the home charging system for the P90D. Here we had a greater problem... our barn was serviced by an underground branch of 120V 15 AMPs from the late 1930's. Old stuff. Also the span was long and to extend new electricity from the house to the barn would require extensive digging. Disruption of walkways and perennial flower beds would be considered a big negative by my wife and the expense to do so was very dear.

So thinking and thinking I came upon the idea to run a totally new electrical service to the barn complex. Estimates were solicited from 4 electrical contractors and as you would expect responses were all over the place, some being 2X the cost of the others. I went with a young electrician who was the best listener and who had great references from friends.

The plan was a 200 AMP service to a new Square D QO panel. Ground rods would provide ground and the electric company was called in to do a site inspection and approve the service. The electric utility engineer put in a work order to run new wires to my utility pole right near the barn.... here is a picture of that .....



Afterward the electrician contacted the Town Engineer and pulled the necessary permits and then work quickly began.... here are a few pictures of the HPWC and the 14-50R which would be used as a backup should the HPWC ever fail...



The outlets and the 100AMP switch are all Hubble electronics and all work is in conduit.
At present the HPWC is not powered on as we do not have the electricity turned on.
Tomorrow, the Town Inspector will come and inspect the electrician's work and then put in the order for the Utility company to turn on the power....

Much thanks to Forum Member FLASHERZ who helped me with the specifications for the wiring!

What's Next....??

Ordering the P90D in December for a late March Delivery.... Stay Tuned Amigos...

jcaspar said:

Nice update and it will serve you well. I does remind me why I am glad I did my 100 amp panel with two 15-50's myself. I hate all the conduit the electricians like to use and doing it myself I was able to keep every thing run under the drywall.

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In this case, access to the studs in the garage would mean removal of the drywall and then patching, taping and repainting. As it stands now, the industrial look of the conduit is somewhat appealing to me. I may, over time, spray paint it white to match the walls. This particular garage is essentially bare walled other than the old box hanging there near the HPWC. Perhaps I shall install some shelving there to accommodate an array of cleaning and detailing supplies.

Regarding the terminations the electrician is going to be adding conduit internal plastic insulators when he comes today. He just did not have them on the truck.

We cannot test the HPWC as we only are temporarily back feeding the new panel with 110v from the old underground house feed. When the Utility company runs power to the dead head, we can then test the 14-50R and HPWC.

Regarding the cord hanger, I have to figure out where and what to do. Probably will wait until the Model S arrives to find the best spot. We'll see.

Update: the installation just passed inspection by the Town Electrical Inspector! Next step... in a few days or weeks, the Utility Company line service crew pulls service wire from the utility pole to the barn dead head on the new service and installs an electric meter. Then my electrician disconnects & terminates the old 110 underground feed and we turn on the new 200A main disconnect and juice up the panel. We will then be able to put the HPWC into "test mode" as well as the 14-50R.

I was told by the inspector to call the Utility company tomorrow to find out their schedule for the connect. Progress.

Cottonwood said:

If I were you, I would find a couple of Model S owners in your area, at least one with dual chargers, and do a load test. Plug a dual-charger into the HPWC and another Model S into the 14-50. Record the Line Voltage reported by the first Model S to plug in and then record Voltages as both cars ramp up. If you wanted to be really obsessive, you could record the line Voltages as close to the meter as possible to see how the Voltage drop splits between your wiring and the power companies.

BTW, where is the closest transformer and what size is it? Transformer ratings are usually stenciled on the side and are sometimes followed by kVA.

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Yup, we are thinking alike. That plan is well baked already... I will check out the Transformer but the Utility Engineer who did the inspection initially assured me that the transformer which is one pole away is sufficient and fairly new. The wires are all brand new which is nice.