Does anyone charge from a regular wall outlet?

[eprosenx]

So I am going to ask a question that I think is going to result in two things:
1. Everyone knowing that I am NOT an electrician
2. Everyone saying "noooooo, do don't that!"

So here goes:
If I have a regular outlet (what I have now learned is a NEMA 5-15), can I simply change this outlet to be a NEMA 6-15 outlet? It's the same amperage (and I can see in my panel that it's a15 amp breaker), but would result in more voltage and higher charging. I would need to buy the adapter, but this would seem to be a much cheaper way to increase my charging speed.

Electrical context: My garage has a garage door opener, but that's not plugged into the outlet I would be using, but rather another one. They are all on the same breaker though, I think.

Let the noob condemnation rain down! .

Yeah, if there is only one circuit to the garage then likely all the plugs (including the garage door opener) are likely on that circuit. Your idea is a good one though and it would absolutely work if there was nothing else on the circuit. Even if there was say two plugs on the circuit, but you did not need them for anything other than charging the car, you could disable one outlet and convert the other to 240v. This would slightly more than double your charge speed.

Now it likely would not be code compliant just because you would not have the required # of plugs in the garage, but it would not be a safety hazard.

Though you probably would not have any lights either?

I still want to know how the wire gets to the garage from the house. If you were lucky you may be able to pull additional conductors into that conduit. Or maybe there are already more than one circuit worth of conductors in there? Could be two "hots" and one shared neutral, which would give you two circuits.

 

[jamnmon66]

Finley&OtisDad...

Just my opinion so take it FWIW, but I think you'll be happier if you just budget to have some type of a 240v circuit installed by an electrician. At least consider getting a quote or two before you make up your mind. Tax rebates & fuel savings aside, this is a $50K car. Obviously, your financial situation is none of my business, but the fact that you can afford it implies that you're not struggling financially. I just budgeted/justified it as part of the cost of the car. As I mentioned above, I went ahead and had a HPWC installed and I'm very happy about it. There's no stress about charging speed or safety issues caused by my lack of electrical knowledge. And it's extremely convenient.

 

[Finley&OtisDad]

Finley&OtisDad...

Just my opinion so take it FWIW, but I think you'll be happier if you just budget to have some type of a 240v circuit installed by an electrician. At least consider getting a quote or two before you make up your mind. Tax rebates & fuel savings aside, this is a $50K car. Obviously, your financial situation is none of my business, but the fact that you can afford it implies that you're not struggling financially. I just budgeted/justified it as part of the cost of the car. As I mentioned above, I went ahead and had a HPWC installed and I'm very happy about it. There's no stress about charging speed or safety issues caused by my lack of electrical knowledge. And it's extremely convenient.

This is a very fair point!

 

[Glamisduner]

You could always get a JuiceBox, Durastation, or other EVSE that allows you to configure the amperage. Then use it at 16a or 24a now and use it at 40a later when you get a car and circuit that can support it.

This is where things get difficult to decide.

Decision making is circular here. Maybe you can can help!

You mean I could use the juicebox with a 14-30 adapter?
That's an option, but the tesla wall charger is cheaper and could charge faster. Of course this does not help me at all with charging my car right now unless I add a $250 tesla tap... (the same price as just buying the EVSE for the volt hah!)
Model S/X/3 Wall Connector
Is there a benefit to the juicebox over the tesla wall connector?

Option 1.
If I get a cheap volt 16amp EVSE for a NEMA 14-30 outlet for about $250 for now. Plus I will be get a tesla EVSE (32amp) when I get the model 3.
In this case the 16amp EVSE goes in the model3's trunk and I can use an adapter with it to charge the model3 with it. Or maybe I can sell it with the volt later.
I could use the standard tesla EVSE on the NEMA 14-30 with an adapter (24amps), or have a 14-50 installed (get 32 amp charging) not bad?
pros: only $250 for the EVSE now, ok spare trunk charger. Can charge model 3 at 24 amps without additonal cost!
cons: max charging will be 32 amps if I put in a 14-50 outlet for about $600-700. (I could probably live with this). Trunk charger won't be ideal but probably good enough?

Option2
Get the Juice box now, and an adapter to use a 14-30 outlet, it can charge my volt at 16 amps now or the tesla at 24 amps later Cost is around $620. I could later get get a 14-50 instealled and charge the tesla at 40 amps with an adapter. The standard model3 EVSE could go in the tesla trunk.
pros: Juicebox will charge the model 3 faster than standard EVSE it comes with, and I can use it to charge the volt at 16 amps now. Standard tesla EVSE is a good portable/backup EVSE.
cons: price $620+, is the most expensive option up front, and still limited to 40 amps. For $750 (not too much more) I could get the volt EVSE AND buy the tesla wall unit that would allow me to charge at 48 amps and I would have 3 EVSE's!

Option3
Buy 16 amp volt EVSE now $250, AND buy the tesla wall charger later $500.
pros: Fastest charging rates. I could still charge at 24 amps using standard EVSE until I decide to buy the tesla wall charger and pay for the install.
cons: don't need 3 EVSE's but maybe I could sell the volt EVSE.

Options 1 and 3 are similar, the difference is getting a 14-50 installed and using standard tesla EVSE, or just going straight for a tesla wall charger.

Right now I'm leaning towards getting the cheaper EVSE, and seeing how the model 3 does at 32 amps. I'm thinking I will have the guy run wire for a 60 amp circuit, when he installs the 14-50 in case I decide 32 amp charging isn't fast enough?

 

[davewill]

If that's your strategy the go with #1 right now, and try the UMC with the 14-30 adapter for a while once the M3 comes. If you don't like it, THEN spring for the electrical work and a wall connector. I don't think you can upgrade above 48a charging after the car is ordered, so no need to go over 60a.

The JuiceBox has connectivity and other cool features, but it appears you're more interested in price.

P.S. Spend only $238 on the 16a EVSE. That price includes one adapter, choose the "A" adapter (fits all 14-xx outlets):
Go Cable™ is THE 20 amp J1772 portable charging solution!

 

[Glamisduner]

If that's your strategy the go with #1 right now, and try the UMC with the 14-30 adapter for a while once the M3 comes. If you don't like it, THEN spring for the electrical work and a wall connector. I don't think you can upgrade above 48a charging after the car is ordered, so no need to go over 60a.

The JuiceBox has connectivity and other cool features, but it appears you're more interested in price.

P.S. Spend only $238 on the 16a EVSE. That price includes one adapter, choose the "A" adapter (fits all 14-xx outlets):
Go Cable™ is THE 20 amp J1772 portable charging solution!

If I stick with 24amp charging I'll have to get that Dryer Buddy someone linked to and ditch the other outlet.

Yea I have seen the Chinese ones even cheaper too. I was going to get this unit though, since it's circuitry is supposedly made by ClipperCreek and it's only a little more expensive.
https://www.amazon.com/AmazingE-Portable-Electric-Equipment-Connector/dp/B06XSLYDLH

I believe you can set charge times from the car in the modle 3? The car should cover most of the features the juicebox would provide? For the volt, I'm not on TOU anyways so anything should work

edit: Just canceled my order. A thought just occurred to me that the ground might not be connected to anything. If the original plug was 3 wires, and the guy split that connection to to the 2 240v outlets, then the ground may not actually be connected to anything.

 

[Glamisduner]

Ok so I am at home and I want to test my outlet. I'm getting 55 between one hot and ground and a little over 60 between the other hot and ground wire. I get about 120v between either hot and neutral and 240 volts between the two hot wires.

Since I do see voltage between hot and ground does this mean my ground is working?

The EVSE I am planning to order will not operate if it does not have a proper ground.

I am worried that the original wiring (paper covered romex) may not have had a ground like most of the house) but the outlet I'm looking at has modern romex so I figure it may have been split off the original wiring and the ground left unconnected. But getting different voltages means to me that the ground and neutral are not rigged together so it might be setup ok?

 

[eprosenx]

Ok so I am at home and I want to test my outlet. I'm getting 55 between one hot and ground and a little over 60 between the other hot and ground wire. I get about 120v between either hot and neutral and 240 volts between the two hot wires.

Since I do see voltage between hot and ground does this mean my ground is working?

The EVSE I am planning to order will not operate if it does not have a proper ground.

I am worried that the original wiring (paper covered romex) may not have had a ground like most of the house) but the outlet I'm looking at has modern romex so I figure it may have been split off the original wiring and the ground left unconnected. But getting different voltages means to me that the ground and neutral are not rigged together so it might be setup ok?

What "ground" are you testing to? Your outlets don't have a ground plug right?

You should see 240v from hot to hot, 120v from hot to neutral, 120v from the other hot to neutral, 120v from hot to ground, and 120v from the other hot to ground. Oh, and 0v from neutral to ground of course. ;-)

It sounds like whatever "ground" you were testing to does NOT have a solid connection back to your panel. :-(

Ground and neutral are supposed to be connected together but only at precisely *one* location. That is at your main service entry panel. You will notice that the ground and neutral busses are connected together in that panel (and used interchangeably). In all other places they are kept separate and neutral is an insulated conductor. So in sub-panels you need four wires from the main panel to feed the subpanel and the neutral and ground bus bars are isolated from each other.

You are likely correct in thinking that the old plug with the old wiring may not have had a ground, but then someone added the new plug off of that with modern romex, but the ground wire is not hooked to anything. I am assuming you could research this further by removing the other plug and carefully examining the other box? Though of course touching old wiring is always scary since the insulation could fall apart in your hands, etc... or get disturbed in such a way that created a hazard. ;-)

 

[davewill]

If I stick with 24amp charging I'll have to get that Dryer Buddy someone linked to and ditch the other outlet.

Yea I have seen the Chinese ones even cheaper too. I was going to get this unit though, since it's circuitry is supposedly made by ClipperCreek and it's only a little more expensive.
https://www.amazon.com/AmazingE-Portable-Electric-Equipment-Connector/dp/B06XSLYDLH

I believe you can set charge times from the car in the modle 3? The car should cover most of the features the juicebox would provide? For the volt, I'm not on TOU anyways so anything should work

edit: Just canceled my order. A thought just occurred to me that the ground might not be connected to anything. If the original plug was 3 wires, and the guy split that connection to to the 2 240v outlets, then the ground may not actually be connected to anything.

The AmazingE is a good choice and UL listed to boot. Why would the split into two outlets cause any issues with the ground/neutral? Anyway, it should be easy enough to take the covers off and see how they are wired. Also, if you're getting a dryer buddy, then just remove the second outlet altogether since it really shouldn't be there anyway.

Edit: Just saw your other post. You need to get those outlets sorted by someone who knows what they are doing. Whether you use them for EV charging or not. If that's not you, then pay an electrician to do it.

 

[Glamisduner]

What "ground" are you testing to? Your outlets don't have a ground plug right?

You should see 240v from hot to hot, 120v from hot to neutral, 120v from the other hot to neutral, 120v from hot to ground, and 120v from the other hot to ground. Oh, and 0v from neutral to ground of course. ;-)

It sounds like whatever "ground" you were testing to does NOT have a solid connection back to your panel. :-(

Ground and neutral are supposed to be connected together but only at precisely *one* location. That is at your main service entry panel. You will notice that the ground and neutral busses are connected together in that panel (and used interchangeably). In all other places they are kept separate and neutral is an insulated conductor. So in sub-panels you need four wires from the main panel to feed the subpanel and the neutral and ground bus bars are isolated from each other.

You are likely correct in thinking that the old plug with the old wiring may not have had a ground, but then someone added the new plug off of that with modern romex, but the ground wire is not hooked to anything. I am assuming you could research this further by removing the other plug and carefully examining the other box? Though of course touching old wiring is always scary since the insulation could fall apart in your hands, etc... or get disturbed in such a way that created a hazard. ;-)

I'll try to remove the cover from the other outlet before bed. But even if it's modern romex I won't know whats going on behind the wall. Perhaps the whole circuit is newer than the rest of the house, but I don't know and I don't want to rip off the drywall unless I have to.

Connecting red-black = 240v
black to neutral 118v (I think red to neutral was about 120v too)
black to ground = 70v?
red to ground = 56v?

ground to neutral = 25ohms (I would think this would indicate it's grounded at the breaker but not sure if this is too high or not).

I'm not sure

 

[eprosenx]

I'll try to remove the cover from the other outlet before bed. But even if it's modern romex I won't know whats going on behind the wall. Perhaps the whole circuit is newer than the rest of the house, but I don't know and I don't want to rip off the drywall unless I have to.

Connecting red-black = 240v
black to neutral 118v (I think red to neutral was about 120v too)
black to ground = 70v?
red to ground = 56v?

ground to neutral = 25ohms (I would think this would indicate it's grounded at the breaker but not sure if this is too high or not).

I'm not sure

From what you are describing I think that ground is likely "floating". i.e. not tied to anything. That is not good!

25 ohms is a LOT of resistance from neutral to ground. They should be solidly connected with a pretty low resistance.

My multimeter is an "electricians" meter and so it has a mode called "low-z" which allows my meter to bleed off voltage that shows up due to inductive coupling of conductors in close proximity that are not connected to anything. I suspect you are seeing "ghost voltage" on a "floating" conductor (i.e. not attached to anything)

 

[Glamisduner]

From what you are describing I think that ground is likely "floating". i.e. not tied to anything. That is not good!

25 ohms is a LOT of resistance from neutral to ground. They should be solidly connected with a pretty low resistance.

My multimeter is an "electricians" meter and so it has a mode called "low-z" which allows my meter to bleed off voltage that shows up due to inductive coupling of conductors in close proximity that are not connected to anything. I suspect you are seeing "ghost voltage" on a "floating" conductor (i.e. not attached to anything)

Ok I forgot I'm supposed to shut the power off for that line when measuring ground. Once the power was off I got an infinite reading so the ground is not connected to the neutral

I verified this by removing the other 240v out's cover. The second outlet is simply chained to the first one. and the round wire was attached to nothing.

The interesting news is that the old paper wire does in fact have 4 wires including ground. I traced and verified the run that goes into the first box, there's a tear in the insulation near the roof and I counted 4 wires. This means somewhere behind the drywall (probably right above the first box where the wires enter there is a ground wire. I verified .4 - .6 ohms of resistance between neutral and this wire (which is basically nothing considering its just higher than the reading I get when touching the Fluke multimeter's leads together).

Looks like I should either buy the Chinese EVSE that does not require a ground, or cut into / remove the dry wall to find the ground. The drywall was never finished so I can see all of the screws... Maybe I can just remove it then put it back

 

[eprosenx]

Ok I forgot I'm supposed to shut the power off for that line when measuring ground. Once the power was off I got an infinite reading so the ground is not connected to the neutral

I verified this by removing the other 240v out's cover. The second outlet is simply chained to the first one. and the round wire was attached to nothing.

The interesting news is that the old paper wire does in fact have 4 wires including ground. I traced and verified the run that goes into the first box, there's a tear in the insulation near the roof and I counted 4 wires. This means somewhere behind the drywall (probably right above the first box where the wires enter there is a ground wire. I verified .4 - .6 ohms of resistance between neutral and this wire (which is basically nothing considering its just higher than the reading I get when touching the Fluke multimeter's leads together).

Looks like I should either buy the Chinese EVSE that does not require a ground, or cut into / remove the dry wall to find the ground. The drywall was never finished so I can see all of the screws... Maybe I can just remove it then put it back

That is interesting news that the wire does have a ground! I would remove my electrical panel cover and verify what it looks like coming into the panel and that the ground is properly attached there, etc... (note that I recommend all proper safety precautions when doing this)

I should also call out that if the wire is "damaged" or just really old and with questionable insulation, I might think twice about using that for EV charging. EV's put many hours of full load stress on wires every single day of use. It is a lot of cycles on the wire. (so just be careful and seek professional advice if there is any question) I would want to be as sure as possible that there were no intermediate splice locations or anything that could have questionable wire nuts, etc...

Also, make sure to be 100% positive that the wire is copper and not aluminum. ;-) Small gauge aluminum conductors were a recipe for house fires.

 

[Glamisduner]

That is interesting news that the wire does have a ground! I would remove my electrical panel cover and verify what it looks like coming into the panel and that the ground is properly attached there, etc... (note that I recommend all proper safety precautions when doing this)

I should also call out that if the wire is "damaged" or just really old and with questionable insulation, I might think twice about using that for EV charging. EV's put many hours of full load stress on wires every single day of use. It is a lot of cycles on the wire. (so just be careful and seek professional advice if there is any question) I would want to be as sure as possible that there were no intermediate splice locations or anything that could have questionable wire nuts, etc...

Also, make sure to be 100% positive that the wire is copper and not aluminum. ;-) Small gauge aluminum conductors were a recipe for house fires.

Well the old romex ground has to be connected at the box because the ground only had a .5ish ohm resistance with the neutral wire (yep turning off power to measure grounds made all the difference).

I did the only sane thing one can do late monday night before going to work the next day. I removed the drywall. (I don't want to wonder all day!)

I found the ground tucked away right above the box, but to throw another wrench into the mix, the ground wire is smaller than 10AWG wires in the old romex, it's probably something like 14awg. So I don't know if this is safe to use. I read somewhere that it's safe enough to conduct current while the breaker trips most of the time. It's when you get a hot ground and the breaker does not trip that can cause issues. I guess this was pretty common back in the day?

I'm thinking to go with it, I mean the options are to use this ground, which isn't ideal, or get a charger that does not require a ground at all (which can't really be any better). I still think it's ok to upgrade the breaker to a 30 amp, but I may just leave it as a 20 at this point. I'm only talking about 16 amp chargers for now. I think I will get a new 14-50 plug for the model 3 if I can. The issue is the wire will need to be run through the same conduit that is marked "solar" in order to do it in an affordable fashion. Otherwise I may be looking at closer to $2k due to limited attic access. Or do it myself....

Anyone know a trick to fix this outlet? It's recessed too far...

 

[Rocky_H]

but to throw another wrench into the mix, the ground wire is smaller than 10AWG wires in the old romex, it's probably something like 14awg. So I don't know if this is safe to use. I read somewhere that it's safe enough to conduct current while the breaker trips most of the time. It's when you get a hot ground and the breaker does not trip that can cause issues. I guess this was pretty common back in the day?

The ground wire being smaller than all the others is actually normal even for current code. If you buy romex cable now, whenever you specify the gauge of the wire, that will only be for the hots and neutral. The ground wire is always smaller because the intent of it is that it never carries current, so it doesn't need to be thick.

 

[davewill]

For starters, ALL EVSEs require a ground and none of them require a neutral. The 10-30 adapters simply treat the neutral as a ground by relying on the assumption that this is the only outlet on the circuit and therefore there will be no current through the neutral wire...an assumption that your second outlet breaks, BTW. That smaller ground wire is entirely normal as Rocky_H pointed out.

If it were me, I would do the following:

1. Insulate that bare spot on you found in the attic.

2. Remove the second outlet. It is accomplishing nothing for you.

3. Upgrade to the 30a breaker, and install a new 14-30 outlet. -- OR -- *If you really don't want to change the breaker, replace the 10-30 with a 6-20 or L6-20, using the ground wire for ground and capping off the white wire.

Have an electrician do it, if you are not 100% confident. It should be a really cheap job, just an hour of their time. If you ask for another quote for the big job at the same time, they might just do it for you.

*Edit: I just realized that it looks like you are actually using this circuit for a dryer. In that case you'll also have to install a new 14-30 pigtail on your dryer, a simple job. It also makes the 6-20 a non-option.

The dryer buddy would be a better solution than that hacked in second outlet, so still remove it.

2nd Edit: That second outlet is recessed too far because the idiot who installed it didn't install the right kind of wall box. That one isn't meant to be used with drywall. Another reason to ditch it.

 

[Glamisduner]

Thanks guys! I was surprised how much smaller the ground wire is than the more modern romex but it does not sound like a serious issue. Sounds like all EVSE's that have 10-30 plugs are a bit hacked since 10-30's have no ground and only a neutral. Clipper units will simply not work if there is no ground, (they do not support charging off a 10-30, and will not charge off an improperly grounded 14-30).

The downside to the dryer buddy is that by the time it gets installed, I will hopefully be getting rid the volt and getting a new 14-50

I can remove the 10-30 and move the 14-30 I purchased over to it and patch the drywall later i guess, but for now this will just mean removing the dryer plug every day and swapping in the charger.

I think I will replace the 20 amp breaker, too when I have a chance. In fact I already purchased a linked 30.

I think I have a 14-30 plug for the dryer somewhere as well.

Dryer buddy is kind of expensive....

I'm thinking I should remove the metal box and replace with a plastic box (drywall has been removed so this should be easy!) Then put in this switch (or similar) https://www.amazon.com/Leviton-3033-2I-Toggle-Switch-Grounding/dp/B002E8HI56 so I can toggle between the two outlets. Total cost + some romex should be around $50.

Or get the dryer buddy. It just doubles the cost of getting a faster charger for the volt, but perhaps I wouldn't even need a 14-50 for the model 3.

 

[eprosenx]

For starters, ALL EVSEs require a ground and none of them require a neutral. The 10-30 adapters simply treat the neutral as a ground by relying on the assumption that this is the only outlet on the circuit and therefore there will be no current through the neutral wire...an assumption that your second outlet breaks, BTW. That smaller ground wire is entirely normal as Rocky_H pointed out.

If it were me, I would do the following:

1. Insulate that bare spot on you found in the attic.

2. Remove the second outlet. It is accomplishing nothing for you.

3. Upgrade to the 30a breaker, and install a new 14-30 outlet. -- OR -- *If you really don't want to change the breaker, replace the 10-30 with a 6-20 or L6-20, using the ground wire for ground and capping off the white wire.

Have an electrician do it, if you are not 100% confident. It should be a really cheap job, just an hour of their time. If you ask for another quote for the big job at the same time, they might just do it for you.

*Edit: I just realized that it looks like you are actually using this circuit for a dryer. In that case you'll also have to install a new 14-30 pigtail on your dryer, a simple job. It also makes the 6-20 a non-option.

The dryer buddy would be a better solution than that hacked in second outlet, so still remove it.

2nd Edit: That second outlet is recessed too far because the idiot who installed it didn't install the right kind of wall box. That one isn't meant to be used with drywall. Another reason to ditch it.

I agree with everything Dave said. Even if doing nothing involving your EV, switching that 10-30 receptacle to a 14-30 receptacle and replacing the pigtail on your dryer improves the safety of your dryer. Upsizing the breaker makes sense too if you are going to use this for an EV (I am not sure how your dryer is working on a 20a circuit - maybe you don't have a very powerful dryer?), but yeah, just make darned sure the wire is in good shape everywhere and 10 gauge. I am not sure how I feel about old wiring, especially when you have found at least one location of insulation damage (though the conductors in your picture look fine).

Doing some kind of transfer switch or Dryer Buddy may work well to allow sharing of the circuit for the dryer and EV. If I was going to buy a Dryer Buddy I would want the NEMA 14-30 version even if for the time being you used an adapter from 14-30 to 10-30 if you did not want to switch the pigtail on the dryer. All new dryers should be 14-30 I presume.

If it were me though, I would rather avoid the hassle of a Dryer Buddy and just run a dedicated EV circuit. ;-)

 

[CWFLY]

1 kWh from house adds 3.05 miles of battery range.

House delivered 17.98 kWh.
Car battery range increased 55 miles.


Configuration:

• 120V with extension cord (temporary). 15A circuit.
• 117V at house (measured with meter in series), 108v at car (M3 display) using UMC.

If I assume the extension cord is responsible for 'all' of the 8% voltage drop, then the 3.05 could be as high as 3.3 miles per kWh (battery indication... not actual range). My battery went from 178-233 mi. Probably not linear, but if we assume it was linear then it would take 94 kWh to fully charge a battery from 0 to 310 miles. Again, I know it's not linear, so this is a bit of a swag.

 

[eprosenx]

Thanks guys! I was surprised how much smaller the ground wire is than the more modern romex but it does not sound like a serious issue. Sounds like all EVSE's that have 10-30 plugs are a bit hacked since 10-30's have no ground and only a neutral. Clipper units will simply not work if there is no ground, (they do not support charging off a 10-30, and will not charge off an improperly grounded 14-30).

The downside to the dryer buddy is that by the time it gets installed, I will hopefully be getting rid the volt and getting a new 14-50

I can remove the 10-30 and move the 14-30 I purchased over to it and patch the drywall later i guess, but for now this will just mean removing the dryer plug every day and swapping in the charger.

I think I will replace the 20 amp breaker, too when I have a chance. In fact I already purchased a linked 30.

I think I have a 14-30 plug for the dryer somewhere as well.

Dryer buddy is kind of expensive....

I'm thinking I should remove the metal box and replace with a plastic box (drywall has been removed so this should be easy!) Then put in this switch (or similar) https://www.amazon.com/Leviton-3033-2I-Toggle-Switch-Grounding/dp/B002E8HI56 so I can toggle between the two outlets. Total cost + some romex should be around $50.

Or get the dryer buddy. It just doubles the cost of getting a faster charger for the volt, but perhaps I wouldn't even need a 14-50 for the model 3.

I am not sure why you would want to replace the metal box with a plastic one unless you need more space in the box? You just need to make sure to ground the box if you stick with the metal one. You want a box that will stand up well to the insertion force of a 14-30.

I am not suggesting this, but a Clipper Creek unit probably would work with the ground wire tied to that neutral just like the Tesla does. But I would not do it if the unit is not rated for it. Neutral and ground should be at the same potential and that is what the EVSE's are detecting is that they have known voltage potential from hots to what they think is ground. It is part of their safety system to make sure they have a functioning ground.

Just make sure you get a breaker that is listed for use in your model panel. Different manufacturer units are different. ;-)

As for the switch thing: I have no idea if using a light switch style setup would meet code, but for SURE a single pole switch like you have linked to would not. For a 240v circuit you need to switch BOTH the hots. Otherwise both plugs would always have one hot live. The unit you linked to is probably mostly used in commercial lighting where they do 277v circuits from phase to neutral. Since one side is neutral it does not need to be switched.

I am sure you can find a transfer switch though that is rated for what you need that will be cheaper than a dryer buddy.