Home made charging adapters

[davewill]

Thanks for creating this.

I had a quick question. You mentioned in the PDF that you can modify a 10-50 plug to work with both the 10-30 and 10-50 receptacles.
Can you also do this mod to the 10-30 plug by using a hacksaw to remove the left side of the top pin?

I have a 10-30 cord and want to make it work for both receptacles.

I've seen that done, but you might end up with smaller blade since you have to cut off the entire curved area. You could also get a modular plug like this one that has both blades in it, then switch the blade if you need the other outlet type. I did something similar for 14-30/50/60 where I just left the neutral pin out altogether. Do you actually know of a 10-50 that you'd like to plug into? They're pretty rare.

 

[LightC]

Thanks for that info @davewill. No, I do not know of a 10-50 to plug into but figured I should have all the adapters in case the need arises.

Can you like me to the modular plug you're using for 14-30/50/60?

 

[LightC]

*like = link

 

[LightC]

wait, I already have a 14-30 cord that I will attach to a 14-50 receptacle. If I cut off the neutral on the 14-30 end, I should be able to use this for 14-30/50/60 with either the UMC or my 14-50 extension cord.

Thanks for the help.

 

[davewill]

Thanks for that info @davewill. No, I do not know of a 10-50 to plug into but figured I should have all the adapters in case the need arises.

Can you like me to the modular plug you're using for 14-30/50/60?

Leviton Commercial Thermoplastic Angle Blade Plug 14-30P/14-50P 14-6 AWG 3 Pole 4 Wire - Ace Hardware

It was actually listed under "You may also like" on the page I linked above.

P.S. Yes, cutting off the neutral on a molded plug would accomplish the same thing.

 

[Cosmacelf]

Thanks for creating this.

I had a quick question. You mentioned in the PDF that you can modify a 10-50 plug to work with both the 10-30 and 10-50 receptacles.
Can you also do this mod to the 10-30 plug by using a hacksaw to remove the left side of the top pin?

I have a 10-30 cord and want to make it work for both receptacles.

First, to the others that have replied to this question: he’s asking about a 10-50, not a 14-50. They are quite different.

And yes, you can mod the 10-30 to hack off the angled part. In fact I did that with my 10-30/10-50 adapter. I used a sawzall to cut it off.

Btw, I now keep this web site updated instead of that document: http://carcharging.us/

Same info, but more broadly applicable to more EVs.

 

[TEG]

Usual advice applies not to pass through more current than the plug/wiring is designed to handle.
If you modify a 30amp to fit in a 50amp socket, best not run 50amps through it !

( Some would probably argue that you should never use modified plugs... )

 

[HankLloydRight]

Thanks for that info @davewill. No, I do not know of a 10-50 to plug into but figured I should have all the adapters in case the need arises.

When I got my P85+ in 2014, I made all the adapters and carried them in my car for years. Along with a 14-50 extension cord. In all that time (and long before the SC network was as built-out as it is now), I used one of those adapters (6-50), once. They're all now in a crate in the garage since I got tired of them taking up a lot of space (and weight) in my trunk.

Unless you're doing a lot of road trips stopping at RV parks to charge (and especially being from Connecticut), I doubt you'd ever really need them in practical use.

On my last 3000 mile eastern-US road trip this summer, I didn't even take my UMC.

 

[Alketi]

So, I made a 50ft 14-50 extension cord for use in charging at a vacation house that has a dryer outlet about 50 feet away. I have a second 6ft extension that's 14-50 to 10-30 converter. And then I have the 20ft UMC as the last link in the chain, connected to the car with the 14-50 on the other end. (The extensions have no neutral connected)

I tried this for the first time yesterday, after previously testing all the connections.

The car immediately began charging at 32A. Somehow, even with the 14-50 attached to the UMC, the car charger knew it wasn't 50A.

Problem is, I saw 32A and was in a rush and didn't realize that this was on a 30A breaker.

The weird thing is that the 30A breaker didn't trip, but rather the car charging faulted after about 15 minutes.

I then realized my mistake and set the car to charge at 24A max. Reconnected. And the car began charging again.

After another 15 minutes the charging stopped and faulted again. I have no idea why.

I reset it again and set the max to 22A, it began but didn't have long enough to test if I made it past the 10-15 minute barrier.

Does anyone have an idea why this would be faulting at the car after 10-15 minutes? The voltage was in the 230s. What could the UMC be sensing?

(This is on a Model 3 with the new UMC)

 

[TexasEV]

1. The car started charging at 32A because you used the 14-50 adapter. That's what the Gen 2 UMC charges at with a 14-50 outlet, not 40A as with the Gen 1 UMC. (It should never charge at 50A on a 50A circuit!)
2. The car probably sensed voltage drop from the extension cords and stopped charging.
3. Your forgetting to manually set the amps down is why these homemade kludge setups are dangerous. If you insist on using an extension cord, make one for a 10-30 outlet and use the UMC 10-30 adapter. Then it will automatically set the amps to 24A.

 

[Cosmacelf]

On my last 3000 mile eastern-US road trip this summer, I didn't even take my UMC.

OK, now you're just showboating

I do agree that most people who travel don't need these. For me personally, I hate having to rely on a Supercharger if I can charge at my destination. So I have used the following for destination charging:

Included J1772 adapter and included 14-50 adapter
NEMA 5-20 (42% faster charge than a regular 120V receptacle!)
TT-30 (horse jumping show grounds)
50A circuit breaker (I just stuffed it into a rented condo's electrical panel, worked great).
Dual 120V combiner for 240V charging (have to really hunt around inside the condo for two appropriate plugs!)

But nothing else. And frankly, your average person wouldn't do the last three. I do recommend the 5-20 adapter though...

 

[Cosmacelf]

So, I made a 50ft 14-50 extension cord for use in charging at a vacation house that has a dryer outlet about 50 feet away. I have a second 6ft extension that's 14-50 to 10-30 converter. And then I have the 20ft UMC as the last link in the chain, connected to the car with the 14-50 on the other end. (The extensions have no neutral connected)

I tried this for the first time yesterday, after previously testing all the connections.

The car immediately began charging at 32A. Somehow, even with the 14-50 attached to the UMC, the car charger knew it wasn't 50A.

Problem is, I saw 32A and was in a rush and didn't realize that this was on a 30A breaker.

The weird thing is that the 30A breaker didn't trip, but rather the car charging faulted after about 15 minutes.

I then realized my mistake and set the car to charge at 24A max. Reconnected. And the car began charging again.

After another 15 minutes the charging stopped and faulted again. I have no idea why.

I reset it again and set the max to 22A, it began but didn't have long enough to test if I made it past the 10-15 minute barrier.

Does anyone have an idea why this would be faulting at the car after 10-15 minutes? The voltage was in the 230s. What could the UMC be sensing?

(This is on a Model 3 with the new UMC)

Yes, this is exactly what I would expect to happen.

First, your new UMC only charges at a maximum rate of 32A, even on the 50A circuit.

Second, breakers don't trip right away when loads are slightly exceeded. People think breakers trip right away, but they generally only
do that for short circuits. For slightly overloaded conditions, they just get hot until they eventually trip from heat. The UMC was sensing increased resistance from a wire/breaker that was getting hot. That's some seriously good engineering there from Tesla's part since the breaker should probably have tripped somewhere in that 15 minutes (but not guaranteed to). The reason it faulted again is that the breaker/wire was still hot. 24A is still a significant load and the breaker/wire didn't have time to cool down, hence the second fault.

Let things cool down and it should all work at 24A.

 

[Alketi]

Yes, this is exactly what I would expect to happen.

First, your new UMC only charges at a maximum rate of 32A, even on the 50A circuit.

Second, breakers don't trip right away when loads are slightly exceeded. People think breakers trip right away, but they generally only
do that for short circuits. For slightly overloaded conditions, they just get hot until they eventually trip from heat. The UMC was sensing increased resistance from a wire/breaker that was getting hot. That's some seriously good engineering there from Tesla's part since the breaker should probably have tripped somewhere in that 15 minutes (but not guaranteed to). The reason it faulted again is that the breaker/wire was still hot. 24A is still a significant load and the breaker/wire didn't have time to cool down, hence the second fault.

Let things cool down and it should all work at 24A.

Ahh of course! The UMC is limited to 32A. I remember reading that a long time ago but had forgotten.

Thank you for the explanation. So I would guess the voltage would have been dropping and that's what the UMC would have sensed. I saw that the UMC voltage was about 233V soon after the initial connection but did not observe it over time.

Thanks again.

 

[gibbyj]

Just want to say my thanks for this good article. I like to use destination charging at Airbnb houses. Convenient for nightly charging on multi-day vacations, a little better for the car, and cuts down on the length of the drive. I can arrive at a destination with only 7%, with no (few?) worries. I generally check ahead of time with the Airbnb host, getting permission, finding out out what they have. I made a 46 ft SOW extension cord; I found that it can be a LONG way from stove/dryer outlet out to where car is. My ext cord happens to be 1/2 10ga and 1/2 12ga, so I see 3 or 4v drop, at 32a. Not much drop at 24a. Weird cord, but it's lighter than one made all with all 10ga. I probably should restrict myself to 24a with this cord even with 50a outlet, but at least I can feel the cord to see how warm it's getting. I used a dryer plug on it, but removed the neutral blade so it works with 14-30 and 14-50 (and 14-60, if I ever found one of those). The article makes all this nice and clear. I bought quite a few different plugs for hotels, camping etc., but didn't bother to make the adapters. If/when I need one, I will change the plug on my ext. cord at my destination; should be less than 15 min job, and may never even need to do it. Doesn't weight that much to carry a few plugs. Embarrassing story: I plugged into a 14-50 dryer outlet at one destination and pulled 32a, assuming incorrectly that 14-50 outlet meant thick service wire. Should have set car for 24a. Things got hot and the UMC failed out as it should have; pretty sure it sensed the heat coming down the short conductor to the 14-50. (This time I was not using my long ext cord.) Even after setting to 24a, it still had problems b/c the 14-50 outlet had rust/bad connection inside. Turned off breaker, took it apart and improved things a little; finally worked OK. So it can be a tricky, risky business. Be VERY careful with these things. I could have burned the place down. Current situation is way not optimal. Hopefully in a few years, most destinations will provide an inspected, correctly wired 14-50 outlet that safely supports 40a continuous.