New Mach E owner here

[generaltso]

I would be more concerned with the wiring between outlet and (40amp ?) breaker the OP said he had serving the 10-50 outlet.

If it's a 40A circuit that was installed for an electric range, I would hope the wire was sized appropriately. I guess it's good practice to double check the wiring when repurposing any circuit.

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[Flint302]

While we debate the potential of burning down your house....welcome aboard and enjoy the ride.

 

[crl]

While we debate the potential of burning down your house....welcome aboard and enjoy the ride.

HA! Yes the more I read the less confident I am in using this circuit temporarily. But yeah, if it's good enough for a 2 year old electric range, it should be able to handle a 32a load. I'll find out later today....if you see smoke then you'll know.

 

[generaltso]

HA! Yes the more I read the less confident I am in using this circuit temporarily. But yeah, if it's good enough for a 2 year old electric range, it should be able to handle a 32a load. I'll find out later today....if you see smoke then you'll know.

I just noticed you're in VT. Welcome! There aren't many of us.

 

[dtbaker61]

HA! Yes the more I read the less confident I am in using this circuit temporarily. But yeah, if it's good enough for a 2 year old electric range, it should be able to handle a 32a load. I'll find out later today....if you see smoke then you'll know.

the thing we are most concerned about is the wire size because EV charging can pull continuous current for more than 3 hours. House wiring code and outlet ratings are commonly sized using <3hr continuous use charts.

your outlet might handle 50amps non-continuous, but 32 'safely' for 3+hours under normal conditions. If your circuit breaker is 40a, then the wiring in the wall might be one size smaller.... able to carry max of 40amp non-continuous, but right on the edge at 32amps for continuous use.

A 50amp outlet, whether it is 10-50 or 14-50, *should* have 6awg copper conductors.... and can safely support 32amp continuous use like an EV charging for 3+ hours

....so you might want to pull the cover off the outlet, or electrical panel so you can see the wires running to the outlet, take a picture and/or measure and/or look at the insulation closely to see if you see a size printed on the insulation.... hopefully 6awg

 

[Maquis]

Are you sure? I know a 6-50 has a ground with no neutral, but I think a 10-50 has a neutral and no ground. If the receptacle is fed off a main panel, the ground and neutral are probably bonded together anyway, but the adapter probably doesn't connect the neutral to the ground pin, so it would fault.

Worst case, it would be pretty easy to replace the 10-50 outlet with a 6-50 outlet.

Technically, you are correct, but if the circuit originates in the main panel, the neutral connects to the same place as a ground would. An EVSE will have no problem with it.

If it’s coming from a subpanel, the wire that is currently serving as the neutral should be moved from the neutral to the ground bus and re-identified, in which case, I’d replace it with a 6-50.

 

[crl]

I just noticed you're in VT. Welcome! There aren't many of us.

Thanks! I've only actually seen one on the road once or twice.

 

[Maquis]

the thing we are most concerned about is the wire size because EV charging can pull continuous current for more than 3 hours. House wiring code and outlet ratings are commonly sized using <3hr continuous use charts.

your outlet might handle 50amps non-continuous, but 32 'safely' for 3+hours under normal conditions. If your circuit breaker is 40a, then the wiring in the wall might be one size smaller.... able to carry max of 40amp non-continuous, but right on the edge at 32amps for continuous use.

A 50amp outlet, whether it is 10-50 or 14-50, *should* have 6awg copper conductors.... and can safely support 32amp continuous use like an EV charging for 3+ hours

....so you might want to pull the cover off the outlet, or electrical panel so you can see the wires running to the outlet, take a picture and/or measure and/or look at the insulation closely to see if you see a size printed on the insulation.... hopefully 6awg

8 AWG is perfectly adequate for a 40A circuit. There’s virtually no chance #6 was run from a 40A breaker to power a range.

That said, EV charging is continuous and a marginally installed circuit that has powered a range for years without issues might have issues powering an EVSE. A thorough inspection by a qualified electrician is a good idea.

 

[generaltso]

An EVSE will have no problem with it.

Wouldn't that depend on the adapter? If the adapter maps the neutral pin of the 10-50 outlet to the ground pin of the 14-50, I agree it will work. But if it just passes the neutral through to the neutral pin of the 14-50 and leaves the ground pin open, I would think the EVSE would fault.

 

[Maquis]

Wouldn't that depend on the adapter? If the adapter maps the neutral pin of the 10-50 outlet to the ground pin of the 14-50, I agree it will work. But if it just passes the neutral through to the neutral pin of the 14-50 and leaves the ground pin open, I would think the EVSE would fault.

Good point! The good news is that if the ground pin is open, the EVSE will throw a fault - it won’t fry anything or anybody.

 

[generaltso]

Good point! The good news is that if the ground pin is open, the EVSE will throw a fault - it won’t fry anything or anybody.

Right. And if it does fault, I think rewiring the outlet to a 6-50 would be an easy fix (but would require a different adapter).

 

[Maquis]

Right. And if it does fault, I think rewiring the outlet to a 6-50 would be an easy fix (but would require a different adapter).

The ones on Amazon are sold for EV use and the customer reviews say they work. My guess is that they connect both the ground and neutral on the 14-50 to the neutral on the 10-50. If the neutral was left open and somebody used it to power their RV, it would be a disaster. Of course, they’re made in China and not UL listed.

 

[crl]

Right. And if it does fault, I think rewiring the outlet to a 6-50 would be an easy fix (but would require a different adapter).

Worst comes to worst if the adapter doesn't work I can always head up the road to gmp's office on a saturday and plug it in for free so I am not sol. I was just thinking a temporary adapter connection might work out (I don't cook anyway so who needs the stove).

FWIW this is the adapter I settled on as it looked to be up to the task:
https://www.amazon.com/dp/B0BBR8L8X1

 

[generaltso]

The ones on Amazon are sold for EV use and the customer reviews say they work. My guess is that they connect both the ground and neutral on the 14-50 to the neutral on the 10-50. If the neutral was left open and somebody used it to power their RV, it would be a disaster. Of course, they’re made in China and not UL listed.

Yeah, it makes sense that an adapter specifically designed for EV use would wire the neutral to the ground. But that could also cause issues if the outlet was fed from a sub-panel.

 

[crl]

Yeah, it makes sense that an adapter specifically designed for EV use would wire the neutral to the ground. But that could also cause issues if the outlet was fed from a sub-panel.

No sub panels.

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