> Before 1999 most dryers and kitchen ranges had the
> neutral and ground bonded at the unit so that there
> was need for only one path, the ground.
I don't have an old NEC handy to check, but I'm practically certain tying an
exposed metal chassis to neutral has been forbidden for much longer than since
1999. Doing this would mean that if the neutral becomes open for some reason,
the exposed chassis could have as much as 110vac on it, even with the appliance
turned off !
Leaving the exposed chassis not connected was permissible for a long time,
perhaps that's what was outlawed in 1999. (Although I didn't find any reference
to this changing in 1999)
> All that said most older welders
> that I have wired for use a three prong crows foot
> configuration.
Most welders, even current models, run entirely on 220v and so have no need for
a neutral. The third wire is for safety ground.
http://www.hobartwelders.com/om/0300/o303n_hob.pdf
Randall
|