L2 Charging: EVSE vs. 240V Charging Cable

that's the setup i have. but other than moving to a new residence, idk how many places you can plug in an L2, especially with all the plug configurations.
maybe rv parks and the like.

 

In the discussions here about using dryer plugs, I thought that that it was mentioned that standard electric dryer plugs in the US have a neutral rather than a ground, to power the 120V components in the dryer (controls, lights). But a plug for a car charger is required to have a ground. The issue is that since the neutral in a 120V circuit carries current, there typically is a voltage drop between the neutral at an outlet and where it is grounded back at the panel or wherever. Since the car chassis is connected to what is supposed to be the ground, if you use a neutral rather than a ground, there will be a voltage charge on the car chassis against ground, which is potentially dangerous to people touching the car. Thus the requirement that the charger be grounded, not "neutral"d.

 

this is where life gets complicated.

 

That is correct. Normally, that voltage drop would be so slight, no one would ever notice it. But, if the neutral loses its bond to ground, that could kill you. I got nailed hard by an unbonded neutral in Honduras. Sweaty shirt, laying on a tile floor, put wrench on bolt on refrigerator door, screamed like little girl. I got my meter and measured 70 volts from ground on the neutral on all the outlets in the house and 50 volts on the hot leg, and that fridge apparently didn't have the frame connected to ground. The house neutral had never been connected to ground and people were living in there!

I'm not recommending an ungrounded receptacle, but as I understand the system, the ground is there for safety if something goes wrong. Normally, the car's body would float electrically, just like it does when not plugged in because the HV electrical components are all isolated from it. If they become unisolated, the car throws a code for a voltage leak. The ground wire for the EVSE is an additional safety measure in case a voltage leak develops while the car is off.