Electrical people. Opinions on this L2 Install?

[Zoidz]

Not sure why some people were recommending 6/3. You only need the two hots. No neutral is needed.

My electrician ran 6/2 70 feet with a 60A breaker to a hard wired charger that will be charging at 48A.

Future proofing. It is not much more expensive to run 3 conductor the first time - same labor for either. It's expensive to replace 2 conductor with 3 conductor.

Examples:
- Manufacturer XYZ releases a V2H system that for whatever reason requires 120 VAC.
- In the future you want/need to add a subpanel for some other project/device to feed a 120 VAC circuit in addition to the EVSE from the subpanel.

Sponsored

 

[dradam]

A lot of good information here so I would only add some future proofing comments.

In this era of ever evolving batteries and EV's, and while you are already running cable, I would run something large enough so that you can have a true sub panel in your garage area. You would then be able to run whatever (mainly) you like from that and it may offer you space for future circuits or a more powerful charger in the future. I would opt for two hots a neutral and ground. While most chargers don't need a neutral it is possible that they may in the future and much easier to run now than later.

6 AWG romex will not get you to 48A by code, but 6AWG can be purchased already in a flexible metal conduit and can get you to 48A if needed (and indoors).

I charge overnight at about 25A, but it is nice to know that I can charge faster if needed.

Hope this helps, show us your install when completed !

 

[Zoidz]

My understanding is that you cannot run NMB in the open (as in, exposed along a wall). It can be in the wall, or in conduit if on the outside wall, but that conduit if it holds NMB can't be in an wet/damp location. I'm not sure how garages factor into wet/damp. So I realized this reply is probably not helpful at all

That's not correct. NMB can be run in the open. The problem is the extremely vague 334.15(B) which requires protection "where necessary" (?) and leaves huge leeway to the inspector, leading to arbitrary (depending on where you are and who you ask) "7 foot", "8 foot" and "10 foot" rules meaning if it is above X feet, it is "unlikely" to be subject to physical damage. If you can convince the inspector it's not subject to physical damage, per NEC it can be exposed if it does not violate other parts of the code. However, some local codes may be more specific about this.

 

[babock]

Future proofing. It is not much more expensive to run 3 conductor the first time - same labor for either. It's expensive to replace 2 conductor with 3 conductor.

Examples:
- Manufacturer XYZ releases a V2H system that for whatever reason requires 120 VAC.
- In the future you want/need to add a subpanel for some other project/device to feed a 120 VAC circuit in addition to the EVSE from the subpanel.

I will take my chances that I will ALWAYS be able to get an EV charger that doesn't need a neutral.

 

[dradam]

I will take my chances that I will ALWAYS be able to get an EV charger that doesn't need a neutral.

If the op decides on a subpanel it will require a neutral regardless and could be used or ignored from there.

 

[Supratachophobia]

Copper #6 NM-B (Romex) is only rated for 55 amps non-continuous load, de-rate that by 20% for continuous loads, and you're now at 44 amps, so set your EVSE at 40amps and sleep well at night. For the small price diff between #6 and #8 THHN from the shutoff to the EVSE run, I'd keep it all #6 for safety... installing a 50 amp breaker on 55amp rated #8 THNN is cutting it kind of close if something shorts out that #8.

Ehhh, I think there's a provision to round up or we are missing something. If not, every Tesla HPWC in the last 10 years would be in code violation.

 

[babock]

If the op decides on a subpanel it will require a neutral regardless and could be used or ignored from there.

I guess I missed his post where he was putting in a sub panel.

 

[Supratachophobia]

Thanks everybody.
Wire needs to be snaked through multiple walls and ceilings and I'm trying to cut as few holes in the sheetrock as possible. so will probably stick with the Romex. I'll suggest 6-2 over 6-3 because I'm guessing it smaller and tighter bending.
40 amps is fine. I just figured why not get 48A if it's easy.

I always suggest 6-3 just in case you ever need the neutral for a sub panel. Cheap insurance compared to re-running.

 

[babock]

I always suggest 6-3 just in case you ever need the neutral for a sub panel. Cheap insurance compared to re-running.

If you are putting in a sub panel, you might as well run something much bigger than 6

 

[Supratachophobia]

That's not correct. NMB can be run in the open. The problem is the extremely vague 334.15(B) which requires protection "where necessary" (?) and leaves huge leeway to the inspector, leading to arbitrary (depending on where you are and who you ask) "7 foot", "8 foot" and "10 foot" rules meaning if it is above X feet, it is "unlikely" to be subject to physical damage. If you can convince the inspector it's not subject to physical damage, per NEC it can be exposed if it does not violate other parts of the code. However, some local codes may be more specific about this.

My AHJ let me run NMB in conduit for the garage portion of the run (not inside the house) for this reason of "protection". It was a good 25ft.

 

[Supratachophobia]

If you are putting in a sub panel, you might as well run something much bigger than 6

Not if the stab rating of his panel won't allow it. But nothing in the code keeping you from having total breakers exceed the OCPD of the run. Essentially that's what your main panel is doing. OP just needs to be aware that while he can run the butter-churner and the EV charger at the same time, he shouldn't.

 

[NY_Rob]

Ehhh, I think there's a provision to round up or we are missing something. If not, every Tesla HPWC in the last 10 years would be in code violation.

The Tesla HPWC has quite a few max amperage settings, 40 amps is one of them.

 

[SANZC02]

Ehhh, I think there's a provision to round up or we are missing something. If not, every Tesla HPWC in the last 10 years would be in code violation.

Some codes allow to round up as a 55 amp breaker is rare.

Personally I’m not a fan of rounding up as at some point the person installing that circuit will not be around and all people will see is the 60 amp breaker and thing that circuit is good for 48 amp continuous load. I’d prefer the 50 amp breaker so the lowest portion of that circuit is visible and not hidden in a wall.

 

[ElGuano]

+1. Rounding up to the next available size breaker should be allowed (I think a snippet from the code was posted above), but my personal risk appetite is closer to SANZC02, and if charging at 40a anyway, a 60a breaker isn't going to make a difference in the first place. I'm happy for it to trip if it hits 50.

 

[Supratachophobia]

The Tesla HPWC has quite a few max amperage settings, 40 amps is one of them.

Mine go up to 80......

Sponsored