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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.

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