calamus wrote:
This is for a CAMPER, Yes there are cases where you could use a 3 wire 240 volt but I have not seen any residential wiring done other than a well (and that is rare) with 240v 3 wire they have not done it for years now.
Times and standards change but here is a short list of things I have seen, some are popular in shops but some folks have a "Home workshop" that is "Industrial strength"
Parent's house the cloths dryer was 3 wire,, I did not sell dryers but I worked in the warehouse from which they were delivered, MANY with 3 wire cords.
Grain/hay elevator was 240 volt 3 wire and 15 amp too boot
Welders
Air compressors
Other machines
And of course the well pump though it was hard wired.
All HOT-HOT-Neutral back then, No safety ground for the dryer
The other gear is hot-hot-safety ground. No neutral.
Many electricians look at that heavy duty TT-30 and what they see, is not what they are holding in their hand.. So they screw up.
This is why I installed my own.. I'm trained.. a bit differently (Electronics) and understand that same connectors can be used all over the voltage chart.
Ever been bit by 500 volts DC... (Been there)