Best plug type for EV charger?

[OliverM3]

cable is clearly marked nm-b

I just need what is code, not what will work.

Code is 6awg thhn with60 amp breaker or 6awg romex nm-b with 50amp beaker so either 48amp continuous or 40 amp continuous.

 

[h2ofun]

Code is 6awg thhn with60 amp breaker or 6awg romex nm-b with 50amp beaker so either 48amp continuous or 40 amp continuous.

Yep, the engineering plans approved, and county, say 6awg thhn 3.4 conduit with 60 amp breaker

Thanks.

I sure would hate to have to file with the contractors board, but would. And they are 100% the letter of the law

 

[h2ofun]

I talked with the county on Friday, and initially was told well it really is not a real issue. I then pushed with data from this group, thanks, and he said he would do more research. He called me back this morning and said yep, the code was what I stated from the comments here.

He than called the installer with a name I gave him and called me back saying they have been busy but plan to fix and I should not have to call
the contractors board. I then called the person and was told yep, they were waiting to hear back from the engineer. I said all folks had to do is give me an update to my emails and phone calls, but oh well.

I asked the county inspector what he would want to see. It was either the emt on the plans, which would be very hard to do, or upgrade the NM to
4/3 stuff, which is real real expensive. Either way their issue, not mine. Sure wish it would have been done right to start with. The only
reason I found this out was because I have been looking into adding EV charging, and what type of wiring that would need.

So thanks group for the technical info!!!

 

[miimura]

Off the top of my head, I can think of:
1. All Teslas except the M3 SR+
2. Rivian EVs
3. Lucid EVs

In the future? Who knows. Better to just future proof your setup so that upgrading is easy. I suspect that most larger vehicles (anything using more than 300-400 Wh/mi) will be getting a > 32A OBC.

4. VW ID.4 (48A)
5. Kia EV6 (48A)
6. Hyundai Ioniq 5 (45A? 48A)
7. Ford Mustang Mach-E (48A)
8. Ford F-150 Lightning (80A)
9. Porsche Taycan (40A)

So, in the top 10 sales in 2022 YTD, only the following cars are limited to 32A AC charging:
A. Tesla Model 3 RWD
B. Nissan Leaf
C. Kia Niro Electric

Q1 2022 Electric Vehicle Sales Leaders

1. Tesla Model Y: 52,051
2. Tesla Model 3: 47,682
3. Tesla Model S: 9,250
4. Ford Mustang Mach-E: 6,957
5. Hyundai Ioniq 5: 6,265
6. Kia EV6: 4,901
7. Tesla Model X: 4,899
8. Nissan Leaf: 4,401
9. Kia Niro Electric: 3,549
10. Volkswagen ID.4: 2,926

 

[tga]

For cars that aren't Teslas though, you'd need to put an adapter on it, which is just as annoying as having to fiddle with a J1772 adapter on the end of a Chargepoint Home or Juicebox.

Not really an issue. I've been charging my S for >5 years on a J1772 plug. I got an extra adapter that lives on the J-plug permanently. I leave another in the car for charging at work

Just hearing one should not run #6 romex on a 60 amp breaker was interesting. Pretty sure that is what they ran, and was speced, on my inverters.

Romex/NM-B cable is limited to the 60deg C rating which, for #6 is 55A. There is no 55A breaker, so code allows you to "round up" to the next largest standard size breaker. But that doesn't allow you to max out the breaker rating; you are limited to the min of wire rating and breaker rating (so 55A load on a 60A breaker w/ #6 romex).

For a 10kw inverter - 10000W/240V = 42A. Add 25% for continuous load: 42A*1.25 = 52.5A, well within the limit for #6 romex. Round up breaker to 60A, which is safe and allowed, since you will never go beyond 42A continuous (equiv to 52.5A intermittent)

I only see some 14-50 ev plug charges but I assume this is just because if was already wired?

Lots of 6-50's, too, eg ClipperCreek. Pretty sure anything they sell with a 14-50 can be ordered with a 6-50 and vice versa.

 

[OliverM3]

Not really an issue. I've been charging my S for >5 years on a J1772 plug. I got an extra adapter that lives on the J-plug permanently. I leave another in the car for charging at work

I do the same I have a chargpoint flex a simple press on the trigger releases the adapter and the J1772 handle from the car as one unit. I even printed a wall hanger that accepts the Tesla adapter in the J1772 handle. Haven't removed the adapter since I got the car. I ordered a spare adapter that I leave in the car.

 

[tga]

I do the same I have a chargpoint flex a simple press on the trigger releases the adapter and the J1772 handle from the car as one unit. I even printed a wall hanger that accepts the Tesla adapter in the J1772 handle.

View attachment 805406

Nice. I keep meaning to print something like that. I'll also add that it's easy to use the adapter. Press and hold the trunk button on the fob to open the door/unlock the port to install. To remove, I just push the J plug's button/latch until the port unlocks, release it to physically lock the adapter to the plug, and IMMEDIATELY yank out the plug and adapter as a unit before the charge port's lock reengages. Easy-peasy

 

[h2ofun]

Not really an issue. I've been charging my S for >5 years on a J1772 plug. I got an extra adapter that lives on the J-plug permanently. I leave another in the car for charging at work


Romex/NM-B cable is limited to the 60deg C rating which, for #6 is 55A. There is no 55A breaker, so code allows you to "round up" to the next largest standard size breaker. But that doesn't allow you to max out the breaker rating; you are limited to the min of wire rating and breaker rating (so 55A load on a 60A breaker w/ #6 romex).

For a 10kw inverter - 10000W/240V = 42A. Add 25% for continuous load: 42A*1.25 = 52.5A, well within the limit for #6 romex. Round up breaker to 60A, which is safe and allowed, since you will never go beyond 42A continuous (equiv to 52.5A intermittent)


Lots of 6-50's, too, eg ClipperCreek. Pretty sure anything they sell with a 14-50 can be ordered with a 6-50 and vice versa.

Lets see with my nm-b #6

I have a 11.4kw inverter, which I am seeing putting out 11.7kw continuous, so thats 11700/240 = 48.75 add 25%, 48.75*1.25= 60.9375, which seems to be above #6 romex? So if you have a 10 kw inverter, great, by at 11.4kw spec, but the app shows going to 11.7kw, seems a no?

Even if 11400/240 = 47.5X1.25=59.375, still above 55amp, right?

 

[OliverM3]

Nice. I keep meaning to print something like that. I'll also add that it's easy to use the adapter. Press and hold the trunk button on the fob to open the door/unlock the port to install. To remove, I just push the J plug's button/latch until the port unlocks, release it to physically lock the adapter to the plug, and IMMEDIATELY yank out the plug and adapter as a unit before the charge port's lock reengages. Easy-peasy

If you need the file I used it's here Tesla J1772 Adapter Charger Plug Holder by grant10k

 

[tga]

Lets see with my nm-b #6

I have a 11.4kw inverter, which I am seeing putting out 11.7kw continuous, so thats 11700/240 = 48.75 add 25%, 48.75*1.25= 60.9375, which seems to be above #6 romex? So if you have a 10 kw inverter, great, by at 11.4kw spec, but the app shows going to 11.7kw, seems a no?

Even if 11400/240 = 47.5X1.25=59.375, still above 55amp, right?

I didn't see the inverter specs in your sig. Solaredge specs 47.5A max output on the 11400, so that's a bit funky w/ #6 romex. But I think solar follows the normal continuous loading rules, ie must be >= 3hrs to be "continuous". AFAIK, EV charging is the only load that MUST be classified as continuous, regardless of duration. So if your inverters don't go above 55A/1.25=44A for more than 3 hours, I believe you aren't subject to the continuous loading requirements.

EDIT - I guess this is just an intellectual exercise, since the installer has said they will fix it. Personally, I'd rather see it done to code than "good enough", especially if your inverters are running at peak output for >3hrs.

 

[Vines]

I didn't see the inverter specs in your sig. Solaredge specs 47.5A max output on the 11400, so that's a bit funky w/ #6 romex. But I think solar follows the normal continuous loading rules, ie must be >= 3hrs to be "continuous". AFAIK, EV charging is the only load that MUST be classified as continuous, regardless of duration. So if your inverters don't go above 55A/1.25=44A for more than 3 hours, I believe you aren't subject to the continuous loading requirements.

EDIT - I guess this is just an intellectual exercise, since the installer has said they will fix it. Personally, I'd rather see it done to code than "good enough", especially if your inverters are running at peak output for >3hrs.

(NEC 705.60.B)
(B) Ampacity and Overcurrent Device Ratings. Inverter
system currents shall be considered to be continuous. The
circuit conductors and overcurrent devices shall be sized to
carry not less than 125 percent of the maximum currents as
calculated in 705.60(A). The rating or setting of overcurrent
devices shall be permitted in accordance with 240.4(B)
and (C).


Therefore I suspect the #6 Romex is undersized for the load of a SE11400

 

[h2ofun]

I didn't see the inverter specs in your sig. Solaredge specs 47.5A max output on the 11400, so that's a bit funky w/ #6 romex. But I think solar follows the normal continuous loading rules, ie must be >= 3hrs to be "continuous". AFAIK, EV charging is the only load that MUST be classified as continuous, regardless of duration. So if your inverters don't go above 55A/1.25=44A for more than 3 hours, I believe you aren't subject to the continuous loading requirements.

EDIT - I guess this is just an intellectual exercise, since the installer has said they will fix it. Personally, I'd rather see it done to code than "good enough", especially if your inverters are running at peak output for >3hrs.

I have yet to get in writing they will fix.

But the county inspector told them it was wrong.

So far the experts here also said it does not meet code. No one has said it has to be 3 hours, even though I am seeing my inverter this time of the year lasting for a while.

What they installed is also NOT what their engineer designed and approved, or the county. So at this point, its not what might be okay, it is
what their engineer and county signed off on, IMO.

Looks like I might be having an electrician coming this weekend to wire my 5 EV stations. I said we need #6 90C thhn wiring in conduit. This is
what the tesla Gen 3 says is needed on a 60 amp breaker.

So wayne on others, is what they installed not to code, or is there another 3 hour spec somewhere?

 

[h2ofun]

(NEC 705.60.B)
(B) Ampacity and Overcurrent Device Ratings. Inverter
system currents shall be considered to be continuous. The
circuit conductors and overcurrent devices shall be sized to
carry not less than 125 percent of the maximum currents as
calculated in 705.60(A). The rating or setting of overcurrent
devices shall be permitted in accordance with 240.4(B)
and (C).


Therefore I suspect the #6 Romex is undersized for the load of a SE11400

Thanks, that is what you folks have all been saying! I will make sure my 5 EV charges are wired correctly.

Now, with the difficulty of my install, this why I assume the first folks use RM #4/3, expensive stuff! So I expect the second installer now
gets to put in 2 long lines of RM #4/3 since no way I believe they could get conduit fulling in. This means cutting lots of sheet rock back out also.

Why would the installer part of a company not install what there engineers speced?

THanks!!!

 

[Vines]

I have yet to get in writing they will fix.

But the county inspector told them it was wrong.

So far the experts here also said it does not meet code. No one has said it has to be 3 hours, even though I am seeing my inverter this time of the year lasting for a while.

What they installed is also NOT what their engineer designed and approved, or the county. So at this point, its not what might be okay, it is
what their engineer and county signed off on, IMO.

Looks like I might be having an electrician coming this weekend to wire my 5 EV stations. I said we need #6 90C thhn wiring in conduit. This is
what the tesla Gen 3 says is needed on a 60 amp breaker.

So wayne on others, is what they installed not to code, or is there another 3 hour spec somewhere?

See my response above. All inverters are continuous loads by NEC definition.

 

[h2ofun]

See my response above. All inverters are continuous loads by NEC definition.

I saw after I wrote what I did. THANKS!!!!!!

 

[tga]

So wayne on others, is what they installed not to code, or is there another 3 hour spec somewhere?

It's in @Vines's post above. Normally loads are only considered "continuous" if they last for >= 3 hrs. EV charging is an exception, NEC 625 says all EV charging, regardless of duration, must be considered continuous. NEC 705.60.B apparently places the same restriction on the inverter output circuit. I'll edit my post.

EDIT: Can't edit post 90, mods won't delete since it has replies. Just ignore that post. Inverter outputs are continuous by definition (NEC 705.60.B)

 

[Vines]

Thanks, that is what you folks have all been saying! I will make sure my 5 EV charges are wired correctly.

Now, with the difficulty of my install, this why I assume the first folks use RM #4/3, expensive stuff! So I expect the second installer now
gets to put in 2 long lines of RM #4/3 since no way I believe they could get conduit fulling in. This means cutting lots of sheet rock back out also.

Why would the installer part of a company not install what there engineers speced?

THanks!!!

Installers are constrained by field conditions. Could be that they didn't notice, couldn't get the correct material, and didn't think it was an issue.

I had an issue where we had run a #10 THWN-2 in EMT for a 35A breaker and a Solar Edge 6000 inverter (25A @240vac)

We had to pull the #10 THWN-2 out (though the wire is rated 35A and install #8 THWN-2 to ensure the circuit was compliant with the NEC. (240.4.D.7)

 

[h2ofun]

Installers are constrained by field conditions. Could be that they didn't notice, couldn't get the correct material, and didn't think it was an issue.

I had an issue where we had run a #10 THWN-2 in EMT for a 35A breaker and a Solar Edge 6000 inverter (25A @240vac)

We had to pull the #10 THWN-2 out (though the wire is rated 35A and install #8 THWN-2 to ensure the circuit was compliant with the NEC. (240.4.D.7)

Yep, no idea why, and 99.999999% of folks would never had found, let alone cared enough to get it fixed. I just know it is going to cost them a lot of money to fix. I sure know the county does not want me to file with the contractors board. I had to do this once. They are 100% black and white, it is either to code or not. I got all of his bond money.

 

[Vines]

Yep, no idea why, and 99.999999% of folks would never had found, let alone cared enough to get it fixed. I just know it is going to cost them a lot of money to fix. I sure know the county does not want me to file with the contractors board. I had to do this once. They are 100% black and white, it is either to code or not. I got all of his bond money.

CSLB reports are pretty serious, so hopefully, the contractor works this out proactively.

 

[STS-134]

Yep, no idea why, and 99.999999% of folks would never had found, let alone cared enough to get it fixed. I just know it is going to cost them a lot of money to fix. I sure know the county does not want me to file with the contractors board. I had to do this once. They are 100% black and white, it is either to code or not. I got all of his bond money.

Well you paid them to do the work to code. They screwed up. They should take this as a lesson to make sure they do things right, and in the future, they won't have to do the work over.