240v through the 5-15 plug?

[Electric Joe]

Does anyone know what happens if you use both flat prongs of the Tesla NEMA 5-15 plug adapter with hot wires to effectively send 240v through the UMC? I'm too chicken to try it. I figure the UMC might see the 240v and use it at up to 15 amps, or it might self-destruct because it was expecting only 120v since the 5-15 adapter was detected.

I ask because I have access to a 240v low amp outlet at work and I'm wondering if I can make a simple adapter that the UMC's 5-15 would plug into.

 

[Sparky]

It sounds like you want a 6-15 adapter, which Tesla sells. If so, I recommend buying that.
Then, you should be able to pull 12A at 240V.
However, I've successfully used a Tesla NEMA 5-20 adapter (one sideways plug) in a 240V NEMA 240 20A outlet (6-20?). It was a garage outlet that has a whole-house vacuum which runs on 240V.
The Tesla EVSE seems to only care about current limits for the particular adapter not the 120 or 240 voltage. I used the 5-20 since I couldn't get a 6-20 at the time and I wanted the current to limit at 16A max.

 

[davewill]

It will work fine with the car pulling 12a @ 240V. The 6-15 adapter is available and would be better choice to accomplish the same thing. Some people use the 5-20 adapter at 240v as that is the only path to getting 16a @ 240v.

 

[Barry]

Bad idea to use a 5-15. Bad stuff can happen by accident. Reminds me of a trip to eastern Europe about 15 years ago where I saw the standard, round prong, 240VAC connector being used for headphones!

 

[SomeJoe7777]

The UMC will have no problem with it, but 5-15 outlets aren't tested or rated for 240V. Could be a hazard. And it's not code-compliant, of course.

Like others have said, better to use a 6-15 outlet and adapter.

 

[⚡️ELECTROMAN⚡️]

I would strongly suggest you get the proper adapter. They are only $45. It's not like the parts to build an adapter are free. I'm an electrician and I have the spare parts lying around collecting dust. I was going to make a 6-15 adapter that the 14-50 Tesla adapter can plug into. That way I can set the charging amperage to 12A for a 6-15 outlet and 16A if I'm plugging into a 6-20 outlet. I'm only making the adapter to have on hand for very rare occasions. That sounds a little sketchy to use the 5-15 for 240 volts, though. I would buy the proper adapter from Tesla if I was going to be using it on a daily basis. Especially if I was plugging into an outlet at work.

 

[miimura]

Overseas, I have seen regular 5-15 type outlets labeled as 240V and it frankly scares me. There is a reason that we have sockets that mechanically differentiate for voltage.

Any home-made adapter that adapts one socket to another like 6-20 to 5-20 should be clearly labeled and kept in the car when not in use. Since there is a Tesla adapter for 6-15, it should be used with a proper 6-15 socket instead of re-wiring a 5-15 socket to 240V or using a third party or home-made adapter.

 

[n2mb_racing]

Here you go, easiest option:
Tesla — NEMA 6-15

Though, you can get slightly faster charging (11 mi / hr vs 8 mi / hr) and about 3% higher charging efficiency by charging at 240V @ 16A using the NEMA 5-20 UMC adapter, but then you'd have to make a custom adapter.

 

[Aphinity]

In case anyone isn't aware of this and is reading this thread well after it was posted (like me), the only concerns you have using a 5-15 connector with 240V are the following:

• Can the mobile connector accept two hot wires (120V in dual phases) on a 5-15 connector (i.e. is it wired to accept this internally)
  
• Amperage pulled through the line does not exceed original specs of 5-15 connector (i.e. 15 amps)

Since @davewill above confirmed that the mobile adapter can take 240V through the 5-15, then there is no reason to buy another adapter if you're being mindful of your wiring.

The mobile connector will restrict you to 15 amps, which is safe for the wiring, and if there happens to be 240V at the hot and neutral, it should just work as if you had a Tesla 6-15 connector on it. The real risk is you might accidentally plug in a 120V only plug into your now 240V outlet without thinking. THAT is the real danger. There is no electrical or physical reason that this setup is dangerous; it's just the idiot factor you have to worry about.

I plan to do this for wiring in a 15 amp 240V using both phases from two different 120V outlets in my rental suite. I've done this before to use a european 2400W 240V water kettle and it's been perfectly safe for about 3 years. My reason for using the 5-15 is because I need to run a heavy duty 15A rated industrial extension cord in order to reach my car, and it has a 5-15 on both ends. I could buy a 6-15 to be safer, but in the end, I'm adapting from 5-15 anyway, so it's not really any safer. I plan to label my extension cord very clearly. I use this cord for normal 120V tasks on normal outlets so I don't want to cut it.

Again, you have to be CAREFUL with this kind of thing, and be absolutely sure what you're doing. It can be dangerous and you might fry something, so don't do it. If you're in doubt, talk to an electrician, or just buy the right adapter from the Tesla site.

 

[n2mb_racing]

Yeah, I did this for a while, using a 5-20 extension cord and 5-20 UMC plug on 240V. But, I wired the house with a 6-20 outlet and made an adapter.

But, now that Tesla offers 6-20 UMC plug, it's much neater to go direct.

B.t.w. you can get 6-20 extension cords, then everything will be legit.

I am also considering the 6-50 extension cords and 6-50 UMC plug, since they are much thinner and more flexible than the 14-50 extension I have now. They can be thinner since they only carry the 3 needed wires, and omit the neutral that the UMC doesn't use anyway. I might try that if we ever travel to a rental again, and get an adapter from 14-30 to 6-50 to be able to plug into a dryer outlet. Of course, you still have to manually limit current to 24A, but other than that, seems like a good setup.

 

[Electric700]

The UMC will have no problem with it, but 5-15 outlets aren't tested or rated for 240V. Could be a hazard. And it's not code-compliant, of course.

Like others have said, better to use a 6-15 outlet and adapter.

Yes, or a 6-20 if the wiring supports it (or put in new wiring). You can order an adapter here:

Gen 2 NEMA Adapters

Since you'd need a new 2-pole breaker, you could also get a whole house surge protector like one of the ones below if you don't have one already:

GE Whole Home Surge Protection Unit-Panel Mount-THQLSURGE - The Home Depot

Square D QO 22.5 kA 2-Pole Surgebreaker Surge Protective Device-QO2175SB - The Home Depot

 

[n2mb_racing]

Since you'd need a new 2-pole breaker, you could also get a whole house surge protector like one of the ones below if you don't have one already:

GE Whole Home Surge Protection Unit-Panel Mount-THQLSURGE - The Home Depot

Square D QO 22.5 kA 2-Pole Surgebreaker Surge Protective Device-QO2175SB - The Home Depot

Do you think those surge protectors could actually work? Given how small they are and how much energy they'd need to absorb to be useful....

 

[MN-MS100D]

SPD's do not absorb energy. The most common varieties are MOV-based that start conducting from Line to Neutral when (and only when) a surge is present. Commercial units protect all phases to neutral and neutral to ground. Lightning strikes are always a gamble, and unplugging your EV and unplugging the UMC is always best policy before the storm hits.

 

[Aphinity]

The UMC will have no problem with it, but 5-15 outlets aren't tested or rated for 240V. Could be a hazard. And it's not code-compliant, of course.

Like others have said, better to use a 6-15 outlet and adapter.

To be clear, electrically, 240V vs 120V vs 10v is no different in terms of safety on the wire or connector. Amperage is all you need to worry about. That is what heats up (and melts) connectors and wires, not voltage. Once you get into the thousands of volts, then you need to worry about arching, but that's not what we're discussing.

Outlets are keyed as they are (5-15 vs 6-15) to avoid the idiot factor; people plugging in the wrong device to the wrong voltage. If you're being careful, physically, there is no danger to using a 5-15 for 240V. Just be sure of what you're plugging in.

 

[eladts]

To be clear, electrically, 240V vs 120V vs 10v is no different in terms of safety on the wire or connector. Amperage is all you need to worry about. That is what heats up (and melts) connectors and wires, not voltage. Once you get into the thousands of volts, then you need to worry about arching, but that's not what we're discussing.

Outlets are keyed as they are (5-15 vs 6-15) to avoid the idiot factor; people plugging in the wrong device to the wrong voltage. If you're being careful, physically, there is no danger to using a 5-15 for 240V. Just be sure of what you're plugging in.

You can be as careful as you want, it won't prevent someone else plugging in a 120V device to the hacked 240V NEMA 5-15 socket. The rules of the electrical codes are there for a reason. It is silly to take that risk just to save less than $50 for the proper NEMA 6-15 socket and the NEMA 6-15 Tesla adapter.

 

[n2mb_racing]

You can be as careful as you want, it won't prevent someone else plugging in a 120V device to the hacked 240V NEMA 5-15 socket. The rules of the electrical codes are there for a reason. It is silly to take that risk just to save less than $50 for the proper NEMA 6-15 socket and the NEMA 6-15 Tesla adapter.

Agreed, now that it exists. I think when this thread was started, there was no NEMA 6-15 or 6-20 plug....

 

[Aphinity]

It's also silly to use a 10-30 tesla-provided connector, considering the wiring for a 10-30 usually omits ground, causing a serious safety hazard in wet conditions. So, let's just agree to disagree on this one. If you're paying attention, there is no safety problem, so be sure to pay attention.

Particularly true since nearly all devices now with a power adapter or internal power supply will take 240v with no harm. It's only 'dumb' devices, like lights, motors, or heating elements that would have an issue, and would just pop the breaker.

 

[Electric700]

You can be as careful as you want, it won't prevent someone else plugging in a 120V device to the hacked 240V NEMA 5-15 socket. The rules of the electrical codes are there for a reason. It is silly to take that risk just to save less than $50 for the proper NEMA 6-15 socket and the NEMA 6-15 Tesla adapter.

Exactly.

 

[Rocky_H]

It's only 'dumb' devices, like lights, motors, or heating elements that would have an issue, and would just pop the breaker.

blow up the appliance you mean...which could catch your carpet or something else on fire inside your house...and/or injure the person plugging it in. Oh, and then it probably would also have a short from the melted pieces...which would then probably trip the breaker. Don't wire the wrong voltage onto an outlet on purpose.

 

[eladts]

Agreed, now that it exists. I think when this thread was started, there was no NEMA 6-15 or 6-20 plug....

Even before the Tesla NEMA 6-15 or 6-20 adapters existed you shouldn't have wired a NEMA 5-15 or 5-20 with 240V. You could have bought some adapter that convert NEMA 6-15 or 6-20
to NEMA 5-15 or 5-20 and keep it in the car. That would minimize the risk of someone plugging a 120V device to a 240V socket. You could have also bought a non-Tesla EVSE with a NEMA 6-15 or 6-20 plug.

blow up the appliance you mean...which could catch your carpet or something else on fire inside your house...and/or injure the person plugging it in. Oh, and then it probably would also have a short from the melted pieces...which would then probably trip the breaker. Don't wire the wrong voltage onto an outlet on purpose.

You would also be personally liable to all the damages and injuries once the investigator from you insurance company finds out what you did.