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Future-proof NEMA 14-50 install

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Romex cannot be run in a conduit. There is too much thermal insulation and the wire will get hotter and may exceed its rating. If there is a fire, don’t expect the insurance company to cover. Romex is to be used INSIDE walls without conduit. I used AWG4 XHHN-2 inside 1” EMT. You can also use flexible conduit if that is easier. Make sure you have a permit for the work before you start.
This information is incorrect.
ARTICLE 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS
II. Installation
334.15 Exposed Work. In exposed work, except as provided in 300.11(A), cable shall be installed as specified in 334.15(A) through (C).

(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix -XW, or other approved means extending at least 150 mm (6 in.) above the floor. [ROP 7-94] Type NMC cable installed in shallow chases or grooves in masonry, concrete, or adobe shall be protected in accordance with the requirements in 300.4(F) and covered with plaster, adobe, or similar finish.
 
Romex cannot be run in a conduit. There is too much thermal insulation and the wire will get hotter and may exceed its rating. If there is a fire, don’t expect the insurance company to cover. Romex is to be used INSIDE walls without conduit. I used AWG4 XHHN-2 inside 1” EMT. You can also use flexible conduit if that is easier. Make sure you have a permit for the work before you start.

This is quite simply incorrect.

It is a very common misconception (and I used to believe the same), but upon reading the actual NFPA 70 (2017 NEC) docs I can not find anywhere thar phrohibits this and in fact it requires some sections to be in conduit for protection.

If you believe this to be in error, please post the code section references. 2017 NEC is available for free on the NFPA web site (registration required).
 
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I'm glomming onto this thread for one specific clarification: I'm having an electrician install a 14-50 outlet tomorrow to use with the Universal Connector. I may want to upgrade to the Wall Charger at some point, but I'm pretty the Universal will work fine for me. To save money, I'm going to buy the wire and do the manual labor of crawling under the house and running it from panel to outlet. What exact wire should I buy to use with the Universal Connector - and possibly later with the Wall Charger? Thanks.
 
I plan on using the supplied mobile connector and will install a 14-50 sometime in the next week. I've been going back and forth on "future-proofing" or not. My scenario is pretty basic so I need to decide if it's worth it to just run a new line if/when I have the need while still at this house. A big IF

I will be running ~30' of wire from my main panel through an unfinished room in my basement directly to the garage wall. I have the 50 Amp breaker (verified room in the panel for it) a NEMA 14-50 plug, a wall plate, and outlet box so all that's left is the wire. To avoid buying a 50' roll of 6/3 ROMEX I went to a local electrical shop today and priced out 35" of 6/3 ($2.50/foot). Then I asked about 4/3 and that comes in $5.50/foot. So I spend $90ish now on wire OR double that to go 4/3. I'm leaning 6/3 now

The spot on the wall is in question (and needs to be determined before buying wire tomorrow morning). I'd like to place it so that I can charge when backed into the garage or backed into the driveway. After looking at it last night I think the optimal spot would be somewhere towards the front of the car (when backed into garage) right around where the door hinge sits. That should give me plenty of room for both charging locations while avoiding hitting my door with it when I get in/out every day. I think that sweet spot is roughly 4' from nose?

Any thoughts on my plug location would be welcomed!
 
I'm glomming onto this thread for one specific clarification: I'm having an electrician install a 14-50 outlet tomorrow to use with the Universal Connector. I may want to upgrade to the Wall Charger at some point, but I'm pretty the Universal will work fine for me. To save money, I'm going to buy the wire and do the manual labor of crawling under the house and running it from panel to outlet. What exact wire should I buy to use with the Universal Connector - and possibly later with the Wall Charger? Thanks.

If you can use Romex in your area (aka Type NM-B cable), and you want a 50 amp breaker for your 14-50, buy 6/3 Romex.
If you want the Wall Connector to be set to use a 50 amp breaker, stick with the above.

If you want the Wall Connector to have a 60 amp breaker, which will let the M3 charge at its max 48 amps, you'll need 4/3 Romex and a 60 amp breaker. But while the 14-50 outlet is in place, you are required to use no more than a 50 amp breaker. So if you think you'd want 48 amp charging with the Wall Connector, buy 4/3 Romex and use it with your 14-50 outlet and 50 amp breaker. Then, when you get the Wall Connector, swap out the breaker for a 60 amp breaker and wire the Wall Connector in place of the 14-50 outlet.
 
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If you can use Romex in your area (aka Type NM-B cable), and you want a 50 amp breaker for your 14-50, buy 6/3 Romex.
If you want the Wall Connector to be set to use a 50 amp breaker, stick with the above.

If you want the Wall Connector to have a 60 amp breaker, which will let the M3 charge at its max 48 amps, you'll need 4/3 Romex and a 60 amp breaker. But while the 14-50 outlet is in place, you are required to use no more than a 50 amp breaker. So if you think you'd want 48 amp charging with the Wall Connector, buy 4/3 Romex and use it with your 14-50 outlet and 50 amp breaker. Then, when you get the Wall Connector, swap out the breaker for a 60 amp breaker and wire the Wall Connector in place of the 14-50 outlet.

Totally agree.

To the OP: Make sure to get an electrical box of the right size to fit a 14-50. 6 AWG is pretty stiff and 4 AWG is even more so. I am not sure the box fill requirements, but I am pretty sure the 14-50's are always intended to go in a double gang box (note their screw hole pattern is setup for this - it spans two positions in the box).

You also want a box that has good structural stability (not just like holding on to the sheetrock) since the insertion and removal force on a 14-50 is pretty high.

Make sure also to run the wire properly through the wall/ceiling according to code in the unfinished room. Conductors of a certain size I think can be run across floor joists in unfinished basements, but smaller wires need to go through the joists (and of course if you plan to finish something later you don't want anything running across the joists).
 
While on the subject of Romex:
My situation for 14-50 outlet install is two 6AWG runs inside the garage (everything is inside) to two 14-50 outlets I installed...currently both circuits are on 20A breakers for extra safety, but now that I have my car, I'll change the breaker.

For this 14-50 install (which I did a couple years ago), I ended up running 6AWG Romex from my panel to the two outlets. (If I had known more I would have run THHN or whatever through appropriate size conduit I think, since it would have got me a 48A (60A breaker) capable run, but doesn't really matter, 40A is fine). Whenever the Romex is below 8' from the floor, it is behind nail guards when going through studs, and behind plywood sheathing and secured to the studs with Romex staples.
However, in my garage, ceiling is unfinished, so above 8' I ended up just routing it (and securing it with appropriate Romex staples) along the edge of the ceiling (right against the roof/wall connection) above the joists and trusses (and then come back down behind the plywood which is the wall surface below 8'). So above 8', the Romex is exposed, not in conduit. It's also not vulnerable to any damage there. It does briefly go through a small section of conduit to get around a massive 16x4 (or something) beam which forms the top of the garage openings, below about 8', which I didn't want to drill through, then goes behind the plywood at lower elevation to get to the junction boxes.

My impression was at the time that this was to code, from the reading I did. But wondering if anyone can confirm - does this sound code compliant? Not really too concerned as there is no electrical danger, but wondering about code compliance with the exposed Romex. I know the brief run of Romex in conduit is ok, since the conduit is appropriate size, and it is indoors.

Another side question: Am I correct in understanding that some local codes don't allow two 50A circuits in a quad breaker like this? https://www.amazon.com/Eaton-BQ2502...pID=41KRgxa8nHL&preST=_SX342_QL70_&dpSrc=srch

I don't have to have two 50A circuits right now (I'll go to 50A/20A), but I assumed that since they sell these 50A/50A it would be to code (assuming panel load calculations, etc., are ok) But maybe not?
 
I think what is normally done in these situations is to run romex to a junction box where you connect the conduit to. Then you run THHN wire in the conduit, and romex in the exposed basement, and wire nut the runs together in the junction box.

Honestly, I would go ahead and just install the Wall Connector now. It is a more robust charging set up.

But yes, you can still install a 50A breaker if you use heavier gauge wire. I think the 4 gauge should still fit in the receptacle and breaker lugs.
I'm not sure it's that simple, THHN and romex can have different heat ratings, not sure how important this is to code but you wouldn't want to exceed the lower of the two ratings.. I had my electrician run 4awg THHN all the way to the panel on the far side of the house. The downside to this is that you have to pay upfront of an extra wire.

After going a day without power then not being able to charge fully the next day with the limited 6 hours, I'm considering trying to get a wall connector, but I'll probably hold off for a while.

My initial thought was that my wife might get a tesla and then the wall connectors would make sense, but I don't think I'll be buying another tesla now.
 
This is a great thread. I have learned a lot. In 2 days I'm having an electrician come out to install a NEMA 14-50. I have a new Model 3 Performance and am ready to get level 2 charging in my garage. The 120V outlet isn't cutting it. I want to have the electrician install wiring that can support a wall connector, if I decide to do that later. I'm sure I could do the work to switch from a NEMA 14-50 outlet a wall connector myself. I cannot fish wire from my basement to my garage myself. So, I have decided to have 4 AWG wire installed. All this future-proofing got me to thinking about what happens in a few years when my wife wants a new car. We may get another Tesla, or some other EV. Then we will need a way to charge 2 cars. Then I saw that you can purchase a NEMA 14-50 Y splitter online for less than $100. Why couldn't we just both plug into that, assuming we kept each car charging at 20 amps. That would be a 40 amp load which is the max the 50 amp breaker should support. I'm usually home at least 10 hours at a time, so 200 miles of charging per day would easily keep my car topped off. I want to ask a few questions which I know the electrician will answer for me, but the collective experience of the forum would be informative.

1. Is that in any way dangerous to use a Y splitter? Anyone else done it? I don't think an electrician would ever run 2 NEMA 14-50 outlets to one 50 amp breaker, so I am kind of doing a work around with the Y splitter that is doing the same thing.
2. At one time I was thinking of installing a 60 amp breaker to the NEMA 14-50. It is tempting because if there was a 60 amp breaker, then each car could safely draw 25 amps each which is getting pretty close to the maximum 32 amps. Is that safe for the NEMA 14-50 to truly have exactly 50 amps going through it? It is rated for 50 amps so I would think it should be.

I have decided for now that it probably is a bad idea to put anything other than a 50 amp breaker on a NEMA 14-50, so my other option in the future is to stagger charging time for the 2 cars at 32 amps each, however, I think this would probably be a PITA since there would be irregularities in our usage - just asking for a tripped breaker. I would just charge each car at 20 amps regularly, and if for some reason one car is really low, could always unplug the fuller car and charge the other at 32 amps.
 
Option 1: In two years, get a pair of WCs that can safely load share off your circuit. At that time, replace the 50 amp breaker with an 80 amp one (to match the 4 gauge wire) and the two WCs can then share 80 amps.

That’s assuming your second EV is a Tesla, which isn’t a given in 2 years. I mean, if you’re future proofing, you might as well do it right.

The Y splitter is a kludge and is subject to “Oops! I forgot about that!”.

Option 2: Why not run two 40 amp circuits. You’d be using 8 gauge wiring, and running the Mobile Connector at its max. of 32A. Then you’d be set for a second EV on its own circuit regardless of what kind of EV it is.
 
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Thanks for the input! You are definitely right about the kludge factor. I am bringing up the Y connector for my curiosity of safety, and curious if others have used one. I'm not sure I would use one as a long term solution out of my gut instinct, but I wanted to apply more logic than gut instinct. Obviously, I am trying to save money, or I would just install a wall connector today. The Y splitter I admit does not "Look" great hanging off the wall, and a wall connector looks really cool. I would like to take aesthetics out consideration. Logically, assuming the Y connector works as it is designed, there should be no safety risk to using such a device to charge cars, as long as you always kept the cars charging at 20 amps. If for some reason the load on the circuit exceeded 50 amps, the 50 amp breaker would trip. This is exactly what happens in homes all the time when somebody plugs in a vacuum cleaner in the same circuit as toaster. The breaker does it's job and trips. People use these Y splitters all the time on their RVs and it seems acceptable in that application.

I am going to ask the electrician also about a subpanel in the garage. I suspect it will be a lot more money, but would be most future-proof if have 100 amp service to a garage subpanel. Kind of sucks, my wife and I had our house custom built 5 years ago, and neither myself nor the builder thought of the need for high voltage in the garage at the time. Should have had a subpanel put in then.
 
Never rely on the breaker tripping. It is very much a last resort kind of thing. And they don’t trip immediately on a 50% or whatever overload. They only trip immediately on a dead short circuit (if they are working properly). 10kW is an amazing amount of power. I mean, a regular 120V, 15A circuit can weld wires together on a short. Imagine what 60A/240V can do (8x more power).

So, yes, a 100 amp or whatever sub panel would be the most future proof. Two 8 gauge 40A circuits would also work.
 
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Never rely on the breaker tripping. It is very much a last resort kind of thing. And they don’t trip immediately on a 50% or whatever overload. They only trip immediately on a dead short circuit (if they are working properly). 10kW is an amazing amount of power. I mean, a regular 120V, 15A circuit can weld wires together on a short. Imagine what 60A/240V can do (8x more power).

So, yes, a 100 amp or whatever sub panel would be the most future proof. Two 8 gauge 40A circuits would also work.

Also, there’s no need anymore to install a NEMA 14-50. You could save some wiring costs and install a NEMA 6-50. The 6-50 requires one less wire, so it should actually be cheaper even including the $35 cost of the 6-50 adapter.
 
If you have 4 gauge wire and the capacity to increase the breaker in your main panel to 80 amps, you could install a sub-panel and put two 40 amp breakers in the sub-panel wired to two 14-50 outlets. The Tesla Mobile Connector only pulls 32 amps, so this is safe and code compliant. Of course, using two Tesla Wall Connectors is a better solution, regardless of the amperage (40 or 80 amps) and is compatible with other EVs provided you either change the connector to J1772 or use a Tesla to J1772 adapter.
 
I don't know if Atoms is right or not, but I can't imagine an electrician willing to pull romex in conduit- just because it would be so difficult.
Running thhn without conduit will look crummy and will make the little critters wish you hadn't.
 
If you have 4 gauge wire and the capacity to increase the breaker in your main panel to 80 amps, you could install a sub-panel and put two 40 amp breakers in the sub-panel wired to two 14-50 outlets. The Tesla Mobile Connector only pulls 32 amps, so this is safe and code compliant. Of course, using two Tesla Wall Connectors is a better solution, regardless of the amperage (40 or 80 amps) and is compatible with other EVs provided you either change the connector to J1772 or use a Tesla to J1772 adapter.

I would just note that I will just about never recommend running wire only sufficient for 40amps to a new 50a receptacle. Who knows what you might want to do in the future. Generally 40 amp circuits on 50amp receptacles are considered bad practice (though fully code compliant if your intended load is only 32a continuous).

So I think if you did this subpanel route you could actually do two 50a circuits since your intended load is only 32a each, I think the load calculations would be the same. But if you are uncomfortable with that you could wire them for 50a but still breaker them at 40a. (Easy to change breakers down the road if needs change)
 
Not critically important but just thought I should update on my decision. May help someone. I had the electrician come out and he said that 4 AWG wire would be "a lot of money" and encouraged me to do 6 AWG wire. He wanted to install MC cable as it would require less labor cost compared to bending conduit etc. He measured about a 75 foot run and quoted me $1900 to put in a wall connector. That price doe NOT include the actual wall connector. He told me that if he would put in a 14-50 outlet it would need to be GFCI and would cost $400-$500 for just the outlet so it would make more sense to just put in the wall connector. This sounds like bull$#!& to me but I'm not certain. He was convincing. Supposedly, he put in a regular 14-50 outlet in a garage previously and it did not pass inspection. I was shocked at the price and decided to not place myself over a barrel and instead decided to do this job myself. I have a scientific background and understand electricity so it was simple to do a small amount of research online and order the supplies and do it myself. I did sacrifice my time and spent about one full Saturday installing, cleaning up etc. I actually enjoy this stuff, so it made sense for me, but if someone else is a highly paid and not interested in a project, then just let the electrician perform a wallet-ectomy and move on. So, as I said the electrician quoted $1900 for the wire and breaker and I was supposed to provide my own wall connector ($500). With the wall connector it would have cost me a total of $2400. Instead I upgraded to 4/3 MC cable and did the project for $312.50 for everything including permit except the wall connector. With Wall connector total is $812.50. I measured correctly and it was actually 50 foot run NOT 75 feet. Oh yeah, I had to pay the electrician $59 to come out and give me the quote also.

Breakdown of my DIY wall connector install:
-Tesla Wall Connector $500
-50' MC 4/3 cable $179+$26 shipping= $204.50 @Wesbell
-CH 80 Amp 2-pole circuit breaker @ Pacific Coast Breaker $45.00.
- Hubbel-Raco 3304DB double bite saddle connectors 1 in. Got 5 for $20.00 @Amazon (highly recommend not cheaping out on on these - the saddle connectors are super solid and not going to slip)
- Cable straps 1 hole $7 (Home depot)
Acoustic sealant - to seal the repair to the vapor barrier
Great stuff foam - to help repair insulation and fill holes
Permit and inspection $36.

So now I am Happy Camping with a Wall Connector set to 64 Amps and is certainly future proofed for any other Tesla I buy. It charges my car super fast and is just fantastic to have zero anxiety about charging. I am glad I didn't give all my hard earned cash to the electrician and end up with some jerry rigged set up just to save some money.

One thing I want to complain about is what an absolute bear it was to get 4 gauge wire into the wall connector. Hand to God, I spent about one freaking hour just trying to get the wires into the 240V wire terminals. It is so stupidly narrow. The wire has to be perfectly round. I even removed one wire in each connector to get it to fit (4 gauge wire is about 8 individual wires bundled together). Stupid design. To compare, the breaker terminal was incredibly easy to get the wire connected. The breaker has a capacious space to insert the wire. Took less than 2 minutes. Tesla really botched that design on the wall connector. I don't know how in the hell anybody will get 3 AWG wire in there.
 
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Not critically important but just thought I should update on my decision. May help someone. I had the electrician come out and he said that 4 AWG wire would be "a lot of money" and encouraged me to do 6 AWG wire. He wanted to install MC cable as it would require less labor cost compared to bending conduit etc. He measured about a 75 foot run and quoted me $1900 to put in a wall connector. That price doe NOT include the actual wall connector. He told me that if he would put in a 14-50 outlet it would need to be GFCI and would cost $400-$500 for just the outlet so it would make more sense to just put in the wall connector. This sounds like bull$#!& to me but I'm not certain. He was convincing. Supposedly, he put in a regular 14-50 outlet in a garage previously and it did not pass inspection. I was shocked at the price and decided to not place myself over a barrel and instead decided to do this job myself. I have a scientific background and understand electricity so it was simple to do a small amount of research online and order the supplies and do it myself. I did sacrifice my time and spent about one full Saturday installing, cleaning up etc. I actually enjoy this stuff, so it made sense for me, but if someone else is a highly paid and not interested in a project, then just let the electrician perform a wallet-ectomy and move on. So, as I said the electrician quoted $1900 for the wire and breaker and I was supposed to provide my own wall connector ($500). With the wall connector it would have cost me a total of $2400. Instead I upgraded to 4/3 MC cable and did the project for $312.50 for everything including permit except the wall connector. With Wall connector total is $812.50. I measured correctly and it was actually 50 foot run NOT 75 feet. Oh yeah, I had to pay the electrician $59 to come out and give me the quote also.

Breakdown of my DIY wall connector install:
-Tesla Wall Connector $500
-50' MC 4/3 cable $179+$26 shipping= $204.50 @Wesbell
-CH 80 Amp 2-pole circuit breaker @ Pacific Coast Breaker $45.00.
- Hubbel-Raco 3304DB double bite saddle connectors 1 in. Got 5 for $20.00 @Amazon (highly recommend not cheaping out on on these - the saddle connectors are super solid and not going to slip)
- Cable straps 1 hole $7 (Home depot)
Acoustic sealant - to seal the repair to the vapor barrier
Great stuff foam - to help repair insulation and fill holes
Permit and inspection $36.

So now I am Happy Camping with a Wall Connector set to 64 Amps and is certainly future proofed for any other Tesla I buy. It charges my car super fast and is just fantastic to have zero anxiety about charging. I am glad I didn't give all my hard earned cash to the electrician and end up with some jerry rigged set up just to save some money.

One thing I want to complain about is what an absolute bear it was to get 4 gauge wire into the wall connector. Hand to God, I spent about one freaking hour just trying to get the wires into the 240V wire terminals. It is so stupidly narrow. The wire has to be perfectly round. I even removed one wire in each connector to get it to fit (4 gauge wire is about 8 individual wires bundled together). Stupid design. To compare, the breaker terminal was incredibly easy to get the wire connected. The breaker has a capacious space to insert the wire. Took less than 2 minutes. Tesla really botched that design on the wall connector. I don't know how in the hell anybody will get 3 AWG wire in there.

Nice! Thanks so much for posting this detailed followup!

Yeah, obviously those quoted prices were excessive. MC was a good idea to make it easier. Not as pretty looking, but extremely practical.

Charging for quotes is crazy. I don't know anyone around here that does that.

The electrician is correct that 2017 code now requires a GFCI breaker for EV charging receptacles. They are about $100 more than a regular non GFCI 50a breaker (maybe slightly more depending on brand). This is one reason I recommend the Wall Connector a lot over a 14-50. The GFCI cost helps make the Wall Connector price more tenable.

Did you use the Wall Connector top entry bracket that spaces it out from the wall? It might have been easier to get the wires in. Or perhaps bottom entry is easier than rear entry as well? (I did mine as rear entry, but only 6 AWG)

Note that cutting one of those wires off the conductors reduces its capacity at the most critical point (the connector). That is where overheating and failure usually happens. So that wire is now maybe good for 10 amps less than it was before (rated for 85 before). Obviously not an issue at 48 amps of charging, but if you get a different car later that actually draws 64 then it could be an issue. Creating "latent" deficiencies like that is very concerning.

Note that on really large gauge wire electricians use tools like this to manhandle the wires.
Cable Bender, 12-Inch - 50400 | Klein Tools - For Professionals since 1857
 
I didn't use the adapter since the cable has a bottom entry. I understand why you think that trimming one wire isn't a good idea and I was considering the same question as I decided to do it. However, consider that these connections are just the wire being pinched beween 2 metal plates at the terminal. The surface area of wire contacting the plates likely does not change at all based on what I did. There is only a fraction of any wire in contact to the metal plates in any terminal.