According to zxcvbob :

He did say in the original message that it was a 4-wire circuit (it was
a subtle reference; he said "14-30R")

Despite having written the electrical wiring FAQ, I don't keep the
plug/receptacle specs in my head. Sigh. Oops ;-)

Still bad of course ;-)
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.