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I have a (new to me) Chevy Bolt and will soon receive a Dewalt 16 amp, 240 V portable EVSE with a 6-20 plug. My in-laws live about 220 km/150 miles away, so in range without a top-up but need to charge on arriving; taking 20 hours to recharge the 66 kWh battery even if it’s pretty low is fine.

In their shop, they have a 6-50 welder outlet right near the garage-style door. That’s easy to access but would require a 6-50 to 6-20 adapter; Home Depot sells one (online) that has a 20 amp breaker built-in. They also have a 6-20 outlet (installed for a now-rarely-used table saw), but it’s in the middle of the shop and would require awkwardly stringing the 25-foot EVSE cord out a window to the driveway.

The 6-50 receptacle is on a dedicated circuit, 60 amp breaker. The 6-20 is on a dedicated circuit, 30 amp breaker. These were all installed by an electrician when the shop was built in 2005; I haven’t inspected the wires, but I’m confident they’re up to code for the time (knowing my retired in-laws and talking to them about it) and not touched since construction. In particular, the breakers would imply heavier wires than the minimum 12 gauge for the 6-20. The breakers are not GFCI as (I think) would be required for a new installation for this purpose, but I don’t think a retrofit would be required anyway.

Are there any concerns using this setup roughly once a month when we visit for weekends? Any preference for the easier-to-access 6-50 outlet with an adapter or the slightly-awkward 6-20 outlet with no adapter?

They live in WA (USA), we live in BC (Canada), if it matters. They’re in a rural area with no public DC chargers and very limited public AC chargers within a 60 minute drive.

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    Usually you want to limit the amount of connections, it is better to plug directly into a receptacle, but awkward and a possible tripping hazard, a safe UL listed adapter with a built in breaker is the better choice.
    – crip659
    Commented Apr 2 at 12:28
  • Yeah, that’s precisely my thought. In this case, the 6-50 outlet would probably be less of a trip hazard despite the extra connection because of the location of the outlet. Trying to balance which is worse. (I think both would be ok; if it were my home and never used for the welder, I’d replace the 6-50 with a 6-20 and put a 20 amp breaker on it.)
    – Alex Hill
    Commented Apr 2 at 12:59

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The adapter with the built-in 20 amp breaker from Home Depot sounds like a good option for using the 6-50 outlet. This will ensure that the EVSE operates within the appropriate current limits and provides an additional layer of safety.

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Use the 6-50 because you can count on correct breaker protection.

Funny fact about large motors. They have overload protection right on the motor, where it has a huge advantage: it knows what temperature the motor is. As such, on a motor load, the breaker is not needed for overload protection and only needs to guard against short circuits. As such, motor rules in NEC article 430 allow the breaker to be enlarged as much as 225% above motor amps and circuit amps. This helps reduce nuisance trips.

Separately, NEC article 630 grants the right to wildly oversize breakers on light duty-cycle welders. Obviously a 60A breaker on a 50A socket is nuts. So that circuit could even have as small as #12 wire depending on the facts.

The listed adapter has a breaker, as UL requires, so you're all set.

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