of dust and shall have no openings (such as holes for attachment screws) through which dust could enter the enclosure.
(2) Damp or Wet Locations. In damp or wet locations, equipment enclosures, boxes, conduit bodies, and fittings shall be placed or equipped so as to prevent moisture from entering or accumulating within the enclosure, box, conduit body, or fitting. In wet locations, including normally dry or damp locations where surfaces are periodically washed or sprayed with water, boxes, conduit bodies, and fittings shall be listed for use in wet locations and equipment enclosures shall be weatherproof.
(3) Corrosive Atmosphere. Where wet dust, excessive moisture, corrosive gases or vapors, or other corrosive conditions may be present, equipment enclosures, boxes, conduit bodies, and fittings shall have corrosion resistance properties suitable for the conditions.
FPN No. I: See Table 110.20 for appropriate enclosure type designations.
FPN No. 2: Aluminum and magnetic ferrous materials may corrode in agricultural environments.
(D) Flexible Connections. Where necessary to employ flexible connections, dusttight flexible connectors, liq- uidtight flexible metal conduit, liquidtight flexible nonmetallic conduit, or flexible cord listed and identified for hard usage shall be used. All connectors and fittings used shall be listed and identified for the purpose.
(E) Physical Protection. All electrical wiring and equip ment subject to physical damage shall be protected.
(F) Separate Equipment Grounding Conductor. Where an equipment grounding conductor is installed within a lo cation falling under the scope of Article 547, it shall be a copper conductor. Where an equipment grounding conductor is installed underground, it shall be insulated or covered copper.
(G) Receptacles. All 125-volt, single-phase, 15- and 20- ampere general-purpose receptacles installed in the locations listed in (1) through (4) shall have ground- fault circuit-interrupter protection:
(1) Areas having an equipotential plane
(2) Outdoors
(3) Damp or wet locations
(4) Dirt confinement areas for livestock
GFCI protection shall not be required for an accessible receptacle supplying a dedicated load where a GFCI protected receptacle is located within 900 mm (3 ft) of the non-GFCI-protected receptacle.
547.6 Switches, Receptacles, Circuit Breakers, Control- lers, and Fuses. Switches, including pushbuttons, relays, and similar devices, receptacles, circuit breakers, controllers, and fuses, shall be provided with enclosures as specified in 547.5(C).
547.7 Motors. Motors and other rotating electrical ma- chinery shall be totally enclosed or designed so as to minimize the entrance of dust, moisture, or corrosive particles.
547.8 Luminaires. Luminaires shall comply with 547.8(A)
through (C).
(A) Minimize the Entrance of Dust. Luminaires shall be installed to minimize the entrance of dust, foreign matter, moisture, and corrosive material.
(B) Exposed to Physical Damage. Luminaires exposed to physical damage shall be protected by a suitable guard.
(C) Exposed to Water. Luminaires exposed to water from condensation, building cleansing water, or solution shall be watertight.
547.9 Electrical Supply to Building(s) or Structure(s) from a Distribution Point. A distribution point shall be permitted to supply any building or structure located on
the same premises. The overhead electrical supply shall comply with 547.9(A) and (B), or with 547.9(C). The underground electrical supply shall comply with 547.9(C) and (D).