Doublewide Environment

[czars]

I have a client that is installing a new range to replace her cooktop in her doublewide. The new range requires a 50A circuit. I will have to install a new circuit (cable) under the doublewide. I plan to support the cable, off the ground, near the underside of the floor using tie wraps. Would the underside environment of the doublewide be considered a "dry" environment which would permit me to use NM-B cable.

 

[iwire]

I think NM is a no go.

550.15 Wiring Methods and Materials. Except as specifically
limited in this section, the wiring methods and materials
included in this Code shall be used in mobile homes. Aluminum
conductors, aluminum alloy conductors, and aluminum
core conductors such as copper-clad aluminum shall not be
acceptable for use as branch-circuit wiring.

(H) Under-Chassis Wiring (Exposed to Weather). Where
outdoor or under-chassis line-voltage (120 volts, nominal,
or higher) wiring is exposed to moisture or physical damage,
it shall be protected by rigid metal conduit or intermediate
metal conduit, except as provided in (1) or (2). The
conductors shall be suitable for wet locations.

(1) Where closely routed against frames and equipment
enclosures, reinforced thermosetting resin conduit
(RTRC) listed for aboveground use, Type MI cable,
electrical metallic tubing, or rigid polyvinyl chloride
conduit (PVC) shall be permitted.

(2) Where extending vertically from a direct-burial depth
of at least 457 mm (18 in.) below grade and terminated
to a factory-installed conduit or enclosure, Schedule 80
PVC or RTRC listed for exposure to physical damage.