Debating gas or electric on our first vacation since buying my Mach-E

mixduptransistor

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The house has washer/dryer, but on 3rd level. Looked at 240v extension cords, are these safe?
Generally, yeah, you'll be fine. The larger the gauge of the wire the better, both in terms of safety (won't overheat/melt/catch fire) and in terms of power loss (the heat generated is you losing power over the length of the cord)

I've used a very hefty 50 amp/240v extension cord with my former Tesla many times and it's fine

One thing to note, though, is that the dryer outlet very likely may be 30 amps, so don't just blindly plug in your 50 amp mobile charger. You'll need some way to get the car to bump down to 30 amps, probably with a different EVSE (you could do this in car with Tesla, but not with the Mach E). You may also need a physical plug adapter to go from the 30 amp outlet to whatever you end up using as your EVSE
 

mkhuffman

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They have to be from different phases.
My garage has a separate 240 panel so I could use two in there if the car fits.
Currently I am use one on the side of the house and one on the side of the garage.
That makes sense. I was pretty sure they had to be on different phases, else your converter would be pretty complicated. I guess the converter just hard wires the hot to each hot terminal, and shares the neutral and ground, right? Pretty straight forward but only if you know what you are doing. I would hate for someone to get hurt trying this, or cause a fire.

What a great idea this is!
 

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I'll be driving my Mach-E down to North Myrtle this summer, and I don't really have any qualms about it after 1 small road trip I took 2 weeks ago which went well.

There's 2 EA stations on my way, one about 80miles from the beach house. Will top up to 80% there, and use level 2's around Myrtle (Tanger Outlets seem to have free Level 2's), and/or possibly plugging in at the house if I can.

I'd assume it's common courtesy to ask the vacation rental owner if it's okay to plug your EV in, no? I haven't messaged them yet, but planning on asking just to be sure.
 

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You'll need some way to get the car to bump down to 30 amps, probably with a different EVSE (you could do this in car with Tesla, but not with the Mach E).
This seems like an easy feature to add with an OTA update. I hope they add it because it seems like a big gap in capability compared to the competition, unless I am misunderstanding something.
 

mixduptransistor

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That makes sense. I was pretty sure they had to be on different phases, else your converter would be pretty complicated. I guess the converter just hard wires the hot to each hot terminal, and shares the neutral and ground, right? Pretty straight forward but only if you know what you are doing. I would hate for someone to get hurt trying this, or cause a fire.

What a great idea this is!
To get 240v, you connect the two phases. To get 120v you connect one phase to neutral. In a 240 circuit there is no neutral. There's no such thing as a converter without two phases. You could I guess use a transformer to bump up to 240v but as previously mentioned the amperage output would be cut in half

Modern appliances and outlets will have a neutral in addition to the two hots because modern appliances take advantage of the 120v for some internal uses, but for most EVSEs two hots and a ground are all that are needed, no neutral

It should be noted even the two phases from two 120v outlet adapter kits you can buy are not UL listed, and if they burn down your house you likely will not get your insurance to pay for it
 

mkhuffman

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To get 240v, you connect the two phases. To get 120v you connect one phase to neutral. In a 240 circuit there is no neutral. There's no such thing as a converter without two phases. You could I guess use a transformer to bump up to 240v but as previously mentioned the amperage output would be cut in half

Modern appliances and outlets will have a neutral in addition to the two hots because modern appliances take advantage of the 120v for some internal uses, but for most EVSEs two hots and a ground are all that are needed, no neutral

It should be noted even the two phases from two 120v outlet adapter kits you can buy are not UL listed, and if they burn down your house you likely will not get your insurance to pay for it
So in a 240V use case all the current flows through the hot wires and none through the neutral? That makes sense so just validating. And since that is the case, then will the 15 Amp circuit breakers work correctly when there is no current coming back through the neutral wire? I think they should because only the hot wire is connected to the breaker. The neutral is wired into the ground/neutral buss in the breaker box. At least that is how my houses have been wired.

If all that is true, then the fire risk should not be any greater than charging two EVs with two L1 chargers on different circuits. I guess UL does not rate the adapters because it is too hard to test all the different multiple outlet scenarios, especially if the breaker box is wired incorrectly. I am sure all breaker boxes are wired correctly. Ha. Incorporating a GFCI into the adapter might help. Would have to think about how that would work...
 

mixduptransistor

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So in a 240V use case all the current flows through the hot wires and none through the neutral? That makes sense so just validating
Yes. My current Tesla Wall Connector has two hots and the ground, no neutral. I am replacing it with a ChargePoint EVSE for my new Mach E connected to a NEMA 6-50 outlet (different from a NEMA 14-50) which has three prongs: two hots and a neutral. It's what ovens and dryers used to use, but now a 14-150 is standard. The 14-50 has a neutral, so that the appliance maker can use both 240v and 120v components without a transformer

will the 15 Amp circuit breakers work correctly when there is no current coming back through the neutral wire? I
Yes, as you noted breakers don't use the neutral at all anyway. It's how all breakers work

If all that is true, then the fire risk should not be any greater than charging two EVs with two L1 chargers on different circuits. I guess UL does not rate the adapters because it is too hard to test all the different multiple outlet scenarios, especially if the breaker box is wired incorrectly. I am sure all breaker boxes are wired correctly. Ha. Incorporating a GFCI into the adapter might help. Would have to think about how that would work...
If the makers of these devices wanted to get them UL listed, then UL would test them. They would fail, though, because there are significant issues. The primary one being that you can't know until you try that you have each leg on a different phase, and depending on the appliance you might kill it, or, draw too much amperage, or any other numerous ways it could go bad if you hook the thing up wrong and just leave it
 

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Yes, as you noted breakers don't use the neutral at all anyway. It's how all breakers work
This isn’t necessarily true as it pertains to new installs now, since GFCI breakers use the neutral if the 220V circuit has a neutral, which for 14-50 is required.
 

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If the makers of these devices wanted to get them UL listed, then UL would test them. They would fail, though, because there are significant issues. The primary one being that you can't know until you try that you have each leg on a different phase, and depending on the appliance you might kill it, or, draw too much amperage, or any other numerous ways it could go bad if you hook the thing up wrong and just leave it
I can think of a scenario where the hot and neutral wires are wired incorrectly in the outlet (backwards). That is not hard to do, and an inexperienced electrician (or someone pretending to be one like me) could easily make that mistake. So the adapter would now be connecting one hot phase to neutral. Then you only have 120V supplied to the appliance, which definitely could damage it. Probably it would not damage a BEV, though, because you would think the charger is smart enough to detect only 120V and charge accordingly. Interesting.

Oh yeah! If you have wired your adapter to connect neutral to neutral, and maybe even neutral to ground, when you plug into that incorrectly wired outlet you are now connecting a hot wire directly to neutral. If there are no other wiring mistakes, the breaker blows. But if there is another problem, you might cause a fire or burn the house down. Literally. No wonder UL won't approve these.
 
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mixduptransistor

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This isn’t necessarily true as it pertains to new installs now, since GFCI breakers use the neutral if the 220V circuit has a neutral, which for 14-50 is required.
You do not want to use a GFCI breaker with most (all?) EVSEs. The two that I've owned very specifically say not to use them on a GFCI protected circuit
 

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You do not want to use a GFCI breaker with most (all?) EVSEs. The two that I've owned very specifically say not to use them on a GFCI protected circuit
I have heard this with some EVSEs but Ford’s own documentation recommends one, though. Also a code requirement with the latest NEC if your jurisdiction adopts.
 

mixduptransistor

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I have heard this with some EVSEs but Ford’s own documentation recommends one, though. Also a code requirement with the latest NEC if your jurisdiction adopts.
EVSEs that tell you not to use a GFCI have one inside (which is why they tell you not to use it on the circuit) and have documentation to that effect so you would pass code
 

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