386-Surface Metal Raceways

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I. General

of conductors or cables installed in surface metal raceway shall not be greater than the number for which the raceway is designed. Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles.
The derating factors of 310.15(B)(2)(a) shall not
apply to conductors installed in surface metal raceways
where all of the following conditions are met:

(1) The cross-sectional area of the raceway exceeds

386.1 Scope. This article covers the use, installation,

2500 mm 2
(4 in. 2).
and construction specifications for surface metal raceways and associated fittings.

386.2 Definition.

Surface Metal Raceway. A metallic raceway that is in- tended to be mounted to the surface of a structure, with associated couplings, connectors, boxes, and fittings for the installation of electrical conductors.

386.6 Listing Requirements. Surface metal raceway and associated fittings shall be listed.

II. Installation

386.10 Uses Permitted. The use of surface metal race- ways shall be permitted in the following:

(1) In dry locations.

(2) In Class I, Division 2 hazardous (classified) locations as permitted in 501.10(B)(3).

(3) Under raised floors, as permitted in 645.5(D)(2).

(4) Extension through walls and floors. Surface metal raceway shall be permitted to pass transversely through dry walls, dry partitions, and dry floors if the length passing through is unbroken. Access to the conductors shall be maintained on both sides of the wall, partition, or floor.

386.12 Uses Not Permitted. Surface metal raceways shall not be used in the following:

(1) Where subject to severe physical damage, unless otherwise approved

(2) Where the voltage is 300 volts or more between conductors, unless the metal has a thickness of not less than 1.02 mm (0.040 in.) nominal

(3) Where subject to corrosive vapors

(4) In hoistways

(5) Where concealed, except as permitted in 386.10

386.21 Size of Conductors. No conductor larger than that for which the raceway is designed shall be installed in surface metal raceway.

386.22 Number of Conductors or Cables. The number

(2) The current-carrying conductors do not exceed 30

in number.

(3) The sum of the cross-sectional areas of all contained conductors does not exceed 20 percent of the interior cross-sectional area of the surface metal raceway.

386.30 Securing and Supporting. Surface metal raceways shall be supported at intervals in accordance with the manufacturer's installation instructions.

386.56 Splices and Taps. Splices and taps shall be permitted in surface metal raceways having a removable cover that is accessible after installation. The conductors, including splices and taps, shall not fill the raceway to more than 75 percent of its area at that point. Splices and taps in surface metal raceways without removable covers shall be made only in boxes. All splices and taps shall be made by approved methods.

Taps of Type FC cable installed in surface metal race- way shall be made in accordance with 322.56(B).

386.60 Grounding. Surface metal raceway enclosures providing a transition from other wiring methods shall have a means for connecting an equipment grounding conductor.

386.70 Combination Raceways. When combination sur- face metallic raceways are used for both signaling and