After using a NEMA 14-50 garage outlet for 5 years, I began to have problems. The outlet was installed as a EV charging option by the builder. I began to occasionally see a warning that the Model Y was lowering the charge rate from the standard 32 amp charge rate to 16 amps because the charging cord was sensing high temperatures at the outlet. The car still charged but at half the charge rate, so twice as long. It would only occasionally do this. Perplexing, but I determined that I would plug the car in daily and usually would only charge for 40 or 50 miles a day. That's only charging a little over an hour. Occasionally, I would need to charge from a remaining range of 60 or 70 miles so the length of time to charge was closer to three to four hours. There's nothing in our houses that would ever require pulling 32 amps for four hours! The wall socket the builder used in the install was the cheapest thing he could buy. That's typically a Leviton or similar at a cost of less than $10.00. After 5 years of use, mine was starting to fail, showing signs of smoking and greying, possibly caused by arcing. I researched and bought a Bryant (made by Hubbel) model #9450. About 50 bucks. The spec sheet on it shows it is made for EV charging. Although it fit the existing outlet box, it is bigger and heavier duty compared to the original. Because of this, I had to buy and install a bolt on extender and new larger faceplate for the standard metal box that held the original. Home Depot or Lowes carries those, or your electrician can provide it if he is told ahead of his house call. I thought I was okay with no problems for a couple years, but it was a false sense of security. Be safe!
Skipcam
Beware of NEMA 14-50 cheap plugs
After using a NEMA 14-50 garage outlet for 5 years, I began to have problems. The outlet was installed as a EV charging option by the builder. I began to occasionally see a warning that the Model Y was lowering the charge rate from the standard 32 amp charge rate to 16 amps because the charging cord was sensing high temperatures at the outlet. The car still charged but at half the charge rate, so twice as long. It would only occasionally do this. Perplexing, but I determined that I would plug the car in daily and usually would only charge for 40 or 50 miles a day. That's only charging a little over an hour. Occasionally, I would need to charge from a remaining range of 60 or 70 miles so the length of time to charge was closer to three to four hours. There's nothing in our houses that would ever require pulling 32 amps for four hours! The wall socket the builder used in the install was the cheapest thing he could buy. That's typically a Leviton or similar at a cost of less than $10.00. After 5 years of use, mine was starting to fail, showing signs of smoking and greying, possibly caused by arcing. I researched and bought a Bryant (made by Hubbel) model #9450. About 50 bucks. The spec sheet on it shows it is made for EV charging. Although it fit the existing outlet box, it is bigger and heavier duty compared to the original. Because of this, I had to buy and install a bolt on extender and new larger faceplate for the standard metal box that held the original. Home Depot or Lowes carries those, or your electrician can provide it if he is told ahead of his house call. I thought I was okay with no problems for a couple years, but it was a false sense of security. Be safe!
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@Skipcam, do you routinely unplug the EVSE at the outlet? My guess is that those original residential grade outlets cannot sustain too many of those plug/unplug cycles. Also, the arcing may be signs of unplugging while charging.
Your replacement outlet is much more robust, I'm sure. But try to shut things off before unplugging if that's what you may have done.
Your replacement outlet is much more robust, I'm sure. But try to shut things off before unplugging if that's what you may have done.
It is true that some of the lower grade 14-50 receptacles aren't up to snuff with EVs. There are plenty of folks who have had one burn up like OPs, yet they never unplugged it since the day it was installed.
In searching for which brand, I actually discovered that some have an EV right on the receptacle itself.
KOT
In searching for which brand, I actually discovered that some have an EV right on the receptacle itself.
Leviton 50 Amp 125/250 Volt EV Power Outlet/Receptacle, NEMA 14-50R, Black 1450R (1-Pack) R10-1450R-0B0 - The Home Depot
Complement the beauty and elegance of your living space by choosing this impressive Leviton EV Charging Receptacle Outlet HeavyDuty.
www.homedepot.com
KOT
Eight years ago, I installed a 14/50 in my garage myself. I used the least expensive plug, box and breaker that Home Depot sells. I installed these materials correctly. The box is mounted on all four corners and the connections are tight and checked periodically. I would guess that I've had around 100 plug/unplug cycles over the eight years. No issues, no warnings, no overheating, no problems AT ALL.
Meanwhile, my daughter had an electrician install her 14/50 with upgraded materials. Problems from day one. Overheating and reduced charging speeds. I went and remounted the box and tightened all connections. Problem solved.
IMHO, faulty installs are most often the fault of the installer, not of the materials used. Like most tradesmen, electricians are selling their time, and many are looking to get in and out as quickly as possible. Their goal is not always compatible with a high-quality job. Be more concerned with who you hire rather that what materials they use.
Meanwhile, my daughter had an electrician install her 14/50 with upgraded materials. Problems from day one. Overheating and reduced charging speeds. I went and remounted the box and tightened all connections. Problem solved.
IMHO, faulty installs are most often the fault of the installer, not of the materials used. Like most tradesmen, electricians are selling their time, and many are looking to get in and out as quickly as possible. Their goal is not always compatible with a high-quality job. Be more concerned with who you hire rather that what materials they use.
Leviton has only recently began selling this heavier duly model. If you’re buying it your self, you are good to go. But they still sell the cheaper, less heavy duty model. You need to check that your builder or installer is putting in the the best heavy duty unit they can.
It is true that some of the lower grade 14-50 receptacles aren't up to snuff with EVs. There are plenty of folks who have had one burn up like OPs, yet they never unplugged it since the day it was installed.
In searching for which brand, I actually discovered that some have an EV right on the receptacle itself.
Leviton 50 Amp 125/250 Volt EV Power Outlet/Receptacle, NEMA 14-50R, Black 1450R (1-Pack) R10-1450R-0B0 - The Home Depot
Complement the beauty and elegance of your living space by choosing this impressive Leviton EV Charging Receptacle Outlet HeavyDuty.www.homedepot.com
KOT
The default maximum charging current for Tesla models is 48A, but this can be reduced by the vehicle, EVSE, or user.
Before charging begins, the EVSE tells the vehicle what the maximum available charging current is and it ramps up to that value from 0A while measuring voltage drop, which if more than 12% reduces the maximum charging current by 25%.
The Wall Connector allows for a maximum of 48A depending on how it is commissioned.
The Mobile Connector allows for a maximum of 32A depending on the plug adapter being used.
The vehicle remembers the maximum charging rate by location. For example, you can set it to 16A at home and 32A at work and 48A at grandma's house.
16 amps is the default number for the charger when it senses overheat. Usually always from a plug outlet issue. Surprised you got 5 years out of your plug. I had same issue with a Leviton after a year, replaced it with a Hubbell and has worked great for over five years. You should be good to go now. Be safe for sure, don't cheap out on the wiring or the plug for EV charging.
Having the correct equipment to charge an EV day after day is critical. The well respected Sandy Munro did a video about this and it is well worth your time to view it. Basically daily charging an EV should be professionally viewed as a continuous duty appliance and not an occasional one-off task. Also the plug needs to be robust enough to allow for repeated plugging and unplugging cycles.
I had the same problem with my Leviton 14-50 overheating and causing the charge rate to drop. I also replaced it with a Bryant a couple of years ago and it has been fine since.
I never had an issue until I moved to Florida. Only happens in the summer. When it's HOT. My garage definitely gets over 100 F.
Started up again with the reduced charging.... Don't think it requires a new plug, maybe just a way to cool the garage.
Started up again with the reduced charging.... Don't think it requires a new plug, maybe just a way to cool the garage.
You bring up a common issue, although it's not the fault of the "plug" as you state, but the Outlet as you show. Fires have started because of cheap outlets. Not only that, besides the danger of it, the excessive heat generated by small contact surface is also costing you energy. The best way is to hard wire your chargers. I happen to use a Mobile Connector because I don't need anything faster so I do use the outlet, but I use a good one. Stick to Hubbell, Bryant, Eaton (WD125), or Leviton (8375).
Hi. There is a great solution for this. Even though the 14-50 is a code compliant selection, the typical outlet you reference is normally for appliances that dont have sustained loads for hours on end. Like a dryer. There is a great solution. Legrand has an EV charging rated NEMA receptacle. Check it our here 50A Weather-Resistant Electrical Outlet for EV Chargers | Power Outlets | Outlets and Receptacles | Wiring Devices
These have more rugged terminals and higher temp plastics to handle the heat from long charging sessions at high amperage. There is no code requirement for this, yet, but the inspectors are pushing for a better solution. These are weather resistant too. Great for outdoor installation in proper enclosures.
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These have more rugged terminals and higher temp plastics to handle the heat from long charging sessions at high amperage. There is no code requirement for this, yet, but the inspectors are pushing for a better solution. These are weather resistant too. Great for outdoor installation in proper enclosures.
I replaced my electric dryer circuit with an inexpensive 14-50 outlet. Since I did the work myself, I saw that the circuit breaker was rated at 30 amps. Moreover, so was the installed wiring.
The thing is, even though the breaker is rated for 30 amps, the National Electric Code (NEC) says to run a circuit at 80% of full load if the load runs for longer than 3 hours. Hence, I set my M3 to only pull 24 amps when I charge at home. I then waited for 3 hours of charging and placed my hand on the plug. It wasn't discernably warm nor was the conduit nor was the plug housing so I reckoned even though I didn't spring for $90 outlet, I wasn't creating a hazard.
I've experimented with the load setting and at 27 amps (90%) the plug is slightly warm. Reckoning that slightly warm over the years might not be good for the plug, I've dialed it back.
tl;dr Don't pull more than 80% of the circuit breaker's rating.
The thing is, even though the breaker is rated for 30 amps, the National Electric Code (NEC) says to run a circuit at 80% of full load if the load runs for longer than 3 hours. Hence, I set my M3 to only pull 24 amps when I charge at home. I then waited for 3 hours of charging and placed my hand on the plug. It wasn't discernably warm nor was the conduit nor was the plug housing so I reckoned even though I didn't spring for $90 outlet, I wasn't creating a hazard.
I've experimented with the load setting and at 27 amps (90%) the plug is slightly warm. Reckoning that slightly warm over the years might not be good for the plug, I've dialed it back.
tl;dr Don't pull more than 80% of the circuit breaker's rating.
I'm a big fan of reading the Owners Manual. The Tesla Owners Manual does not speak in detail about the questions you raise. I believe Tesla's omission on the matter is because it does not make a material difference to the strain on, or the longevity of the battery. However, the owners manual does reference the time to charge which is most likely because Tesla considers the amount of consumer enjoyment to be highly correlated with the time to complete a charge session.
https://www.tesla.com/ownersmanual/modely/en_us/GUID-BEE08D47-0CE0-4BDD-83F2-9854FB3D578F.html
Nope. Degradation is more closely tied to the length of time spent charging than it is to charging rate. See this post for a video where Professor Jeff Dahn explains this.
At AC charging rates (as opposed to DC fast-charging/supercharging rates), you're going to lose power from the various equipment involved with charging the car (inverters, computers, etc). Those losses are mostly "fixed", and don't vary much by the rate of charging. Therefore, to minimize those losses, you'll want to complete charging as quickly as possible.
In the end, these differences are fairly minor. But you aren't the only one under the mistaken assumption that AC charging more slowly is generally better.
Valid point for solar; otherwise, peak usage isn't relevant since residential billing is not based on demand.
If it's Square D SQR46501BK (or any other model of Square D, since I don't believe they make an NEMA 14-50 receptacle that is suitable for EV charging), it should be immediately replaced with a Bryant 9450FR or equivalent or better which will also require a new faceplate because the "correct" receptacles are slightly larger.
I choose to have a hard-wired charger, no plug. The one I choose is Emporia which gives options of plug or hard-wire (hardwire whip). They have phone apps and it works with their energy monitor systems for the house.
Emporia Level 2 EV Charger | NACS (Tesla) or CCS (J1772) – Emporia Energy
Emporia Level 2 EV Charger | NACS (Tesla) or CCS (J1772) – Emporia Energy
I can't figure out why so many of you are charging your EVs through plugs and outlets. Just hardwire a Wall Unit and be done with it. Outlets cost money, so do the GFCI circuit breaker they require by code.
It costs nothing to hardwire the feed directly to the Wall Unit. The best part is no part.
It costs nothing to hardwire the feed directly to the Wall Unit. The best part is no part.
Thinking of upgrading to a 90 AMP wall charger.
Our 50 AMP Emporia is colossal, especially since they improved the confusing app, but what bragging rites with the 90 AMP feeding the GMC's 205 claimed, 212 in testing battery packs.
When I shake anyone's hand I'll say "You have a handshake just like the electrician that installed our 90 AMP EV wall charger."
Wife thinks when she plugs it in the whole neighborhoods homes lights might dim like the prison lights when they executed James Cagney on the electric chair in Angels with Dirty Faces.
Our 50 AMP Emporia is colossal, especially since they improved the confusing app, but what bragging rites with the 90 AMP feeding the GMC's 205 claimed, 212 in testing battery packs.
When I shake anyone's hand I'll say "You have a handshake just like the electrician that installed our 90 AMP EV wall charger."
Wife thinks when she plugs it in the whole neighborhoods homes lights might dim like the prison lights when they executed James Cagney on the electric chair in Angels with Dirty Faces.
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