wrote:
What's the story with the 4-prong plugs? What is the purpose of the
fourth prong?

Up until a few years ago dryers and ranges exploited an exception in
the National Electrical Code, dating from WWII that allowed them to
share neutral and ground on one wire, to save copper for the war
effort.
Phil Simmonds finally got a proposal through to remove that exception.
He actually said "the war is over". You can still do it in a
grandfathered installation but all new installations require 4 wires.


Interesting. So if I were to get a new drier with a four-prong
connector, would I be required to run a new 4-wire electrical line to
the breaker panel? Or does it only apply when installing a new
electrical line?

Art Harris