Sudden slow charging off NEMA 6-50 solved.

[n2fooz]

I'm posting this as a reference to anyone that has this problem currently or in the future.
I have a NEMA 6-50 50A outlet in my garage that I use to charge. I had this outlet already for my welder, plasma cutter, and table saw. It's worked great for a year, charging at 32A. A week ago or so, I found that my car wasn't charged to my set charge limit by my scheduled departure. It took me a couple days to realize something was wrong. I don't charge everyday, and when I noticed it, I figured maybe I forgot and didn't charge last night. Over the weekend, I pulled it off the charger 2 hrs after my normal departure time and it still wasn't completely charged. This made me investigate further. According to Teslafi, my car was starting to charge at 32A, but then it dropped to 16A after 20-30 min. After more troubleshooting I found that the plug itself was getting hot, a sign of a poor connection in the outlet. It turns out, the connector in the right slot was not making good contact because it was no longer tight. This may have been caused by something I plugged into it (which I'm now going to keep an eye on) or just a faulty outlet. Once replaced, I was back to a consistent 32A charge.

 

[davewill]

Yeah, you're not the first to be bitten by Leviton outlets. Both the 14-50 and 6-50 outlets are of questionable build and design quality. Hope you replaced it with something better. Hubbel and Bryant are the goto ones on here.

Here's a link to a thread about the 6-50 outlets:

NEMA 6-50 outlets: Leviton versus Bryant

So I had a pre-existing 40A circuit with a Leviton 6-50 outlet with a 30A EVSE plugged into it for a previous EV. It worked fine with no problems then. That EVSE was not very reliable for the Model 3, so I put the (then included) mobile connector with 6-50 plug adapter in it. Worked fine for...

teslamotorsclub.com

 

[n2fooz]

Thanks for the link. I just replaced it with another Leviton but I think I'm going to switch it out with the Hubble. Unfortunately it's up to $99 now.

 

[kingstar]

Thanks for the link. I just replaced it with another Leviton but I think I'm going to switch it out with the Hubble. Unfortunately it's up to $99 now.

Check out the Bryant versions. They are pretty much exactly the same, but generally much less expensive.

 

[kingstar]

Check out the Bryant versions. They are pretty much exactly the same, but generally much less expensive.

Although, reading some in the link given above, it seems the 6-50 may not be exactly the same like the 14-50's are.

 

[3sr+buyer]

Thanks for the link. I just replaced it with another Leviton but I think I'm going to switch it out with the Hubble. Unfortunately it's up to $99 now.

If you look into the plug holes in the Leviton outlet, you will see that the contacts are steel and touch only about half of the plug blades. This results in higher resistance than if the contacts are brass and touch the entire plug blades, which seems to be the case for all or almost all other 6-50 outlets that have been mentioned. The higher resistance makes the Leviton outlet marginal at 32A, resulting in high temperature at the plug which can cause the Tesla mobile connector to detect and overheating condition and reduce charging amperage, particularly during warm weather. Having only half size contacts also makes it more vulnerable to problems if the internals of the outlet get loose (apparently what you noticed).

Yes, Hubbell and Bryant outlets are favored on these forums, but most other outlets with brass full size contacts to the plug blades should be a substantial improvement over the Leviton outlets for this problem. Beware that many posters write about outlet preferences based on size, weight, and cost, but these are not relevant to the actual problem that Leviton outlets have (the plug blade contact issue).

For 14-50 outlets, Hubbell and Bryant outlets also have a more secure and mistake-resistant plate clamp of the wires, but the Bryant 6-50 outlet does not have this feature; it has screw down wire clamping like most other outlets. Just be careful with installation with screw down wire clamping.

 

[n2fooz]

Thank you all. I have a Hubble arriving in the next couple of days and I'll evaluate it when it arrives.

 

[n2fooz]

Thank you all. I have a Hubble arriving in the next couple of days and I'll evaluate it when it arrives.

Here are some Leviton vs Hubble 6-50r pics.

Leviton $11.73 Home Depot
Leviton claims brass double wipe contacts. If they are brass they are tinned since as you can see they are silver. The contacts themselves are smaller than the Hubble.
Operating Temperature: -40°C to 60°C (the plate says 75C but their specs say 60C)
https://www.leviton.com/en/products/5374

Hubble $49.95
Much nicer tooling and build quality.
Larger brass double wipe contacts. The screw down contacts themselves have a smaller diameter but the terminal has more brass where the wire contacts.
Operating Temperatures - Maximum continuous 75°C, minimum -40°C (w/o impact)
https://www.hubbell.com/hubbell/en/Products/Electrical-Electronic/Wiring-Devices/Straight-Blade-Devices/ConstructionCommercial-Receptacles/Straight-Blade-Devices-Receptacles-RTP-Industrial-Grade-2-Pole-3-Wire-Grounding-50A-250V-6-50R-Black-Single-Pack-/p/1636620

The Hubble is 4x the cost but is definitely on a different level as far as build quality and overall quality.
I'm going to post this in the other thread as well.

 

[3Volts2aTes]

Nice, thanks for both the information and the pictures. Definitely a better built piece. I have a Leviton that I used in the original install, but I have been keeping an eye on it. Either when it shows an issue, or when I slow down and have time I will probably swap it out. I am planning on going ahead and ordering the Hubble and having it sitting on the workbench. That will make it more likely to happen.

 

[Gauss Guzzler]

No need for those Tesla-taxed Hubble/Bryant's when Lowes stocks a perfectly decent industrial grade socket for $11

You shouldn't shop at Home Depot anyway -- all proceeds go towards overthrowing the US government.

 

[n2fooz]

No need for those Tesla-taxed Hubble/Bryant's when Lowes stocks a perfectly decent industrial grade socket for $11

You shouldn't shop at Home Depot anyway -- all proceeds go towards overthrowing the US government.

I'll stick with the Hubble and will continue to shop at Home Depot. Thank you.

 

[pikeman]

Leviton isn’t the company it used to be . . .

 

[iwannam3]

Thanks for the link. I just replaced it with another Leviton but I think I'm going to switch it out with the Hubble. Unfortunately it's up to $99 now.

$99 is cheap insurance compared to burning garage/car/house down. The cheap ones are OK for intermittent use, a welder will have a 10 to 20% duty cycle but a Tesla can pull hard for 5 continuous hours.

 

[father_of_6]

Every time I see one of these threads I feel better about having a hard-wired HPWC. Higher amperage, too. The faster charging doesn't make a practical difference to me, but psychologically it does

 

[Gauss Guzzler]

Yeah, I think Tesla was wise to omit the mobile charger and drop the wall charger price. Hardly anyone used the mobile charger for its intended "mobile" purpose, and it was just too tempting to use the "free" charger on a "simple" outlet instead of shelling out half a grand for a wall unit.

Now your $400 goes directly to Tesla for a wall charger instead of to some shady price gouging electric supply company for an outlet and a box and a faceplate and a GFCI breaker and...

 

[3Volts2aTes]

Yeah, I think Tesla was wise to omit the mobile charger and drop the wall charger price. Hardly anyone used the mobile charger for its intended "mobile" purpose, and it was just too tempting to use the "free" charger on a "simple" outlet instead of shelling out half a grand for a wall unit.

Now your $400 goes directly to Tesla for a wall charger instead of to some shady price gouging electric supply company for an outlet and a box and a faceplate and a GFCI breaker and...

Interesting that you assume all outlet boxes and plates are being used simply for mobile chargers and people who don't buy a dedicated wall unit....

 

[n2fooz]

$99 is cheap insurance compared to burning garage/car/house down. The cheap ones are OK for intermittent use, a welder will have a 10 to 20% duty cycle but a Tesla can pull hard for 5 continuous hours.

I agree. Actually I was mistaken. The 14-50 is $99 but the 6-50r is around $50.
I originally put my 6-50r outlet in, years ago, for my welder, plasma cutter, and table saw. It's fortunate that I can use it to charge my car.