While awaiting delivery of our new Model 3 Performance, we had an electrician install a 14-50 outlet. He ran approximately 25' of individual 8ga wire to a 40A breaker. I was expecting a 50A breaker. Should I have him swap it to the larger size, or should there not be an issue drawing 32A. I understand the 80% rule, but wanted to make sure I wouldn't need to reduce the charging draw to less than 32A.
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14-50 requirements
- Thread starter recreationman
- Start date
For Hubbell 14-50 outlets, the desired model number is 9450A, not any of the RR450 variants. Have not seen any Bryant 14-50 outlet besides the 9450FR.
Leviton also has different models of 14-50 outlets. The common 279-S00 is the lower quality one, while the new and less common 1450R is the higher quality one.
Look for full size brass contacts to the plug blades to tell the difference. Smaller contacts or those made of less conductive materials like steel are more likely to overheat.
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I spent right around $400ish for my mobile charger parts. Had I not need an actual 240v outlet (6-50P) for welding, I'd have gone the wall connector route.
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It CAN pull 48A, but it doesn't have to. That word should not be "will".
FTFY
It bothers me when people give this kind of misleading information to new folks here on the forum, where it is giving the false idea that using the wall connector means you can't use anything less than a 60A circuit. That isn't true. Tesla's wall connector is very nice in having such configurability to run on various circuit levels. So running one on a 40 or 50 amp circuit is still a decent idea if it's somehow difficult or expensive to go bigger (or if people are reusing an existing lower amp circuit).
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And my words were 'up to 48 amps'. Not '48 amps'. Not '48 amps on this wiring'. Just stating what a wall connector can do. Sheesh. I'm out of here
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MikeRTX
Member
FWIW, there's really no inherent problem with Leviton receptacles. The main issue with them comes about when a plug is inserted and removed frequently, since they are essentially designed for permanent plug-in, like you'd have with a washing machine or electric range/oven, etc. Frequent use wears the contact points more than with heavier-duty commercial receptacles, and can cause them to loosen and potentially overheat or arc.
The vast majority of the horror stories you hear about fires, melted plugs or breakers, etc., are because the owner either:
1. Uses the wrong (under-rated) hardware (receptacle, breaker, wire gauge, etc.), or
2. Does not know about or does not observe the over-Amp (80%) cautions, or
3. Uses more than one appliance on the circuit, causing overload, or
4. Has old, worn, under-rated, or faulty wiring or breakers to begin with.
Leviton receptacles are UL rated for their intended use. Under normal circumstances, your breaker alone should protect from overload, especially with GFCI or arc-fault protection, but that's not to be counted on. But if your EVSE is kept plugged in, you use the properly-rated receptacle and hardware, and you don't misuse it, your Leviton will serve its purpose just fine.
The vast majority of the horror stories you hear about fires, melted plugs or breakers, etc., are because the owner either:
1. Uses the wrong (under-rated) hardware (receptacle, breaker, wire gauge, etc.), or
2. Does not know about or does not observe the over-Amp (80%) cautions, or
3. Uses more than one appliance on the circuit, causing overload, or
4. Has old, worn, under-rated, or faulty wiring or breakers to begin with.
Leviton receptacles are UL rated for their intended use. Under normal circumstances, your breaker alone should protect from overload, especially with GFCI or arc-fault protection, but that's not to be counted on. But if your EVSE is kept plugged in, you use the properly-rated receptacle and hardware, and you don't misuse it, your Leviton will serve its purpose just fine.
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I don't know what's specifically in the modern UL testing procedure (pay walled), but it in the relevant 1998 version (https://file.yzimgs.com/175706/2013061320441778.pdf) most devices seem to be be exempt from heat cycling testing. If that's still the case today, that probably explains some of the issues we see. For a stove that will rarely see max current for more than a few minutes, it'll never be an issue. But EVs are probably the toughest loads you can put on these outlets and will go from max temp to room temp often.
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I had a Leviton 5374 for 6-50 (similar design to the common Leviton 279-00 for 14-50) that have overheating warnings from a Tesla Mobile Connector unless I set the car to take only 26A or less instead of the default 32A (that was only a problem in warmer weather).
As you can see from the image from 5374 , it has half size contacts to the plug blades that look like they are made of something other than brass. So conductivity is lower and resistance is higher for a new receptacle. The half size contacts also look like they could get bent out of position more easily when plugs are inserted or removed.
I would not recommend a Leviton 279-S00 for 14-50 or Leviton 5374 for 6-50, but a Leviton 1450R for 14-50 should be ok (the Leviton 1450R has full size brass contacts and pressure clamp wire connections). However, it is less common and appears to be more expensive than the Bryant 9450FR. It is also relatively new, so most Leviton 14-50 receptacles that are already installed are the 279-S00 model.
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I get it the caution, but I too wonder if we don't over-react a bit on the 14-50 receptable issue. An example: I have several 14-50's in my garage. Likely Levitons. They get used once or twice a year, and for no more than 32 amps. Am I going to pull them and replace them w/commerial receptables? Nope. Would I install them myself? Well, no. But....
Now if I was plugging in and out even a few times a month, well, I'd probably replace them. Pulling over 32A? Again probably. Doing both? Definitely. Plugged in once and left? Pulling 32A max? I ran that way for a few days (Wall Charger was on back order) and there was nothing even warm on the receptacle.
Let me also say I too have looked at a number of failure pics. To me each one looks like arcing was occurring at wire termination. Ain't no product gonna fix a shitty installation!
So use case, for me, decides what's needed, and installation care and quality are the secret sauce.
Mind you there is also a great case for "buy once, cry once" and get it done right the first time.
Now if I was plugging in and out even a few times a month, well, I'd probably replace them. Pulling over 32A? Again probably. Doing both? Definitely. Plugged in once and left? Pulling 32A max? I ran that way for a few days (Wall Charger was on back order) and there was nothing even warm on the receptacle.
Let me also say I too have looked at a number of failure pics. To me each one looks like arcing was occurring at wire termination. Ain't no product gonna fix a shitty installation!
So use case, for me, decides what's needed, and installation care and quality are the secret sauce.
Mind you there is also a great case for "buy once, cry once" and get it done right the first time.
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Some of the failure pictures show melting at the front of the outlet, with no damage on the back where the wire connections are. In such cases, careful installation did not / would not help.
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