On the 14-50 receptacle, is the round connector neutral?

I learned something today, never assume and past teachings can cloud those assumptions. I stayed at the Montage resort in Laguna Beach this week. A place where some arrive driving a Lamborghini and their luggage arrives in a Rolls Royce Phantom. I took my RAV4 EV and knew they didn’t have a charging station but they did have a 220 volt 14-50 outlet where I could charge my car. My EVSE has a three prong 6-50 plug and I had made an adapter to charge from their 14-50 outlet. I assumed on the 14-50 plug (RV type plug with four connectors) that the center blade was the neutral and round connector was the ground. I found out the round connector is the neutral and center blade is not used. I got a fault light on my EVSE and the car didn’t charge. When I drove home I had enough charge left to make the 57 miles without a problem. I rewired my adapter for next time I run into a 14-50 receptacle.

Since you made an adapter to from NEMA 14-50 to NEMA 6-50, the Neutral doesn't matter because the 6-50 doesn't include it. Most likely, their outlet was not properly grounded. As you can see here, taken from Wikipedia, the rounded pin on both the 14-50 and the 6-50 are supposed to be ground.

Sounds like they have a 3-wire circuit originally wired for an ungrounded 10-50 outlet, and they "updated" it by slapping on a 14-50 receptacle with the ground slot not connected to anything. Your connecting ground to neutral got the EVSE to pass the ground check, because neutral lines and ground lines are tied together at the supply panel. However, I think leaving your adapter wired that way would be considered generally unsafe, as you shouldn't be connecting ground to neutral lines that can carry current.

So your original assumption was correct; you should put your adapter back as it was, and you should also contact the Montage about their unsafe outlet. If my assumption is correct, then what they've done is equivalent to "fixing" your home's old 2 prong 120 outlets by sticking ungrounded 3-prong outlets in their place, which I think just about everyone would agree is not a good idea, especially for an outdoor outlet. :shock:

Mods - you should probably consider changing the title of the thread (rephrase it as a question perhaps?) as it's stating a falsehood as fact.

sobayimage said:

I assumed on the 14-50 plug (RV type plug with four connectors) that the center blade was the neutral and round connector was the ground. I found out the round connector is the neutral and center blade is not used... I rewired my adapter for next time I run into a 14-50 receptacle.

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Obviously, the wiring at the hotel was backwards. I would call them and let them know.

You were originally correct... Round is ground, center blade neutral (and not needed for your 240 volt EVSE) and the two 120 volt power pins / blades.

I leave that center neutral blade off my adaptors... it's easier to plug in, and I'm not using 120 volts, which is why the neutral is there.

TonyWilliams said:

I leave that center neutral blade off my adaptors... it's easier to plug in, and I'm not using 120 volts, which is why the neutral is there.

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Also, if you leave the neutral out, the connector will work with a 14-30, 14-50 or 14-60. I have never seen a 14-60, just the picture on the NEMA chart.

pchilds said:

TonyWilliams said:

I leave that center neutral blade off my adaptors... it's easier to plug in, and I'm not using 120 volts, which is why the neutral is there.

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Also, if you leave the neutral out, the connector will work with a 14-30, 14-50 or 14-60. I have never seen a 14-60, just the picture on the NEMA chart.

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OP's situation is actually an argument for having the neutral blade (or at least to keep it with you if it's the removable type.) If you come across a 14-50r that's improperly grounded and causes your EVSE to balk, you could "fool" it by temporarily rewiring your 14-50p to connect ground to neutral.

I would only do this if I was desperate for a charge and had no other alternative, AND I could verify that the outlet was on a standalone circuit with nothing else on it that might be passing current on neutral, and I'd be sure to rewire my 14-50p correctly soon after. Again, connecting ground to neutral should generally be considered unsafe, however. Although Ingineer over in the Leaf forum has shown a way to safely bond ground to neutral by incorporating resistors (very useful when charging off a generator), which anyone who expects to do this frequently should study.

The reason I thought I had wired the neutral/ground wrongly was that I have a 14-50 (RV plug) to 10-30 (old dryer plug) adapter (from EVSEadapters.com) and it uses the ground connector as the neutral on the 14-50 end. Are they wrong too? I think the Montage Resort has their 14-50 receptacle wired properly because I read a blog by a Tesla owner and she had successfully charged her car there in September.

sobayimage said:

The reason I thought I had wired the neutral/ground wrongly was that I have a 14-50 (RV plug) to 10-30 (old dryer plug) adapter (from EVSEadapters.com) and it uses the ground connector as the neutral on the 14-50 end. Are they wrong too? I think the Montage Resort has their 14-50 receptacle wired properly because I read a blog by a Tesla owner and she had successfully charged her car there in September.

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10-30 plugs don't have a ground, so you have no option but to use the neutral as a ground in that case, but the same safety warnings apply. This is also why the EVSEadapters page says "Caution: For electric vehicle charging only! Not suitable for use with other appliances."

As I said before, connecting your EVSE's ground to the neutral pin will work to get the EVSE to pass its ground check, but by no means does that imply the 14-50 receptacle is then wired properly. If connecting your EVSE's ground to the 14-50's ground (round pin) doesn't work, then it does mean that their receptable is wired improperly.

@fooljoe +1

IMHO, a 14-50 socket for EV Charging that is connected to a circuit that does not have a neutral should leave the neutral pin open. The ground pin should never be open and should only be connected to neutral in an emergency. A 208/240V EVSE puts all the load on the L1/L2 pins, not the neutral (if even present) or ground.