4wire dryer connections

[kwired]

I think I understand your statement but don't most code changes come about to make electrical installations safer and somewhat idiot proof, with regards to personal injury?

This code change was long overdue when it happened. We are (were) supposed to separate grounded and equipment grounding conductors beyond service equipment or first disconnect of separately derived systems for years - except for ranges and clothes dryers. Most of the time there is not much safety risk doing that but when things fail is when you have the bigger problems. Also use of a grounded conductor that carries current in normal use does result in a rise in voltage to other grounded objects because of voltage drop on that grounded conductor, the more current the grounded conductor is carrying plus the longer the circuit length the more voltage drop will be present.

When I was a kid we had an old range in the basement my mother used for canning fruits and vegetables. If you stood on the concrete floor (3 wire cord - that was standard then unless it was a mobile home).

If you stood barefoot on concrete floor and touched that range even when it was not in use - you often got shocked. I wasn't all that knowledgeable about electricity then was maybe only 10 years old at that time, but my best guess was it was mostly voltage drop on the grounded conductor and no malfunction of anything.