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number12

Active Member
Supporting Member
Aug 16, 2016
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Tesla
Trying to save some time and have materials ready for electrician.

What materials are needed to install HPWC if your garage breaker has plenty of room and is newish (2007 Siemens)

100AMP breaker
3awg copper wire in whatever length necessary

Electrician should have rest?

TIA
 
Pre-determine the entry point of power into the HPWC, mine had a rear or side choice. The power line is very thick and stiff and can only bend in an arc of maybe a 2 foot diameter circle. Walk the path and mentally peg where that sucker is going to get routed from panel to unit.

The cable is tacked along the wall on studs. Clear the path. Mark the studs.

You need a specific diameter hole saw to cut a hole in side of HPWC to bring heavy power line into the side of the unit. You can only go in one side (left) of the unit and not the other. You could drill it out in advance for the electrician. He would appreciate that. If you don't drill into the guts an cables inside the unit. So do it right.

You need a stud to mount HPWC on the wall, or if on concrete, then use concrete anchors. If you have no stud, you need to mount a piece of plywood. Use 3/4" thick plywood. Prepare the site. Measure, mark... etc. Put your own anchors in, that's a pain for electrician.

These things trim time, if you're being billed by the hour and you value your time less (or want a certain quality / care put into those things).

Let the electrician source the electrical materials, they get it cheaper than you.

Definitely let them torque the nuts down on wire lugs, they'll use the appropriate lube at all needed connection points, and don't mess with those after the job is done. It's a lot power flowing (a whole house worth) and you don't want these connections heating up if disturbed. Call an electrician back if you need to do anything with the power supply line, or it's connections in the future.
 
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I agree that installation should have everything other than carpentry and should know code for inspection of conduit, insulation, installation clearance, etc. As for cheapest or best materials, it's up to you to stipulate the quality or the installer will use "best profit" practices. : )
I think 90A breaker is applicable to 72A charging. 100A only if you have a newer vehicle with dual 40A onboard capable of 80A draw.
It occurs to me that Tesla describes the wall connector as an 80A device, so it seems appropriate to provide a 100A circuit and it may be capable of drawing a peak 80A if only outputting a peak 72A to the vehicle. The documentation does show a 90A dip switch configuration, but this may be simply to accommodate the scenario of a 90A supply breaker.
Is there a Tesla capable of drawing more than 80A peak? I assume the new P100D is still 80A.
If the given tradesperson hasn't done an installation, they'll want to see the initial test procedure diagnostics and dip switch configuration.
Otherwise, there's no mystery, just be sure to use high quality, low loss copper conductors (not aluminum) to avoid a meaningful loss that can translate into actual dollar over time.
 
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Don't forget wall art.:)
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