Section E3801 General Requirements

This chapter covers the wiring methods for services, feeders and branch circuits for electrical power and distribution. (300.1)

The allowable wiring methods for electrical installations shall be those listed in Table E3801.2. Single conductors shall be used only where part of one of the recognized wiring methods listed in Table E3801.2. As used in this code, abbreviations of the wiring-method types shall be as indicated in Table E3801.2. [110.8, 300.3(A)]

TABLE E3801.2 ALLOWABLE WIRING METHODS

ALLOWABLE WIRING METHOD	DESIGNATED ABBREVIATION
Armored cable	AC
Electrical metallic tubing	EMT
Electrical nonmetallic tubing	ENT
Flexible metal conduit	FMC
Intermediate metal conduit	IMC
Liquidtight flexible conduit	LFC
Metal-clad cable	MC
Nonmetallic sheathed cable	NM
Rigid polyvinyl chloride conduit (Type PVC)	RNC
Rigid metallic conduit	RMC
Service entrance cable	SE
Surface raceways	SR
Underground feeder cable	UF
Underground service cable	USE

All conductors of a circuit, including equipment grounding conductors and bonding conductors, shall be contained in the same raceway, trench, cable or cord. [300.3(B)]

Wiring methods shall be applied in accordance with Table E3801.4. (Chapter 3 and 300.2)

TABLE E3801.4 (Chapter 3 and 300.2) ALLOWABLE APPLICATIONS FOR WIRING METHODS^{a, b, c, d, e, f, g, h, i, j, k}

ALLOWABLE APPLICATIONS (application allowed where marked with an "A")

AC

EMT

ENT

FMC

IMC RMC RNC

LFCa, g

MC

NM

SR

SE

UF

USE

Services

‒

A

Ah

Ai

A

Ai

A

‒

‒

A

‒

A

Feeders

A

A

A

A

A

A

A

A

‒

Ab

A

Ab

Branch circuits

A

A

A

A

A

A

A

A

A

Ac

A

‒

Inside a building

A

A

A

A

A

A

A

A

A

A

A

‒

Wet locations exposed to sunlight

‒

A

Ah

‒

A

A

A

‒

‒

A

Ae

Ae

Damp locations

‒

A

A

Ad

A

A

A

‒

‒

A

A

A

Embedded in noncinder concrete in dry location

‒

A

A

‒

A

Aj

‒

‒

‒

‒

‒

‒

In noncinder concrete in contact with grade

‒

Af

A

‒

Af

Aj

‒

‒

‒

‒

‒

‒

Embedded in plaster not exposed to dampness

A

A

A

A

A

A

A

‒

‒

A

A

‒

Embedded in masonry

‒

A

A

‒

Af

A

A

‒

‒

‒

‒

‒

In masonry voids and cells exposed to dampness or below grade line

‒

Af

A

Ad

Af

A

A

‒

‒

A

A

‒

Fished in masonry voids

A

‒

‒

A

‒

A

A

A

‒

A

A

‒

In masonry voids and cells not exposed to dampness

A

A

A

A

A

A

A

A

‒

A

A

‒

Run exposed

A

A

A

A

A

A

A

A

A

A

A

‒

Run exposed and subject to physical damage

‒

‒

‒

‒

Ag

‒

‒

‒

‒

‒

‒

‒

For direct burial

‒

Af

‒

‒

Af

A

Af

‒

‒

‒

A

A

For SI: 1 foot = 304.8 mm.

a. Liquid-tight flexible nonmetallic conduit without integral reinforcement within the conduit wall shall not exceed 6 feet in length.

b. Type USE cable shall not be used inside buildings.

c. The grounded conductor shall be insulated.

d. Conductors shall be a type approved for wet locations and the installation shall prevent water from entering other raceways.

e. Shall be listed as "Sunlight Resistant."

f. Metal raceways shall be protected from corrosion and approved for the application. Aluminum RMC requires approved supplementary corrosion protection.

g. RNC shall be Schedule 80.

h. Shall be listed as "Sunlight Resistant" where exposed to the direct rays of the sun.

i. Conduit shall not exceed 6 feet in length.

j. Liquid-tight flexible nonmetallic conduit is permitted to be encased in concrete where listed for direct burial and only straight connectors listed for use with LFNC are used.

k. In wet locations under any of the following conditions:

1. The metallic covering is impervious to moisture.

2. A lead sheath or moisture-impervious jacket is provided under the metal covering.

3. The insulated conductors under the metallic covering are listed for use in wet locations and a corrosion-resistant jacket is provided over the metallic sheath.