You mention the Hubbell outlet but then linked to the Bryant outlet. Which way round did you mean?
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Master Thread: Definitive 14-50 NEMA Outlet Guide
- Thread starter gilscales
- Start date
You mention the Hubbell outlet but then linked to the Bryant outlet. Which way round did you mean?
mrau
Authorized Driver
Oops. I meant Bryant 14-50. Very similar to the Hubbell, but usually cost less. They both use the Hubbell cover plate.
DMC-Orangeville
Audi eTron & John Deere 5100E
You have touched on one of the really *sticky* issues (at least in Canada) on the 14-50 plug.
Up until late 2016 the Gen1 UMC came with a 40 amp rated 14-50 plug. There was a garage fire in Toronto that year and it was attributed to the charging Tesla's 14-50 connector getting too hot. Could have been the plug - could have been the receptacle....we'll never know. What did happen, at the end of 16/beginning of 17, Tesla started sending out new UMC, and new 14-50 adapter to ALL existing Canadian owners, all rated 32 amps. (We were supposed to return the old ones, and some people did
). All new Canadian Teslas were now equipped with the 32 amp connector. For a brief period, there was a bit of an uproar about smuggling the US adapter up to Canada, but eventually, the US models also were de-rated to 32 amps.So, as economics go, some of the new owners began to look at wiring up 14-50's on a 40 amp breaker (80% = 32 amps). Smaller wire, less expensive installation. This ticked off the Electrical Safety Authority (ESA). In their eyes, If a 50 amp (40 amp rated) receptacle is in play, what is to stop someone in an older Tesla, or others, from plugging in and drawing 40 amps. There are a couple of threads about this on this forum.
I was a supplier to the electrical industry (Including Receptacles - Midwest, and Aluminium/copper building wire - Alcan, Nexans), so I wrote an email to one of the chief inspectors at ESA for his opinion. He wrote a long answer - someone may be able to find it here -but in essence, he said 'If it's rated at 50 amps, you'd better use 50 amp rated cable, and a 50 amp breaker".
This comment was generally ignored, and eventually, ESA softened their position. That's why he wrote it on your receptacle, and it's a good idea. This is why we should always draw a permit, and get the job inspected
Canada folks. Other Countries/States YMMV.
PS I won't comment on the aluminium/copper wire discussion, above, it's a 5 page story. Also, Midwest does make a great metal heavy duty outdoor receptacle U054. The actual receptacle was Cooper, but may have changed in the last few years.
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Black306
Active Member
Yeah, it's interesting that Tesla's Wall Connector went from 80A down to 48A and their 14-50 Mobile Connector went from 40A down to 32A. Part of that may be that overnight is overnight, so people would prefer to have a longer/thinner cord and cheaper system. But there's surely an aspect to it that is the result of electrical codes/products not being ready for steady-state use at 80% of max rated current. Especially in the middle of the night, and especially in the garage.
JCtx
Member
Okay gang. Thanks a million for the super helpful info. I'm going to go with 50A 41--50 outlet, even if it's Romex. The electrician that will do the work, actually did my house himself (that's why I called him), so I won't get a permit. I thought he'd be more expensive, but the construction VP of the company referred me to him, so he might be giving me a break with the price. If he vouches for a Leviton, I'd accept it... but will scrutinize closely if it gets hot while charging or not. I will leave the plug connected unless going on a trip, which might happen a few times a year. Will keep you posted guys, and thanks again for all the help; greatly appreciated.
I'll second this. Just buy the Bryant and let your electrician know he doesn't need one. Whether he knocks $10 off the install cost doesn't really matter, your house won't burn down while you are sleeping.
Sure, the "not Leviton" ones are better, but really, this is less of an issue now that people have the newer 2nd gen UMC, which helps this in two ways:
1. Only pulling 32A instead of 40 from a 50A rated circuit/outlet. It's less stress and heat. I didn't know what I had until I started seeing threads on here and checked, and yes, I do have a Leviton and haven't gotten around to installing the wall connector that is still sitting in the box in my garage. But I run my car at 31A instead of 40 to keep the heat down.
2. The 2nd gen UMC does have a temperature sensor in the plug. So this is an extra layer of safety that the 1st gen UMC didn't have. And if that temperature sensor flags, the car will stop charging.
1. Only pulling 32A instead of 40 from a 50A rated circuit/outlet. It's less stress and heat. I didn't know what I had until I started seeing threads on here and checked, and yes, I do have a Leviton and haven't gotten around to installing the wall connector that is still sitting in the box in my garage. But I run my car at 31A instead of 40 to keep the heat down.
2. The 2nd gen UMC does have a temperature sensor in the plug. So this is an extra layer of safety that the 1st gen UMC didn't have. And if that temperature sensor flags, the car will stop charging.
JCtx
Member
That's good to hear. And with 32A on a 50A circuit, and the cables properly clamped down, I don't see any issues even with a Leviton. I'd only upgrade it if I feel the cable or anything around feeling hot. Otherwise, there's no need IMO with a max of 32A. If I was going to pull 40A, then I'd probably upgrade just in case.
Watts_Up
Well-Known Member
Also it depend how often someone is going to plug and unplug a socket.
Typically a portable charger will be unplugged may be once a year for taking a summer trip vacation.
If someone need to unplug every weekend to go to a cabin, it would be safer then to get a second charger.
JCtx
Member
Thanks. I'm on the first group, so maybe unplug it a few times a year at the most... and only if there are still 14-50 outlets available that we might need in an emergency. If not, then it'd stay permanently connected, and just take the 120V adapter.
Question - if I have a properly installed 70A breaker with 6-50 outlet, do I risk anything such as damaging the battery? I’m not an electrician but my understanding is that the charge is capped at 32A so I should be ok? I may have oversimplified a complex issue but please help
Seems like the breaker is not appropriate for the outlet. I’m sure someone will chime in otherwise.
In any case if you have a Model 3 with official Tesla charging equipment it should automatically cap at 32A. If for some reason you notice it doesn’t you can manually reduce to any lower limit you prefer in the charging screen in the car.
Personally I have no need to rapid charge so I have mine capped at 9A actually. But that’s just me. I’m sure few if any others do that slow.
In any case if you have a Model 3 with official Tesla charging equipment it should automatically cap at 32A. If for some reason you notice it doesn’t you can manually reduce to any lower limit you prefer in the charging screen in the car.
Personally I have no need to rapid charge so I have mine capped at 9A actually. But that’s just me. I’m sure few if any others do that slow.
davewill
Active Member
No, just using the circuit won't cause any problems with the car. However, since there's no such thing as a "properly installed" 70a breaker with a 6-50, it's hard to say any real certainty that nothing at all will happen. You certainly shouldn't leave it that way. If any sort of short circuit were to occur, the outlet and maybe the wiring could burn up before the breaker blew.
Taken to the extreme and by that logic, you shouldn't even put a breaker between the telephone pole and the 6-50. The breaker is at least in part to protect the wiring(and by extension, the house) from unexpected conditions. In this case, here are a few obvious conditions:
- There's a defect in the UMC or the Tesla that gets it more than 32 amps continuously. This is very unlikely, but must be considered.
- Someone plugs in a welder or whatever, after you move out.
- Something shorts the wire, whether its a screw being placed through it, or a nice sharp ax falling on it(its in a garage, and >should< be in conduit if it were put in today, but whatever).
In Canada,. I'm sure the code is 80% of the breaker rating, just to be safe. Unless your connecting the Tesla charger, I would downsize the breaker. The M3 can only take 32 Amps yet your powering it with a 70amp breaker. I hope you have the right gauge of wire for this breaker.
At 80%, you have 56Amp of energy flowing to your charger you can use.
Gauss Guzzler
Safety Score = 42
I'm surprised how often this comes up. No. You must not use a 70A breaker with a 50A outlet. Nor should you use a 70A breaker with 6 AWG wire.
It's possible that you have larger 4 AWG wiring which would be nice, but it still doesn't solve the problem with the outlet. The *only* purpose of the circuit breaker is to protect the outlet and household wiring from catching fire if overloaded -- it is not intended to protect your car, charger, or you.
Your car is at no risk from this setup but your house is at risk of fire if something were to go wrong along the way. Have an electrician replace the breaker with a 50A version.
Its the same in the US, but it isn't necessarily to be 'safe', its to be 'reliable'. The expectation with continuous loads(>3 hours) like EVs is that the wires and breaker will warm up and cause the breaker to trip.
At least in the US, everything needs to be downrated that 80%, so for the 32 amp UMC, you need a 40 amp breaker and wires capable(before derating the 80%) of 40 amps, and an outlet like 14-50 or 6-50. If I were running it myself(new), I'd just wire the 14-50 for 50 amp service.
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