Wiring requirements for animal confinement buildings

The following chart is based on National Electrical Code Article 547 - Agricultural Buildings

ELECTRICAL WIRING REQUIREMENTS FOR ANIMAL CONFINEMENT BUILDINGS BASED ON NATIONAL ELECTRICAL CODE® ARTICLE 547 - AGRICULTURAL BUILDINGS
BUILDING TYPE	WIRING METHOD	LIGHT FIXTURES	BOXES, FITTINGS, CONTROLS	MOTORS	PANEL-BOARDS	EQUI-POTENTIAL PLANE See note 1
Livestock Confinement	Copper SE, UF, rigid nonmetallic conduit (RNMC) See note 4	Enclosed, listed for wet locations. Dusttight and corrosion resistant	Dusttight, watertight, and corrosion resistant	Totally enclosed fan cooled (TEFC)	Not allowed	Required
Open-sided building (no gates or doors to confine livestock)	Copper SE, UF, RNMC	General use	General use	TEFC	Not allowed	Required
Horse barn or stable	Copper SE, UF, RNMC	Enclosed over stalls, hay, or bedding. General use elsewhere. See note 2.	In bedding areas, switches and outlets must be dusttight with weatherproof covers	TEFC	General use	Required
Milking parlor	Copper SE, UF, RNMC	Listed for wet locations	Watertight and corrosion resistant	TEFC	Not allowed	Required
Dairy barn, tie stall or stanchion	Copper SE, UF, RNMC	Enclosed, listed for wet locations, corrosion resistant	Dusttight, watertight, and corrosion resistant	TEFC	Not allowed	Required
Milk room	Copper SE, UF, RNMC, and EMT with watertight fittings	Listed for wet locations	Watertight	TEFC	Raintight	Not required
Equipment room, office, or lunch room	General use See note 3	General use	General use	General use	General use	Not required
Poultry confinement	Copper SE, UF, RNMC	Dusttight, watertight, and corrosion resistant See note 5	Dusttight, watertight, and corrosion resistant	TEFC	Not allowed	Not required
Silo and feed rooms	Copper SE, UF, RNMC	Listed for damp location, corrosion resistant, dusttight	Moisture and corrosion resistant, dusttight	TEFC	Raintight	Not required
Hay or bulk feed storage	Copper SE, UF, RNMC, and EMT	Enclosed, dusttight	Dusttight	TEFC	Not allowed	Not required

Note 1. An equipotential plane is required to be installed in areas with concrete floors where electrical equipment or systems are installed. A voltage gradient ramp must be installed where livestock regularly enter and exit an area with an equipotential plane.

Note 2. Fixtures over stalls must have substantial guards where mounting does not prevent contact by horses.

Note 3. Only wiring methods approved for the location shall be installed in concealed walls and ceilings of buildings, or portions thereof, that are contiguous with or adjoin confinement areas. (Metallic-sheathed cables, or metallic or nonmetallic raceways may be acceptable) (Nonmetallic-sheathed cables are not permitted)

Note 4. Expansion fittings for rigid nonmetallic conduit (RNMC) shall be installed in accordance with NEC Section 347-9.

Note 5. Keyless gasketed lampholders with brass shells and open lamps are allowed only with special permission. Special permission must be requested and obtained in writing, in advance. Special forms must be completed and approved by the property owner, the owner's insurance company, and the department.

Except for the final service or feeder conductors extended to a building disconnecting means, aluminum conductors, boxes, fixtures, and fittings are not permitted to be installed in any portion of agricultural buildings. Motors must be installed so that dust and debris build-up will not restrict cooling. Thermostats are motor controllers and must be provided with a disconnecting means in accordance with NEC Article 430. All electrical equipment must be readily accessible. Where required, minimum working clearances must be provided. It is advisable to consult with the appropriate insurance company before proceeding with any electrical wiring installation.