Electric wiring for Car charger

[s0me0nesmind1]

So previous owners of our home had a Tesla and had electric wiring done for a Level 2 charger. Basically from my understanding it's just a matter of installing a new breaker that is 2 110s and running the cables.

Anyhow, previous owner took the wall outlet with them and just left the wires themselves. My problem is that... To me at least, these don't look like 220 wires. These friggen things are ginormous.

There is no way in hell I can wrap these around the screws of the 6-20R outlet that I bought, so I'm guessing im missing something here? Anyone here that is more informed on electrics here that have any ideas?

See pic below, these cables are fat.

 

[Micrornd]

Looks about right.
The Tesla Level 2 chargers I've seen have all had 240vac and 50A requirements, so that wiring would need to be #6's.

 

[s0me0nesmind1]

Looks about right.
The Tesla Level 2 chargers I've seen have all had 240vac and 50A requirements, so that wiring would need to be #6's.

I guess my confusion is based on all the videos I've seen these look SUBSTANTIALLY fatter than ones used for other people making their car charging outlets:

 

[Greenman]

It all depends on the amperage desired at the fixture. An easy way to check is to look at the breaker it's attached to. 50amp requires #6 copper as I recall.

 

[s0me0nesmind1]

It all depends on the amperage desired at the fixture. An easy way to check is to look at the breaker it's attached to. 50amp requires #6 copper as I recall.

So that begs the question... Our car charger is I think... 16 amps. Obviously we don't need this ampage....

My understanding is that amps can always be downgraded, but you can't get more ampage without having the proper ampage at the breaker.

So my question is, can we... basically... convert this #6 cable into a smaller cable that is meant to go with the likes of a 16 amp? Hindsight would tell me that yes - we would just get the smaller copper wire and tie it to the larger.

 

[Greenman]

So that begs the question... Our car charger is I think... 16 amps. Obviously we don't need this ampage....

My understanding is that amps can always be downgraded, but you can't get more ampage without having the proper ampage at the breaker.

So my question is, can we... basically... convert this #6 cable into a smaller cable that is meant to go with the likes of a 16 amp? Hindsight would tell me that yes - we would just get the smaller copper wire and tie it to the larger.

You want to connect the #6 wire to a #12 so it will properly wire into whatever device you're using? If that's what you're asking, yes you can do that, as long as you reduce the breaker to a 20 amp. It's not good practice, and most electricians would slap you for it, but it's safe as long as the breaker is sized for the smallest conductor you're using.

 

[s0me0nesmind1]

You want to connect the #6 wire to a #12 so it will properly wire into whatever device you're using? If that's what you're asking, yes you can do that, as long as you reduce the breaker to a 20 amp. It's not good practice, and most electricians would slap you for it, but it's safe as long as the breaker is sized for the smallest conductor you're using.

So better way is to just ask this - what would you do in this case?

I really don't want to have to re run a wire or anything if at all possible, and am ultimately just seeking the easiest solution for us to be able to use our level 2 charge cable.

I guess another option would be to return the level 2 charging cable I bought and instead buy another one that is rated for higher amps?

 

[PowerEngineer]

The size of the wire has virtually no effect on the current that flows through that wire; it is really all about the demands of the load that the wire is connected to. Larger wires are ALWAYS better than smaller wires because they have less resistance (resistance being inversely proportional to the wire's cross sectional area) which means lower resistive losses and therefore less concern over melting insulation or fire starting. You never need to change out a bigger wire for a smaller wire. I suggest that you stick with the wire size that you have.

 

[Greenman]

So better way is to just ask this - what would you do in this case?

I really don't want to have to re run a wire or anything if at all possible, and am ultimately just seeking the easiest solution for us to be able to use our level 2 charge cable.

I guess another option would be to return the level 2 charging cable I bought and instead buy another one that is rated for higher amps?

I'd install the larger charger. Determine exactly what wire size you have and that will tell you what size charger you can use.

btw. I'm Hammerhead over at the Kingdom of Crap.

 

[Micrornd]

You mention a Level 2 charging cable and a 20A receptacle, and then mention returning the Level 2 charging cable for one that is rated for more amps?
NONE of that goes together.

The smaller wiring, you have seen, is used with Level 1 chargers, as they are 120vac 20A.

As others have suggested, keep the wires you have, that way you can still use them if you decide to step up to a Level 2 charger later.

Unless you are truly familiar with 120/240vac wiring,(especially since the above mentioned statements sound like you are ?confused?) I recommend you have an electrician make the connections,
since you are converting from 120vac to 240vac if you install a level 1 charger, although a Level 2 charger is what I would recommend for convenience.
Going from 120vac to 240vac means some rewiring in the breaker panel and changing of breakers is required as well as the connections at the charger end.

Remember your homeowner's insurance is void (in virtually all policies) if changes are made to your electrical system by anyone other than a licensed electrician.

 

[herm0016]

if you are confused, call an electrician.

they should have run a neutral with the 2 hots and a ground, and they should have used properly colored wires, it was a bit of a hack job to begin with. i know its ok with code to tape the color, but i still don't like it. If you are unfamiliar with this stuff, get a professional. it should only cost a few hundred to get that fixed up properly.

 

[bigi]

Home Charging Wiring Guide

This guide explains some of the choices you and your electrician will make in creating a safe way to charge your Tesla. While we don’t recommend you do the work yourself, it is smart to understand the various choices and what they mean. (Nov-2023 update)Charging Speed CalculatorRecommendations -...

teslatap.com

Wires GA is based on current those are supposed to carry.

What is their gauge? It probably was some of NEMA outlet.

 

[Scarpozzi]

if you are confused, call an electrician.

they should have run a neutral with the 2 hots and a ground, and they should have used properly colored wires, it was a bit of a hack job to begin with. i know its ok with code to tape the color, but i still don't like it. If you are unfamiliar with this stuff, get a professional. It should only cost a few hundred to get that fixed up properly.

I recently added a few 30amp 220 lines to move an electric dryer to the other side of the room and for a mini split. I ran a brand new line in both cases even though I could have gotten away with the 10-2 the dryer was on, I opted to run a brand new line for $70 from the breaker to put it on 10-3 and upgrade the recepticle to a 4 prong plug.

I agree with herm0016...pay an electrician if you want peace of mind and to make sure it's done the right way. If you don't have any specialized car charger places since it's such a niche market, you could always call around the hot tub stores in your area and ask for electrician references. Those places will know who does a lot of work with 50amp circuits and likely stock parts on their trucks beyond 30amps.

I also agree with Greenman about the bigger charger. Higher amperage may provide faster charging...bigger wire will mean you're far less likely to having issues with overheating wires. You'll also be positioned for replacing the system in the future since those electronics likely have a shorter lifespan than anyone will admit.

 

[BoomerD]

How far from the breaker box is the charger connection? Larger wire sizes can be needed to help reduce...voltage drop...if the run is longer than what would be acceptable for smaller wires...
(I'm probably not splainin it right...)

 

[deadlyapp]

As others have said, the key reason for larger gauge wire is resistance and heat generation over the run. Yes, you can certainly push 50A through a 16# wire but you'll fry the entirety of the thing. Similarly, while 8# might be fine for 50A across 25 ft or so, at 50 ft you probably want to go to 6#.

I don't know much about the car charger specifically, but for the 50A 220 breaker I just put in I used 6/3 for about a 50ft run. Hooking up to the breaker is simple if the wire is already terminated there. Make sure your overall house breaker is still sized appropriately, especially if you expect that this + air conditioning + other large current draw appliances may operate together.

 

[s0me0nesmind1]

You mention a Level 2 charging cable and a 20A receptacle, and then mention returning the Level 2 charging cable for one that is rated for more amps?
NONE of that goes together.

The smaller wiring, you have seen, is used with Level 1 chargers, as they are 120vac 20A.

As others have suggested, keep the wires you have, that way you can still use them if you decide to step up to a Level 2 charger later.

Unless you are truly familiar with 120/240vac wiring,(especially since the above mentioned statements sound like you are ?confused?) I recommend you have an electrician make the connections,
since you are converting from 120vac to 240vac if you install a level 1 charger, although a Level 2 charger is what I would recommend for convenience.
Going from 120vac to 240vac means some rewiring in the breaker panel and changing of breakers is required as well as the connections at the charger end.

Remember your homeowner's insurance is void (in virtually all policies) if changes are made to your electrical system by anyone other than a licensed electrician.

if you are confused, call an electrician.

they should have run a neutral with the 2 hots and a ground, and they should have used properly colored wires, it was a bit of a hack job to begin with. i know its ok with code to tape the color, but i still don't like it. If you are unfamiliar with this stuff, get a professional. it should only cost a few hundred to get that fixed up properly.

Thank you thank you -

I think I am definitely understanding better based on all the useful replies here.

I think one of the keys for me to illustrate for you guys though is... Regardless of the fact that things are a "Level 2" charger or not, the amps on the respective charger can vary.

All of the below chargers are compatible with our vehicle - and I've seen mass variety in amps. So it sounds like it's just a matter of matching up the amps of the cables with the amps at the breaker. The concept of being "Level 1" or "Level 2" (or more specifically 110 vs 220) doesn't really matter.

Again ... unless I'm misunderstanding.

 

[s0me0nesmind1]

How far from the breaker box is the charger connection? Larger wire sizes can be needed to help reduce...voltage drop...if the run is longer than what would be acceptable for smaller wires...
(I'm probably not splainin it right...)

Breaker box is literally on the other side of the outlet (with slight variation in location).... But yeah, it's not down the hall and 2 doors down or anything.

 

[herm0016]

we have a plug in car.

the car will dictate the amps (current). install something that will handle a higher current than the max the car will use. i just install nema 14-50 outlets and wiring to handle 50 amps every time i do a project for something 220v, that way whatever i want to plug in, in the future, it will be good to go up to 50 amps. our car only pulls 16 amps max, still have a 50 amp outlet in the garage to plug it into.

The device (car) will only use the amount of current it needs, not the max for the outlet or the charging cord. What is the maximum amperage your car will charge at? get a charge cord that will supply at least that much current, and wire the outlet to supply at least that much current.

your "charger" is only an extension cord with some protection circuits, it is supplying the 220 volts directly to the car. The actual device that charges the battery, and converts that to DC current is installed inside the car.


call a damn electrician. have them wire up a plug that you can plug the charge cord into. that way when you leave, or you want to upgrade or whatever, you just un plug and plug in the new one.

 

[Red Squirrel]

This was done very wrong unless there's something completely different about how EV chargers work that I'm not aware of. There's suppose to be 2 hots, a neutral and a ground (most likely needs to be insulated to prevent galvanic corrosion). Though it MIGHT be permitted to use the EMT as ground... but still there should be a neutral. I have a feeling they are using the EMT as the neutral and that is wrong. Looks like you got 3 hots there? Is 3 phase delta service? If it is then that's beyond what I'm familiar with but it's probably done right and you'll need a 3 phase rated charger.

Honestly if I got an EV I'd probably just use a standard 120v cord most of the time myself instead of messing with proprietary plug formats. Slow charging is also less hard on the battery. Supercharging when you're traveling is one thing, but when you just went to work and back or ran errands, it's not like you'll be at 0 charge when you get home. You just need a top up charge and 8 hours overnight is more than plenty.

Actually I just noticed the green tape, so guessing that's the ground. I guess there's no neutral as they are just using 240 only? It might be alright then assuming the charger does not need 120v for anything. (auxiliary circuits etc)

 

[herm0016]

This was done very wrong unless there's something completely different about how EV chargers work that I'm not aware of. There's suppose to be 2 hots, a neutral and a ground (most likely needs to be insulated to prevent galvanic corrosion). Though it MIGHT be permitted to use the EMT as ground... but still there should be a neutral. I have a feeling they are using the EMT as the neutral and that is wrong. Looks like you got 3 hots there? Is 3 phase delta service? If it is then that's beyond what I'm familiar with but it's probably done right and you'll need a 3 phase rated charger.

there should have been a neutral, but the rest of that is totally incorrect.

 

[s0me0nesmind1]

This was done very wrong unless there's something completely different about how EV chargers work that I'm not aware of. There's suppose to be 2 hots, a neutral and a ground (most likely needs to be insulated to prevent galvanic corrosion). Though it MIGHT be permitted to use the EMT as ground... but still there should be a neutral. I have a feeling they are using the EMT as the neutral and that is wrong. Looks like you got 3 hots there? Is 3 phase delta service? If it is then that's beyond what I'm familiar with but it's probably done right and you'll need a 3 phase rated charger.

Honestly if I got an EV I'd probably just use a standard 120v cord most of the time myself instead of messing with proprietary plug formats. Slow charging is also less hard on the battery. Supercharging when you're traveling is one thing, but when you just went to work and back or ran errands, it's not like you'll be at 0 charge when you get home. You just need a top up charge and 8 hours overnight is more than plenty.

Actually I just noticed the green tape, so guessing that's the ground. I guess there's no neutral as they are just using 240 only? It might be alright then assuming the charger does not need 120v for anything. (auxiliary circuits etc)

Weird - All the Youtubes and guides I saw said there would be 2 hots and 1 ground - which matches what is there?

 

[Red Squirrel]

Weird - All the Youtubes and guides I saw said there would be 2 hots and 1 ground - which matches what is there?

Hmm maybe it's the way it is then. Normally with a 240v circuit there's a neutral too but guess it's different for EVs. They really should have used an actual green wire for the ground though. That darkish tape is kind of a hack. At first I didn't even see it and thought it was 3 hots. Colours matter, because when you get to the panel you need to connect it right.

 

[NutBucket]

Huh, I thought I replied to this earlier but I don't see my post? Anyway, 2 hots and a ground is correct for single phase 220V. Neutral is only necessary for two phase power.

It's not the cleanest look but so long as you use the proper color tape to mark both ends of the wire it meets code. I've done that to convert a 220V circuit to 120V. I keep a roll of white electrical tape in my electrical toolbox.

 

[drnickriviera]

there should have been a neutral, but the rest of that is totally incorrect.

Why do you think that? What purpose does the neutral serve in a 240V circuit? There's no load imbalance like a multiwire branch circuit correct? or is it just an extra safety? Internal short where ground should only be for a chassis ground?

I agree with you on the nema 14-50. Just install a surface mount box with that, then make a pigtail to go to the level 2 charger. Level 1 charging on an EV is an effort in futility

 

[herm0016]

Huh, I thought I replied to this earlier but I don't see my post? Anyway, 2 hots and a ground is correct for single phase 220V. Neutral is only necessary for two phase power.

It's not the cleanest look but so long as you use the proper color tape to mark both ends of the wire it meets code. I've done that to convert a 220V circuit to 120V. I keep a roll of white electrical tape in my electrical toolbox.

a lot of modern 220 v appliances and other things use 120 volts from one hot to neutral for their control circuits. best practice is to run 4 wire. I know my stove and dryer both require it to work. I believe it is also code now to run them as 4 wire circuits.

"single phase"? 220 is always 2 "phases", its 2 120 lines 180 degrees out of phase, so you get 220 between them, and 110 between each of them and the neutral or ground. but don't confuse this in any way with a 3 phase system for industry. your house is running off of one transformer and one phase from the power company. your 110/220 is made in the transformer.

for industrial 3 phase, there are 3 transformers and 3 phases from the power company.