what gauge wire is needed for a 240 V 30 A circuit?

[ishiyakazuo]

Thanks everyone. I really was just asking about a 30A breaker, not a 30A EVSE. I'm aware of the 20% buffer for continuous draws, and I'll set my EVSE's current limiter to 24A. I actually have a dedicated 30A breaker circuit that I can use already, but the 20A circuit with 12 gauge wire that I was asking about is in a more convenient spot. If new wire didn't need to be run, I would have just paid someone to convert it. I think I'll just stick with my less conveniently located one though. I'm in a rental place right now, so any investment over a hundred bucks or so in rewiring isn't really worth it to me.

If your EVSE has the current switches, you could set it for 16A and stick with the 12 AWG run to keep the convenient spot. If adding more charge time isn't a big deal, go for the convenience part

Actually, the Siemens (a very good unit) DOES allow you to set an internal dial for lower current, but they still require a 30A circuit.

FYI, GE's residential DuraStation's manual has a physical jumper with it, explicitly for the purpose of connecting to lower current circuits. In my case, mine is connected to a 240V 40A circuit, so no big deal, but there are EVSEs out there that explicitly say that's OK.