Elmo wrote:

I think someone said it doesn't really matter if it's on a sub panel anyway
because the white wire is physically wired as a ground in the main panel
and in the sub panels, not as a neutral.

The branch circuit has to originate at the service (250.140). I believe
that has always been the requirement. If it goes to a subpanel, it
violated the NEC when installed.

At a subpanel, if you are connecting a drier and connect the white wire
to "ground" you are putting current on the ground wires. Among the
problems is if the ground back to the source fails this could make all
the downstream grounds hot. If you connect to the neutral bar, if there
is a problem with the supply neutral the drier frame could be way above
ground potential.

IMHO you should at least determine what the major breakers feed and
label them.

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bud--