Quick question.. I searched all the Tesla forums and just wanted to confirm a few things..
Will be getting a HPWC and I currently have a NEMA 14-50 with a 50amps breaker.
I would like to replace the outlet with the HPWC, hardwired if possible since I want the 60amp breaker and 48amp max charge.. if I pigtail into the outlet it won't go above 40amps charging.
What do I need to check cabling wise with the electrician who did the outlet so I know if the cabling needs to be "ugpraded" or if I can simply cap off the white cable and get the HPWC hard wired?
Also for the breaker is it possible to swap it to a 60amps ? Or I'm missing something here.
FYI I'm getting solar and getting a 225A panel so I will have plenty of space in my new panel (coming from 125A).
Thanks!
(oh and please no philosophical discussions about NEMA 14-50 being enough etc., I'm getting a free HPWC !)
So what matters is the ampacity of the wire and what type of wire it is (and what if any conduit it is in).
likely need a higher gauge wire (4?) to support the 60 amp circuit and a new 60 amp breaker in the panel. (The latter is cheap.)
No, this depends on what kind of wire and if it is in conduit. I have #6awg in conduit which is good to 65 amps. I have it on a 60a breaker.
FWIW 3 gauge copper for a 90/100 amp circuit is $1.02 per foot from Home Depot, 2 big ones needed and can probably use one of the existing wires if THHN as the ground.
Breaker will be $20-30 more than a 60amp.
You are already spending money to upgrade might as well future proof I think you will find the cost difference minor.
3 AWG copper in conduit is good to 100 amps. If your conduit is large enough and your new service has enough capacity then this would be the most optimal setup for a HPWC for whatever the future may hold (a M3 can only take up to 48a which needs a 60a breaker). It would support up to 80a continuous.
You need to know the gauge of the wire & type (romex or THNN in conduit), Distance would also be interesting if it is a long distance.
You could probably just ask the electrician that wired the 14-50 if it is capable of handling 60A w/o replacing the wiring?
You would likely want 4ga wiring for a 60a Circuit.
6 gauge in conduit is fine for a 60a circuit.
You guys are awesome
I came back tonight and looked at my panel, and this is what is written to the best I could tell in the dark, it seems like it is saying Southwire 3 AWG THHN - this is the red wire, there was a white and black as well all same size.
That's not big enough for 60amps right?
Also the run from panel to other side of 2 car garage is roughly 40 feet long, with a few "shoulders" so not sure if that's an important factor for going to bigger size wire (I remember the electrician saying they can't bend much more the wire).
The problem with using the solar electrician is I will be getting the HPWC after they do the panel upgrade..
As others have noted, that really does not look like 3 AWG. 8 AWG is more likely. 8 AWG in conduit is good to exactly 50 amps (40a continuous) so that makes sense.
The important thing we need to know is how large the conduit is from the breaker panel to the receptacle? Is it EMT style conduit? Can you post a picture? This will dictate the largest wire you can run in that conduit.
Looks like Copper 3 AWG is good for at least 80 Amps, if not 100.
http://www.usawire-cable.com/pdfs/nec ampacities.pdf
100a if installed in conduit. (80a continuous)
Ampacity Charts
I'm pretty sure that's 8 AWG, not 3 AWG. So it would be good for 55A max, or 44A delivered to the car. You'd need 6 AWG THHN in order to support a 60A circuit with 48A delivered to the car.
No. You can't read the 90c column. The HPWC or receptacle and breaker are nearly guaranteed to be rated to 75c, so that is the limiting factor.
Cool, a wire like this one?
Southwire (By-the-Foot) 6 Black Stranded CU SIMpull THHN Wire-20493399 - The Home Depot
So roughly 40 feet of wiring, 2 wire (black and red, no need for white right)? And a ground wire or not needed?
At 84cents/foot, 2 wires X 40 feet that's $67 of cables, and a 60 amps breaker seems to be about $10.
Great idea! And could they install the 60 amps breaker too in the panel, or should I leave the 50amps? I.E. would NEMA 14-50 work with 60amps over 6 AWG THHN wire?
Yes, #6 awg copper THHN in conduit is fine on a 60a breaker which will give you 48a continuous for your HPWC. You might technically be allowed to use the conduit as the ground, but I would recommend running a dedicated ground. You need a 10awg for up to a 60a circuit. Up to 100a needs 8 AWG.
You can't upgrade the breaker to 60a even if you upgrade the wire as you are not allowed to put a breaker over 50a on a 14-50 receptacle.