Taken from the 1996 National Electrical Code or NEC for short.
The NEC is adopted in all 50 states.
ARTICLE 551--- - RECREATIONAL VEHICLES, PARKS 70-667
551.81 Receptacles. A receptacle to supply electric power
to a recreational vehicle shall be one of the configurations shown in figure 551-46(c) in the following ratings:
(a) 50-Ampere. 125/250-volt, 50-ampere, 3-pole, 4-wire
grounding type for 120/240-volt systems
(b) 30-ampere - 125-volt, 30-ampere, 2-pole, 3-wire
grounding type for 120-volt systems
(c) 20-ampere - 125-volt, 20-ampere, 2-pole, 3-wire
grounding type for 120-volt systems
(FPN) Complete details of these configurations can be found in National Electrical Manufactures Association Standard for dimension of Attachment Plugs and Receptacles, ANSI/NEMA WD 6-1989, Figures 14-50, TT, and 5-20.
So, what does this mean? It means NEMA never had a 120-volt configuration for the 14-50 since 1989 when it was adopted and must be wired as intended. There is no “grandfathered in” clause for miswiring the NEMA standard.
Having worked a few years for an attorney in expert witness testimony, believe me, a RV park could get sued doing this. The question is, would it be profitable?
