New (to me, anyway) HPWC install with photos

[barrey]

Gave my wife an HPWC I found on Craigslist for her new Mod 3.

Worked with my friend (it's good to have friends who are electricians!) to install it last night.

Parts:
Electrical Supply:
10' each of Red, Black, Green 4 AWG THHN (could have purchased all black at HD or Lowes and used phasing tape)
Murray 60A 2-pole breaker (could have purchased this at HD)

Home Depot:
1 square of 17x17 plywood.
A few fittings and misc such things.

My friend supplied the Liquidtight 1" conduit and the fitting to connect to the top-entry bracket on the HPWC.

A little elbow grease (getting the 3rd 4 AWG through that Liquidtight 90 was a bit tricky)

I used 4 AWG to future-proof it a bit, and also because I couldn't get red-black-green 6 AWG at HD or Lowes, and would have to go to the supply house anyway, so I got 4 AWG as the cost (for 10') wasn't really a factor.

The HPWC I got has a 24' cord so will reach the car in the driveway.

The round charger to the left is an orginal Chevy Volt charger made by SPX that I use to charge my Ford Fusion Energi PHEV.

I got it for free because it was dead. Found out that these have a specific failure mode of the fuses, often due to a defective fuse. Soldered in a new fuse and it's good to go.

Also, the orange NMC (with no firestopping or strain relief) is the wiring done by my solar installers. I'm not a fan.

 

[woodguyatl]

Enjoy it. FWIW, code allows for #10 ground wire for 60 amp circuit. Pulling would have been easier. #8 ground would have allowed full 100 amp circuit.

 

[barrey]

Enjoy it. FWIW, code allows for #10 ground wire for 60 amp circuit. Pulling would have been easier. #8 ground would have allowed full 100 amp circuit.

Yeah, I wasn't 100% sure about that and my electrician pal wasn't available when I was near the supply house, so I went big.

Correct me if I'm wrong, but down the road I think we can replace the breaker with an 80A unit, set the internal switch to that position and charge at 64A (assuming a future vehicle that will make that useful). I have the older HPWC with the rotary switch to select the current.

The question I'm having trouble figuring out is if I could go to a 90A breaker and charge at 72A ?
Assuming 4 AWG THHN, I think we can use the 75 degree column, shows 85 A.
Next-device-size-up rule gives me a 90 A breaker, assuming it's rated for 75 degree terminations.

Not changing anything any time soon, the current setup is fine for the Mod 3.

-Barrey

 

[arcus]

Your current setup (drawing 48A) is the max your car can handle due to limitations of on-board charger:
Onboard Charger

So installing higher amperage breaker will not benefit you at all, unless you plan to install additional HPWC for 2nd car in future:
Load Sharing - TESLA Wall Connector

 

[woodguyatl]

Yeah, I wasn't 100% sure about that and my electrician pal wasn't available when I was near the supply house, so I went big.

Correct me if I'm wrong, but down the road I think we can replace the breaker with an 80A unit, set the internal switch to that position and charge at 64A (assuming a future vehicle that will make that useful). I have the older HPWC with the rotary switch to select the current.

The question I'm having trouble figuring out is if I could go to a 90A breaker and charge at 72A ?
Assuming 4 AWG THHN, I think we can use the 75 degree column, shows 85 A.
Next-device-size-up rule gives me a 90 A breaker, assuming it's rated for 75 degree terminations.

Not changing anything any time soon, the current setup is fine for the Mod 3.

-Barrey

My understanding (not an electrician) 64 yes. 72 no. Continuous load. Wire must be 125% of that needed for intermittent load. 72 x 1.25 = 90 which exceeds the wire rating of 85 amps.

Next size up does not apply to conductors.

 

[barrey]

Your current setup (drawing 48A) is the max your car can handle due to limitations of on-board charger:
Onboard Charger

So installing higher amperage breaker will not benefit you at all, unless you plan to install additional HPWC for 2nd car in future:
Load Sharing - TESLA Wall Connector

Yes, I know we are at max for the M3. That's why my post said "(assuming a future vehicle that will make that useful)".

I'm not changing anything any time soon. Wife loves the M3.
Not getting rid of my Fusion (I just finished some nice mods to the Audio/Nav system, and I don't commute any more).

-Barrey