I am in the process of finishing my basement and before the drywall ceiling is put up, I would like to run a wire from my breaker box to my garage to support an EV charging station in the future. Does anyone have a recommendation as to what gauge wire I should run?
What gauge wire for EV charging station?
- Thread starter barlowc
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Wire run
Main charger wire needs to be a 4 conductor 6 gauge wire.
This can be run to a NEMA 14-50 socket, a NEMA 14-30 socket, or hardwired.
If using a NEMA socket, remember, the 14-50 is rated at 50 amps, but you can under size the breaker for safety. (20, 25 or 40 amp, rather than 50)
The NEMA 14-30 is rated for 30 amps, so a 20, 25, or 30 amp breaker can be used.
Hardwire-match it to the recommended breaker
if you have one more open space in the fusebox, I would also run a 10 gauge 3 conductor wire for a 20 amp, 120 volt, dedicated circuit. I would use a plain 20 amp, 120 volt breaker, but run it to a Weather Resistant 20 amp GFCI.
This is for charging with the on-board charger, just in case.
Main charger wire needs to be a 4 conductor 6 gauge wire.
This can be run to a NEMA 14-50 socket, a NEMA 14-30 socket, or hardwired.
If using a NEMA socket, remember, the 14-50 is rated at 50 amps, but you can under size the breaker for safety. (20, 25 or 40 amp, rather than 50)
The NEMA 14-30 is rated for 30 amps, so a 20, 25, or 30 amp breaker can be used.
Hardwire-match it to the recommended breaker
if you have one more open space in the fusebox, I would also run a 10 gauge 3 conductor wire for a 20 amp, 120 volt, dedicated circuit. I would use a plain 20 amp, 120 volt breaker, but run it to a Weather Resistant 20 amp GFCI.
This is for charging with the on-board charger, just in case.
Consult with you electrician because every installation is unique. Distance from the main panel is also one of the prime determinants in a safe installation. Internet hacks like us on this board can only give you generalizations.
In general, thicker wire is better. Many install instructions recommend a #3 gauge or thicker (smaller number), however, thicker wire comes with a tradeoff in higher cost.
Also, if you're planning for the future and the likelihood that a next generation charger will consume more power, thicker wire will be required for that as well.
Good luck.
In general, thicker wire is better. Many install instructions recommend a #3 gauge or thicker (smaller number), however, thicker wire comes with a tradeoff in higher cost.
Also, if you're planning for the future and the likelihood that a next generation charger will consume more power, thicker wire will be required for that as well.
Good luck.
#6 wire, 220 V 50 Amp breaker. I would hope your main breaker is 200 Amps. If it isn’t I’d recommend consulting with an electrician.
I have a 14-50 outlet i put in the corner of my garage for my camper, welder, and generator back feed. Two legs of #6 each on a 50 amp breaker , and a neutral, and a ground of course.
I’m thinking that it boils down to a 120 V charger or a 220 V 50 amp charger. There is such an animal as a 440 V charger but that would be a specially built public charger. About that, I’m not sure what Tesla has in mind.
I’m thinking most modern homes have a 200 amp service. Older homes with 100 amp service are gong to have a tougher time with a 50 amp car charger.
I’m thinking most modern homes have a 200 amp service. Older homes with 100 amp service are gong to have a tougher time with a 50 amp car charger.
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That's good advice. I know standard 6.6 kw rated L2 public chargers use 10 gauge wire in the cord that goes to the car. I assume there is a 30 amp fuse inside the charger. One I go to has 30 amp switch boxes feeding each station. The cords get quite hot, especially since the public finds ways to put sharp kinks in them. I can't figure out what they are doing to kink the heavy cable like that. But they do it. If an outlet is 50 amp rated, the circuit breaker should be 50 or less, and so on. Like you say it can even be less like a 20 amp.
Does a 220V charger really need a neutral?
I ran 50' of #6 from the 200A panel to a NEMA 14-50 in the garage for the 2018 Model 3 Mid Range (no longer available).
A Tesla Wall Charger could easily be added, but there is no benefit for our car as it can pull a maximum of 32A.
The Long Range cars can pull more, but is a Wall Charger really necessary? Probably not.
The #6 wire was almost $200 as I recall.
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The 14-50 outlet will be more useful with a neutral. You can generator backfeed the house as i do ( flamesuit on), run an rv with the right adapter.
If you're installing a cable with a neutral, upsize it a bit and install a subpanel. The correct outlet for a 220V device which needs no neutral is a NEMA 6-50; it would not be correct to install a 14-50 with no neutral.
I would (and did) use aluminum SER cable for this. Copper is expensive and rarely used for heavy gauge cables, at least in residential work.
JHZR2
Staff member
How long is the run? Probably the best thing is as big as possible, to minimize voltage drop and allow for higher rate charging in the future. That said, I’d have to wonder if it will be practical/common to do more than 50A in residential settings.
Figure out the length of the run, then use an ampacity chart to figure out the right conductor size.
Figure out the length of the run, then use an ampacity chart to figure out the right conductor size.
What home chargers go beyond Level 2? Level 2 wall chargers have 10 gauge wire for the charging cord. On all the public chargers I have seen. That would be the weakest link. A 30 amp two pole breaker would take care of it. Not up on all the home charger options.
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Sorry, this is the wrong place to ask that question.
Call up an electrician so you don't set your house on fire.
Call up an electrician so you don't set your house on fire.
Well said. I was lucky enough to have a union electrician come and do my installation on his spare time.
You don't wanna get this wrong.
Well the well known licensed electrical contractor who did the wiring on my house, passing city inspections with permit, wired the three way switches wrong and when I went to change a light bulb I got electrocuted up on the ladder. Nice big jolt. I had to do the wiring correctly myself. With a whole lot of cussing.
What about your electrician using the 60 breaker on #6 wire and the outlet is rated 50? I would say it’s incorrect even if in the code somewhere it is allowed.
I am not sure if the breaker was 50A or 60A. Maybe he said he would have to replace the breaker if we installed the Wall Charger later...
The Wall Charger uses a 60A breaker.
Maybe I will take a look at the breaker.... Thanks for your post.
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