Everyone has covered it well but I would also say you may have gotten one of the smarter electricians. My son got one who wired 240 to his 30 connector and luckily just blew the converter. Don't even ask me how, I know it's 3 wires. My son replaced the converter and the electrician repaired the 240 mistake but then reversed the polarity in the 30 amp connection. Things were acting crazy in his TT so I told my son how to check it he said it appears to be backwards and he questioned the electrician. The electrician insisted that the TT was wired wrong. I went to the hunt camp with my son and corrected the wiring in the panel plug and all is well. Duuuhhhh
