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HPWC issues

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#6 is 75A at 90 degC, which derates to 60A ampacity per 310.15(B)(3)(a). #14 is 25A at 90 degC, which derates to 20A. 75 degC termination ratings apply at the breaker and appliance terminals, but that's 65A for #6 and 20A for #14 (310.15(B)(16)).

1" provides plenty of space; it's the minimum size for 3x#6 (HPWC) + 2x#14 (120V) + 1x#10 (ground). If you only pull hots for the 60A circuit (and no neutral), you can even use a 3/4" conduit.

You may share a single ground (not neutral!) but it must be sized for the largest circuit. 60A requires #10 ground.
The 1" conduit is in place.
I would pull up to #3 gauge (and appropriate ground, no neutral) for the HPWC, and #14 for the 20A. Question was about the derating due to the multiple circuits in the same single 1" conduit. Don't we hit a limit before the 100A level, because of the second circuit?

And I am getting all electrical work permitted and inspected, even though this stance is severely delaying my kitchen remodel!

Rick
 
The 1" conduit is in place.
I would pull up to #3 gauge (and appropriate ground, no neutral) for the HPWC, and #14 for the 20A. Question was about the derating due to the multiple circuits in the same single 1" conduit. Don't we hit a limit before the 100A level, because of the second circuit?

And I am getting all electrical work permitted and inspected, even though this stance is severely delaying my kitchen remodel!

Rick

Okay...

First the bad news - you'll need to use #2 if you want a 100A HPWC setting. #3 THHN @ 90 degC is 115A, derated for the additional circuit in the conduit you're limited to 92A. So you couldn't use the 100A setting with #3 if the 120V circuit were in the same conduit.

Ground moves up to #8 for a 100A circuit.

Now the good news - you can fit 2x#2 + 2x#14 + 1x#8 (ground) in a 1" conduit, except schedule 80 PVC which requires 1 1/14". I use the calculator here: Raceway Fill Calculator
 
Okay...

First the bad news - you'll need to use #2 if you want a 100A HPWC setting. #3 THHN @ 90 degC is 115A, derated for the additional circuit in the conduit you're limited to 92A. So you couldn't use the 100A setting with #3 if the 120V circuit were in the same conduit.

Ground moves up to #8 for a 100A circuit.
Not that bad, as I would still be happier with 80A over #3 (and charging at 64A) than I would wrestling #2 cables into a HPWC.
 
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Not that bad, as I would still be happier with 80A over #3 (and charging at 64A) than I would wrestling #2 cables into a HPWC.

*shrug* It's only about 15 minutes of cursing, after that - smooth sailing from there on out. :) My HPWC is using #2.

You're good in a 1" conduit of any type for both circuits for 2x#3+2x#14+1x#8.
 
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*shrug* It's only about 15 minutes of cursing, after that - smooth sailing from there on out. :) My HPWC is using #2.

You're good in a 1" conduit of any type for both circuits for 2x#3+2x#14+1x#8.

I agree completely! Although I normally charge at 56 Amps, being able to crank it up to 80 Amps when I want a faster charge rate is very useful.

This post has a great picture of how to do a 270˚ bend in the #2 wire to make your life a lot easier than trying to do the tight 90˚ bend inside the HPWC: HPWC install: 270˚ bend inside the HPWC
 
I agree completely! Although I normally charge at 56 Amps, being able to crank it up to 80 Amps when I want a faster charge rate is very useful.

This post has a great picture of how to do a 270˚ bend in the #2 wire to make your life a lot easier than trying to do the tight 90˚ bend inside the HPWC: HPWC install: 270˚ bend inside the HPWC
it is great, but isn't that a pic of a 270˚ bend in #3 wire? Yes, that's how I'll do either gauge, and use the side entry like that. Will try not to pinch the purple signal wire too.

Well well well... Turns out the 270 bend was not a gread idea. The red wire (mine) was pinching the small purple signal wire against the exposed part of the 240V cable that gets to the car.
...
Any one needs a HPWC with a blown PCB ? :D

Aaaaand my house service may need an upgrade before I get to use a full 80 Amps anyway!
 
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HPWC Thermal Performance.jpg


If you don't need the full juice to speed your charging, I am betting that life will be better with just 60 amps max, instead of 80 amps. Here is photo of my 80 amp setup showing how hot things get: