It makes no difference-there's no such thing as upside down. I never met an electrical inspector that cared either way-just as long as they were wired correctly and worked.
Correct, most commercial electricians install ground plug up, residential ground side down
It is not addressed in the NEC (was raised and rejected)18-36 Log #3897 NEC-P18 Final Action: Reject
Submitter: Ronald Standley, E Light Electric Services
Recommendation: Add new text as follows:
Exception No. 1: Where metal cover plates are installed, receptacles shall be
mounted such that the ground pin opening is above the hot and neutral
Substantiation: If multiple failing conditions are encountered (i.e., plug not
fully inserted, metal cover loosens, etc.) it is possible that the metal cover
could contact the hot conductor creating a short circuit and a fire hazard.
Panel Meeting Action: Reject
Panel Statement: This proposal is not substantiated with incident data
indicating burn or electrocution exposure or the circumstances surrounding
Additionally, the proposal only addresses receptacles installed in a vertical
plane. How does one insure in a receptacle mounted on a horizontal surface
that the ground pin opening is above the hot and neutral openings?
Number Eligible to Vote: 11
Ballot Results: Affirmative: 11