Convert NEMA 5-20 to 6-20?

[wws]

A EVSE is basically a fancy extension cord. It checks for ground faults, and tells the on-board charger that is buried in the car the max current (not voltage) the circuit can handle. It then turns power on and off at the direction of the on-board charger. This is why so many of us cringe when people (even some well-known YouTube personalities who definitely know better) call an EVSE a "charger".

NEMA plugs and receptacles include:

NEMA 5 (and TT-30): 120V only
NEMA 6: 240V only
NEMA 14 (and obsolete NEMA 10): 120/240V

When using a 14- (or 10-) series connection, EVSEs generally use the 240V portion - leaving the neutral blade unused. One certainly could use the neutral and one of the hots to bring 120V to the car. But why would you want to? You'd charge at half speed. And the on-board chargers on some non-Tesla cars even further limit 120V charging to 12 amps - regardless of what the EVSE says the max current can be.

A large RV does want both 120 and 240V. Besides splitting 120V loads between the two hots, they can also run more energy intensive things like air conditioning using 240V as needed.

 

[Rocky_H]

A large RV does want both 120 and 240V. Besides splitting 120V loads between the two hots, they can also run more energy intensive things like air conditioning using 240V as needed.

I thought that too, originally years ago, but apparently they don't. They just have a lot of 120V loads, but no 240V ones.

 

[davewill]

I thought that too, originally years ago, but apparently they don't. They just have a lot of 120V loads, but no 240V ones.

My understanding is that every once in a while, a very large RV will have 240v air conditioning, but it's not common because 240v isn't always available, and 120v is.

 

[brkaus]

My understanding is that every once in a while, a very large RV will have 240v air conditioning, but it's not common because 240v isn't always available, and 120v is.

Very uncommon to have 240v accessories in an RV. My neighbor has the biggest thing going and nothing is 240. 3 AC units, hot water, cooking, washer and dryer. All of it 120.

Surprised me too, but google searches seam to confirm.

 

[DangerRuss]

That makes sense.
The usage is different.
RV has much more complex and specific requirements. EV can and should take whatever it can get.

 

[dafish]

Sorta backwards Danger. An RV uses pretty basic power and is, in my view, electrically crude. As are some RV parks power panels. One man’s admittedly biased perspective.

here is some reading for you.

RVelectricity: So, does my RV use 120 or 240 volts?

Dear Readers, I just taught my first RVelectricity seminar in 16 months at the Airstream International Rally in Lebanon, TN. The question of whether an RV uses

www.rvtravel.com

The 50-amp 120/240-volt 3 pole 4