l6sman wrote: ↑
Sun Dec 27, 2020 9:03 am
There is no way to tell the Leaf to only charge at 24 amps instead of 30 amps is there?
Of course there is. So long as you have a sufficiently sophisticated charging station. The maximum charge rate is set in the handshake between the EVSE and the OBC, but to know that, the EVSE needs to know what to tell the OBC.
On some units, that's done with a front panel switch. Or a smartphone app. On a Grizzl-E (which is what I have), it's done with an internal DIP switch, which the nice people at United Chargers Canada will be happy to do for you, before they ship it.
And the general rule of thumb is to avoid continuous loads of more than 80% of a circuit's rated capacity. And never, ever, replace a breaker with a higher rated one unless the wires are actually heavy enough to handle the higher current.
As to the original question, on all current 4-wire single-phase 240V sockets, at least in the U.S. (and probably Canada), two lines are hot, the third is neutral, and the fourth is safety ground, while on all current 3-wire single-phase 240V sockets, it's two hots and a safety ground. There are obsolete 240V single-phase sockets that were used for electric clothes dryers back in the 1960s, with two hots and a neutral (if you wanted a safety ground, you presumably bonded the frame of the dryer to a cold water pipe). A Grizzl-E doesn't need a neutral, as everything runs on 240VAC, but it can be bought with either a 3-wire or 4-wire plug; if you buy it with a 4-wire plug, the neutral doesn't actually connect to anything inside the case.