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NEMA 14-50 is dead - all hail NEMA 6-50
- Thread starter eprosenx
- Start date
I went with the 14-50 because I also wanted a 120V outlet near the garage door for my pressure washer and electric hedge-trimmer during the summer and the electric start on my snow thrower during the winter. I bought a two-outlet box on Amazon that has both the 14-50 and a standard 120V plug. If you need the neutral anyway, might as well use the 14-50.
TheRFMan
Member
Electrical code required a 14-50 to be on a dedicated circuit. You should not be connecting a 5-15 or 5-20 to the came circuit. as the 14-50.
You can however get an adapter that connects into a 14-50 and will give you 120V outlets. Those are commonly used by people replacing electric ranges with gas one.
I’ll look into that, though it was installed by a licensed electrician who I know is conversant with electrical code. Also, it is a pre-fabricated unit with separate breakers and the two sockets built in that is sold at electric supply outlets everywhere. Perhaps this restriction is a local electrical code in your state or county, rather then NEC?
Yep. Super common here as well. Every campground has hundreds of them. A single pedestal with 50 30 and 15 outlets. All connected to one 50 amp breaker at the main panel.
Looks like that’s correct. I’m reading that the 2017 NEC update clarified that EV charging circuits must be dedicated circuits, even if a receptacle is used. So I’ll just call mine officially not an EV charging circuit - I’ll call it a single branch circuit with multiple sockets. I have a Tesla Wall Connector on the opposite wall of the garage on its own circuit that can reach both cars if it came to an inspection, though we don’t have those where I live (semi-rural with no Use & Occupancy certificates or inspections).
Ugh. @TheRFMan left out a vitally important piece of what part of NEC he was referring to. It's in the section 625 that is specifically about electric vehicle charging!
That does state that any circuit being installed for electric vehicle charging must be a dedicated circuit with only a single outlet.
What @AmokTime and @Webeevdrivers are talking about is true for other general kinds of things, like RV outlets, etc. etc. That is for other situations that are not circuits for EV charging.
Although, I think it's generally kind of stupid to have different kinds of requirements in code depending on what the "intention" or "purpose" of a circuit is going to be. That's really hokey and fuzzy.
It’s very hokey. EV charging circuit vs. RV plug. Same circuit, same socket, different rules. NEC nails most things down pretty tightly.
TheRFMan
Member
Good point. The context here is EV charging, but I should have been more clear.
Regardless, I think it’s better practice to have any outlet 30A or higher on a dedicated circuit. (My opinion as an electrical engineer, not code-related).
What you have is actually a “sub panel” which then has a 50a 240v circuit and a 20a 120v circuit in it.
Nothing to see here. Totally legit. No issues (one might argue a load calculation issue if it is only fed with 50a in total, but the argument would be that they are never used at the same time$.
Also, I absolutely agree that having different code for different use cases of an RV vs an EV is pretty ridiculous. The circuit is identical but yet the code requirements for EV’s are very different. It really frustrates me. I would love to flush the existing NEC code down the drain and write a simplified version. The NEC is very solid, but it has an incredible amount of convoluted cruft in it.
TheRFMan
Member
I’m not trying to be pedantic, but when it comes to electrical safety, liberal interpretations can lead to bad outcomes.
A junction box is not a sub-panel. A sub-panel, with breakers for the incoming circuit as well as one each for the 14-50 outlet and the 5-20 outlet, would be ideal in this case.
What was described is a junction box with an incoming wire feeding both outlets all connected to the same breaker in the panel. It’s that junction that can be dangerous. How is the 12 gauge wire for the 120v outlet joined to the 6 gauge wire for the 240v? Were both conductors jammed in the 14-50 outlet terminals? Could that cause a weaker or looser connection leading to heating up of the outlet? Probably not, but there is a chance.
I agree in general, though this junction box is a commercially-manufactured and fairly popular product, not something the electrician cobbled together. The fact that this is apparently permitted for use as an RV plug, but not for an EV plug suggests they added a level of rigor because the current will be continuous on an EV plug, where it mightn’t be for an RV. Still weird to have different rules based on intended use. That suggests to me that the RV use case is only conditionally safe, not as rigorously safe as the EV rule requires.
I think some of you are all missing a key point about the combination pedestal used at RV parks versus the OP's installation situation. The 50 amp wires are considered a FEEDER to the pedestal at the RV park, not a branch circuit, so the rules are slightly different. The FEEDER is then tapped at the pedestal per 240.21 (tap rule) with tap conductors wired to circuit breakers to acheive the separate 240 volt and 120 volt BRANCH CIRCUITS. If I understand the OP installation, he has a 120 volt outlet tapped from the 50 amp branch circuit without any overcurrent protection, which is not NEC compliant.
Is everyone here talking about the same thing? The item below is the RV panel I think people are talking about. The only open question in my mind is the size of the upstream breaker feeding this. You might be able to get away with a 50A breaker and feed line, but probably 80A is more appropriate. The breaker bus inside is rated for 100A, so you could replace the NEMA 5-20 duplex outlet and breaker with a NEMA 6-20 outlet and double pole breaker. I don't see any reason why you couldn't use this for EV charging because it has breakers for each dedicated outlet.
GE RV Panel with 50 Amp and 30 AMP RV Receptacles and a 20 Amp GFCI Receptacle-GE1LU532SS - The Home Depot
GE RV Panel with 50 Amp and 30 AMP RV Receptacles and a 20 Amp GFCI Receptacle-GE1LU532SS - The Home Depot
Sub panels do not require incoming breakers, just a breaker in the main. eprosenx is correct that this is a sub panel or "load center" since it includes separate breakers for the 110V/220V circuits, presumably fed by a proper bus bar. I'll disagree with him however on the EV/RV distinction since the NEC is clear regarding continuous use circuits. This arrangement would not be legal as a "EV Charging Station" nor would it be safe as a charging station for 2 cars at once (220V and 110V), but it's fine as a RV station and fine for nearly any reasonable use case.
Interesting thread since I have somewhat of a dilemma I posted about in a separate thread. I have a 6-50 in my garage going to a 70a breaker in the main panel which is behind the wall of the outlet. It is currently labeled “welder” which I don’t have (recently moved into this house). I have an appointment for electrician to install 14-50 or they said they can keep the 6-50 but regardless will need a new breaker of 50a. I have zero electricity knowledge but I’m still confused as to why I can’t just use the current 6-50 with the 70a given the Tesla 3 max at 32 based on what I read. I am still waiting for the car to deliver so didn’t try to plug it yet. I guess to be safe I can just invest the additional $400 for a new breaker and outlet?
pdx_m3s
Active Member
Do you know what gauge wire is used? I believe your supposed to match the breaker with the outlet rating. And most importantly, you don't want your breaker rated at higher amps than the wire... as that defeats the purpose of a breaker.
Regardless, I would just use the existing plug and swap in a 50-amp breaker. No need to upgrade to 14-50, which could be expensive, as 14-50 requires an extra conductor, and your 6-50 outlet may not have that extra conductor wired into the outlet box..
nwdiver
Well-Known Member
That's what I use. I'm surprised this isn't more common. You run one line and you get a NEMA 14-50, a HPWC AND a regular 120v outlet for vacuuming or whatever.
In my case, the circuit to the RV box has a 50-amp breaker in the panel. The box itself has a 50-amp breaker on the 14-50 and a 15-amp breaker on the 120V plug, so there is over current protection.
It's possible that some defect in your charger or outlet could overload the wiring or outlet and start a fire before the 70A breaker intervenes.
Of course you could still have a defective charger catch fire on a 50A breaker, but there's nothing the building codes can do about that. NEC can only ensure safety for your home wiring, it's up to UL to ensure safety for the devices you plug in. And of course a spontaneous attic wiring junction fire is much worse than a charger melting on the floor of your garage.
Your 6-50 outlet is fine, it's just not legal or safe to have it so loosely protected. A 50A breaker costs $12 and takes 7 minutes to install, but can easily be done in less than 1 minute, maybe get more quotes.
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