CODES

ADOPTS WITHOUT AMENDMENTS:

International Residential Code 2015 (IRC 2015)

Copyright

Preface

Effective Use of the International Residential Code

Legislation

Part I ‒ Administrative

Chapter 1 Scope and Administration

Part II ‒ Definitions

Chapter 2 Definitions

Part III ‒ Building Planning and Construction

Chapter 3 Building Planning

Chapter 4 Foundations

Chapter 5 Floors

Chapter 6 Wall Construction

Chapter 7 Wall Covering

Chapter 8 Roof-Ceiling Construction

Chapter 9 Roof Assemblies

Chapter 10 Chimneys and Fireplaces

Part IV ‒ Energy Conservation

Chapter 11 [RE] Energy Efficiency

Part V ‒ Mechanical

Chapter 12 Mechanical Administration

Chapter 13 General Mechanical System Requirements

Chapter 14 Heating and Cooling Equipment and Appliances

Chapter 15 Exhaust Systems

Chapter 16 Duct Systems

Chapter 17 Combustion Air

Chapter 18 Chimneys and Vents

Chapter 19 Special Appliances, Equipment and Systems

Chapter 20 Boilers and Water Heaters

Chapter 21 Hydronic Piping

Chapter 22 Special Piping and Storage Systems

Chapter 23 Solar Thermal Energy Systems

Part VI ‒ Fuel Gas

Chapter 24 Fuel Gas

Part VII ‒ Plumbing

Chapter 25 Plumbing Administration

Chapter 26 General Plumbing Requirements

Chapter 27 Plumbing Fixtures

Chapter 28 Water Heaters

Chapter 29 Water Supply and Distribution

Chapter 30 Sanitary Drainage

Chapter 31 Vents

Chapter 32 Traps

Chapter 33 Storm Drainage

Part VIII ‒ Electrical

Chapter 34 General Requirements

Chapter 35 Electrical Definitions

Chapter 36 Services

Chapter 37 Branch Circuit and Feeder Requirements

Chapter 38 Wiring Methods

Chapter 39 Power and Lighting Distribution

Chapter 40 Devices and Luminaires

Chapter 41 Appliance Installation

Chapter 42 Swimming Pools

Chapter 43 Class 2 Remote-Control, Signaling and Power-Limited Circuits

Part IX ‒ Referenced Standards

Chapter 44 Referenced Standards

Appendix A Sizing and Capacities of Gas Piping

Appendix B Sizing of Venting Systems Serving Appliances Equipped With Draft Hoods, Category I Appliances, and Appliances Listed for Use With Type B Vents

Appendix C Exit Terminals of Mechanical Draft and Direct-Vent Venting Systems

Appendix D Recommended Procedure for Safety Inspection of an Existing Appliance Installation

Appendix E Manufactured Housing Used as Dwellings

Appendix F Passive Radon Gas Controls

Appendix G Piping Standards for Various Applications

Appendix H Patio Covers

Appendix I Private Sewage Disposal

Appendix J Existing Buildings and Structures

Appendix K Sound Transmission

Appendix L Permit Fees

Appendix M HOME DAY CARE—R-3 OCCUPANCY

Appendix N Venting Methods

Appendix O Automatic Vehicular Gates

Appendix P Sizing of Water Piping System

Appendix Q Reserved

Appendix R Light Straw-Clay Construction

Appendix S Strawbale Construction

Appendix T Recommended Procedure for Worst-Case Testing of Atmospheric Venting Systems Under N1102.4 or N1105 Conditions

Appendix U SOLAR-READY PROVISIONS—DETACHED ONE- AND TWO-FAMILY DWELLINGS, MULTIPLE SINGLE- FAMILY DWELLINGS (TOWNHOUSES)

Outlets for receptacles rated at 125 volts, 15- and 20-amperes shall be provided in accordance with Sections E3901.2 through E3901.11. Receptacle outlets required by this section shall be in addition to any receptacle that is:

1. Part of a luminaire or appliance;

2. Located within cabinets or cupboards;

3. Controlled by a wall switch in accordance with Section E3903.2, Exception 1; or

4. Located over 5.5 feet (1676 mm) above the floor.

Permanently installed electric baseboard heaters equipped with factory-installed receptacle outlets, or outlets provided as a separate assembly by the baseboard manufacturer shall be permitted as the required outlet or outlets for the wall space utilized by such permanently installed heaters. Such receptacle outlets shall not be connected to the heater circuits. (210.52)
In every kitchen, family room, dining room, living room, parlor, library, den, sun room, bedroom, recreation room, or similar room or area of dwelling units, receptacle outlets shall be installed in accordance with the general provisions specified in Sections E3901.2.1 through E3901.2.3 (see Figure E3901.2).


For SI: 1 foot = 304.8 mm.


FIGURE E3901.2 GENERAL USE RECEPTACLE DISTRIBUTION
Receptacles shall be installed so that no point measured horizontally along the floor line of any wall space is more than 6 feet (1829 mm), from a receptacle outlet. [210.52(A)(1)]
As used in this section, a wall space shall include the following: [210.52(A)(2)]

1. Any space that is 2 feet (610 mm) or more in width, including space measured around corners, and that is unbroken along the floor line by doorways and similar openings, fireplaces, and fixed cabinets.

2. The space occupied by fixed panels in exterior walls, excluding sliding panels.

3. The space created by fixed room dividers such as railings and freestanding bar-type counters.
Receptacle outlets in floors shall not be counted as part of the required number of receptacle outlets except where located within 18 inches (457 mm) of the wall. [210.52(A)(3)]
Receptacles installed for countertop surfaces as specified in Section E3901.4 shall not be considered as the receptacles required by Section E3901.2. [210.52(A)(4)]
In the kitchen, pantry, breakfast room, dining room, or similar area of a dwelling unit, the two or more 20-ampere small-appliance branch circuits required by Section E3703.2, shall serve all wall and floor receptacle outlets covered by Sections E3901.2 and E3901.4 and those receptacle outlets provided for refrigeration appliances. [210.52(B)(1)]

Exceptions:

1. In addition to the required receptacles specified by Sections E3901.1 and E3901.2, switched receptacles supplied from a general-purpose branch circuit as defined in Section E3903.2, Exception 1 shall be permitted. [210.52(B)(1) Exception No. 1]

2. The receptacle outlet for refrigeration appliances shall be permitted to be supplied from an individual branch circuit rated at 15 amperes or greater. [210.52(B)(1) Exception No. 2]
The two or more small-appliance branch circuits specified in Section E3901.3 shall serve no other outlets. [210.52(B)(2)]

Exceptions:

1. A receptacle installed solely for the electrical supply to and support of an electric clock in any of the rooms specified in Section E3901.3. [210.52(B)(2) Exception No.1]

2. Receptacles installed to provide power for supplemental equipment and lighting on gas-fired ranges, ovens, and counter-mounted cooking units. [210.52(B)(2) Exception No.2]
Receptacles installed in a kitchen to serve countertop surfaces shall be supplied by not less than two small-appliance branch circuits, either or both of which shall also be permitted to supply receptacle outlets in the same kitchen and in other rooms specified in Section E3901.3. Additional small-appliance branch circuits shall be permitted to supply receptacle outlets in the kitchen and other rooms specified in Section E3901.3. A small-appliance branch circuit shall not serve more than one kitchen. [210.52(B)(3)]
In kitchens pantries, breakfast rooms, dining rooms and similar areas of dwelling units, receptacle outlets for countertop spaces shall be installed in accordance with Sections E3901.4.1 through E3901.4.5 (see Figure E3901.4). [210.52(C)]


For SI: 1 foot = 304.8 mm


FIGURE E3901.4 COUNTERTOP RECEPTACLES
A receptacle outlet shall be installed at each wall countertop space 12 inches (305 mm) or wider. Receptacle outlets shall be installed so that no point along the wall line is more than 24 inches (610 mm), measured horizontally from a receptacle outlet in that space. [210.52(C)(1)]

Exception: Receptacle outlets shall not be required on a wall directly behind a range, counter-mounted cooking unit or sink in the installation described in Figure E3901.4.1. [210.52(C)(1) Exception]


For SI: 1 inch = 25.4 mm.


FIGURE E3901.4.1 DETERMINATION OF AREA BEHIND SINK OR RANGE
At least one receptacle outlet shall be installed at each island countertop space with a long dimension of 24 inches (610 mm) or greater and a short dimension of 12 inches (305 mm) or greater. [210.52(C)(2)]
At least one receptacle outlet shall be installed at each peninsular countertop space with a long dimension of 24 inches (610 mm) or greater and a short dimension of 12 inches (305 mm) or greater. A peninsular countertop is measured from the connecting edge. [210.52(C)(3)]
Countertop spaces separated by range tops, refrigerators, or sinks shall be considered as separate countertop spaces in applying the requirements of Sections E3901.4.1, E3901.4.2 and E3901.4.3. Where a range, counter-mounted cooking unit, or sink is installed in an island or peninsular countertop and the depth of the countertop behind the range, counter-mounted cooking unit, or sink is less than 12 inches (305 mm), the range, counter-mounted cooking unit, or sink has divided the countertop space into two separate countertop spaces as defined in Section E3901.4.4. Each separate countertop space shall comply with the applicable requirements of this section. [210.52(C)(4)]
Receptacle outlets shall be located not more than 20 inches (508 mm) above the countertop. Receptacle outlet assemblies installed in countertops shall be listed for the application. Receptacle outlets shall not be installed in a face-up position in the work surfaces or countertops. Receptacle outlets rendered not readily accessible by appliances fastened in place, appliance garages, sinks or rangetops as addressed in the exception to Section E3901.4.1, or appliances occupying dedicated space shall not be considered as these required outlets. [210.52(C)(5)]

Exception: Receptacle outlets shall be permitted to be mounted not more than 12 inches (305 mm) below the countertop in construction designed for the physically impaired and for island and peninsular countertops where the countertop is flat across its entire surface and there are no means to mount a receptacle within 20 inches (508 mm) above the countertop, such as in an overhead cabinet. Receptacles mounted below the countertop in accordance with this exception shall not be located where the countertop extends more than 6 inches (152 mm) beyond its support base. [210.52(C)(5) Exception]
Appliance receptacle outlets installed for specific appliances, such as laundry equipment, shall be installed within 6 feet (1829 mm) of the intended location of the appliance. (210.50(C)]
At least one wall receptacle outlet shall be installed in bathrooms and such outlet shall be located within 36 inches (914 mm) of the outside edge of each lavatory basin. The receptacle outlet shall be located on a wall or partition that is adjacent to the lavatory basin location, located on the countertop, or installed on the side or face of the basin cabinet. The receptacle shall be located not more than 12 inches (305 mm) below the top of the basin.

Receptacle outlets shall not be installed in a face-up position in the work surfaces or countertops in a bathroom basin location. Receptacle outlet assemblies installed in countertops shall be listed for the application. [210.52(D)]
Not less than one receptacle outlet that is readily accessible from grade level and located not more than 6 feet, 6 inches (1981 mm) above grade, shall be installed outdoors at the front and back of each dwelling unit having direct access to grade level. Balconies, decks, and porches that are accessible from inside of the dwelling unit shall have at least one receptacle outlet installed within the perimeter of the balcony, deck, or porch. The receptacle shall be located not more than 6 feet, 6 inches (1981 mm) above the balcony, deck, or porch surface. [210.52(E)]
Not less than one receptacle outlet shall be installed in areas designated for the installation of laundry equipment.
Not less than one receptacle outlet, in addition to any provided for specific equipment, shall be installed in each separate unfinished portion of a basement, in each attached garage, and in each detached garage or accessory building that is provided with electrical power. The branch circuit supplying the receptacle(s) in a garage shall not supply outlets outside of the garage and not less than one receptacle outlet shall be installed for each motor vehicle space. [210.52(G)(1), (2), and (3)]
Hallways of 10 feet (3048 mm) or more in length shall have at least one receptacle outlet. The hall length shall be considered the length measured along the centerline of the hall without passing through a doorway. [210.52(H)]
Foyers that are not part of a hallway in accordance with Section E3901.10 and that have an area that is greater than 60 ft2 (5.57 m2) shall have a receptacle(s) located in each wall space that is 3 feet (914 mm) or more in width. Doorways, door-side windows that extend to the floor, and similar openings shall not be considered as wall space. [210.52(H)]
A 125-volt, single-phase, 15- or 20-ampere-rated receptacle outlet shall be installed at an accessible location for the servicing of heating, air-conditioning and refrigeration equipment. The receptacle shall be located on the same level and within 25 feet (7620 mm) of the heating, air-conditioning and refrigeration equipment. The receptacle outlet shall not be connected to the load side of the HVAC equipment disconnecting means. (210.63)

Exception: A receptacle outlet shall not be required for the servicing of evaporative coolers. (210.63 Exception)
125-volt, single-phase, 15- and 20-ampere receptacles installed in bathrooms shall have ground-fault circuit-interrupter protection for personnel. [210.8(A)(1)]
125-volt, single-phase, 15- or 20-ampere receptacles installed in garages and grade-level portions of unfinished accessory buildings used for storage or work areas shall have ground-fault circuit-interrupter protection for personnel. [210.8(A)(2)]
125-volt, single-phase, 15- and 20-ampere receptacles installed outdoors shall have ground-fault circuit-interrupter protection for personnel. [210.8(A)(3)]

Exception: Receptacles as covered in Section E4101.7. [210.8(A)(3) Exception]
Where a crawl space is at or below grade level, 125-volt, single-phase, 15- and 20-ampere receptacles installed in such spaces shall have ground-fault circuit-interrupter protection for personnel. [210.8(A)(4)]
125-volt, single-phase, 15- and 20-ampere receptacles installed in unfinished basements shall have ground-fault circuit-interrupter protection for personnel. For purposes of this section, unfinished basements are defined as portions or areas of the basement not intended as habitable rooms and limited to storage areas, work areas, and similar areas. [210.8(A)(5)]

Exception: A receptacle supplying only a permanently installed fire alarm or burglar alarm system. Receptacles installed in accordance with this exception shall not be considered as meeting the requirement of Section E3901.9. [210.8(A)(5) Exception]
125-volt, single-phase, 15- and 20-ampere receptacles that serve countertop surfaces shall have ground-fault circuit-interrupter protection for personnel. [210.8(A)(6)]
125-volt, single-phase, 15- and 20-ampere receptacles that are located within 6 feet (1829 mm) of the outside edge of a sink shall have ground-fault circuit-interrupter protection for personnel. Receptacle outlets shall not be installed in a face-up position in the work surfaces or countertops. [210.8(A)(7)]
125-volt, single phase, 15- and 20-ampere receptacles that are located within 6 feet (1829 mm) of the outside edge of a bathtub or shower stall shall have ground-fault circuit interrupter protection for personnel. [210.8(A)(8)]
125-volt, single-phase, 15- and 20-ampere receptacles installed in laundry areas shall have ground-fault circuit interrupter protection for personnel. [210.8(A)(9)]
Ground-fault circuit-interrupter protection shall be provided for outlets that supply dishwashers in dwelling unit locations. [210.8(D)]
125-volt, single-phase, 15- or 20-ampere receptacles installed in boathouses shall have ground-fault circuit-interrupter protection for personnel. [210.8(A)(8)]
Ground-fault circuit-interrupter protection for personnel shall be provided for 240-volt and less outlets that supply boat hoists. [210.8(C)]
Ground-fault circuit-interrupter protection for personnel shall be provided for electrically heated floors in bathrooms, kitchens and in hydromassage bathtub, spa and hot tub locations. [424.44(G)]
Ground-fault circuit interrupters shall be installed in a readily accessible location. [210.8(A)]
Arc-fault circuit interrupters shall be installed in readily accessible locations.
Branch circuits that supply 120-volt, single-phase, 15- and 20-ampere outlets installed in kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreations rooms, closets, hallways, laundry areas and similar rooms or areas shall be protected by any of the following: [210.12(A)]

1. A listed combination-type arc-fault circuit interrupter, installed to provide protection of the entire branch circuit. [210.12(A)(1)]

2. A listed branch/feeder-type AFCI installed at the origin of the branch-circuit in combination with a listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet box on the branch circuit. The first outlet box in the branch circuit shall be marked to indicate that it is the first outlet of the circuit. [210.12(A)(2)]

3. A listed supplemental arc protection circuit breaker installed at the origin of the branch circuit in combination with a listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet box on the branch circuit where all of the following conditions are met:

3.1. The branch-circuit wiring shall be continuous from the branch-circuit overcurrent device to the outlet branch-circuit arc-fault circuit interrupter.

3.2. The maximum length of the branch-circuit wiring from the branch-circuit overcurrent device to the first outlet shall not exceed 50 feet (15.2 m) for 14 AWG conductors and 70 feet (21.3 m) for 12 AWG conductors.

3.3. The first outlet box on the branch circuit shall be marked to indicate that it is the first outlet on the circuit. [210.12(A)(3)]

4. A listed outlet branch-circuit type arc-fault circuit interrupter installed at the first outlet on the branch circuit in combination with a listed branch-circuit overcurrent protective device where all of the following conditions are met:

4.1. The branch-circuit wiring shall be continuous from the branch-circuit overcurrent device to the outlet branch-circuit arc-fault circuit interrupter.

4.2. The maximum length of the branch-circuit wiring from the branch-circuit overcurrent device to the first outlet shall not exceed 50 feet (15.2 m) for 14 AWG conductors and 70 feet (21.3 m) for 12 AWG conductors.

4.3. The first outlet box on the branch circuit shall be marked to indicate that it is the first outlet on the circuit.

4.4. The combination of the branch-circuit overcurrent device and outlet branch-circuit AFCI shall be identified as meeting the requirements for a system combination-type AFCI and shall be listed as such. [210.12(A)(4)]

5. Where metal outlet boxes and junction boxes and RMC, IMC, EMT, Type MC or steel-armored Type AC cables meeting the requirements of Section E3908.8, metal wireways or metal auxiliary gutters are installed for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, a listed outlet branch-circuit type AFCI installed at the first outlet shall be considered as providing protection for the remaining portion of the branch circuit. [210.12(A)(5)]

6. Where a listed metal or nonmetallic conduit or tubing or Type MC cable is encased in not less than 2 inches (50.8 mm) of concrete for the portion of the branch circuit between the branch-circuit overcurrent device and the first outlet, a listed outlet branch-circuit type AFCI installed at the first outlet shall be considered as providing protection for the remaining portion of the branch circuit. [210.12(A)(6)]

Exception: AFCI protection is not required for an individual branch circuit supplying only a fire alarm system where the branch circuit is wired with metal outlet and junction boxes and RMC, IMC, EMT or steel-sheathed armored cable Type AC or Type MC meeting the requirements of Section E3908.8.
Where branch-circuit wiring is modified, replaced, or extended in any of the areas specified in Section E3902.16, the branch circuit shall be protected by one of the following:

1. A combination-type AFCI located at the origin of the branch circuit

2. An outlet branch-circuit type AFCI located at the first receptacle outlet of the existing branch circuit. [210.12(B)]

Exception: AFCI protection shall not be required where the extension of the existing conductors is not more than 6 feet (1.8 m) in length and does not include any additional outlets or devices. [210.12(B) Exception]
Lighting outlets shall be provided in accordance with Sections E3903.2 through E3903.4. [210.70(A)]
At least one wall switch-controlled lighting outlet shall be installed in every habitable room and bathroom. [210.70(A)(1)]

Exceptions:

1. In other than kitchens and bathrooms, one or more receptacles controlled by a wall switch shall be considered equivalent to the required lighting outlet. [210.70(A)(1) Exception No. 1]

2. Lighting outlets shall be permitted to be controlled by occupancy sensors that are in addition to wall switches, or that are located at a customary wall switch location and equipped with a manual override that will allow the sensor to function as a wall switch. [210.70(A)(1) Exception No. 2]
At least one wall-switch-controlled lighting outlet shall be installed in hallways, stairways, attached garages, and detached garages with electric power. At least one wall-switch-controlled lighting outlet shall be installed to provide illumination on the exterior side of each outdoor egress door having grade level access, including outdoor egress doors for attached garages and detached garages with electric power. A vehicle door in a garage shall not be considered as an outdoor egress door. Where one or more lighting outlets are installed for interior stairways, there shall be a wall switch at each floor level and landing level that includes an entryway to control the lighting outlets where the stairway between floor levels has six or more risers. [210.70(A)(2)]

Exception: In hallways, stairways, and at outdoor egress doors, remote, central, or automatic control of lighting shall be permitted. [210.70(A)(2) Exception]
In attics, under-floor spaces, utility rooms and basements, at least one lighting outlet shall be installed where these spaces are used for storage or contain equipment requiring servicing. Such lighting outlet shall be controlled by a wall switch or shall have an integral switch. At least one point of control shall be at the usual point of entry to these spaces. The lighting outlet shall be provided at or near the equipment requiring servicing. [210.70(A)(3)]
Metal raceways, cable armor and other metal enclosures for conductors shall be mechanically joined together into a continuous electric conductor and shall be connected to all boxes, fittings and cabinets so as to provide effective electrical continuity. Raceways and cable assemblies shall be mechanically secured to boxes, fittings cabinets and other enclosures. (300.10)

Exception: Short sections of raceway used to provide cable assemblies with support or protection against physical damage. (300.10 Exception No. 1)
Metal or nonmetallic raceways, cable armors and cable sheaths shall be continuous between cabinets, boxes, fittings or other enclosures or outlets.

Exception: Short sections of raceway used to provide cable assemblies with support or protection against physical damage. (300.12 Exception No. 1)
Raceways, cable assemblies, boxes, cabinets and fittings shall be securely fastened in place. (300.11)
Cable wiring methods shall not be used as a means of support for other cables, raceways and nonelectrical equipment. [300.11(C)]
Raceways shall be used as a means of support for other raceways, cables or nonelectric equipment only under the following conditions:

1. Where the raceway or means of support is identified as a means of support; or

2. Where the raceway contains power supply conductors for electrically controlled equipment and is used to support Class 2 circuit conductors or cables that are solely for the purpose of connection to the control circuits of the equipment served by such raceway; or

3. Where the raceway is used to support boxes or conduit bodies in accordance with Sections E3906.8.4 and E3906.8.5. [300.11(B)]
Raceways shall be installed complete between outlet, junction or splicing points prior to the installation of conductors. (300.18)

Exception: Short sections of raceways used to contain conductors or cable assemblies for protection from physical damage shall not be required to be installed complete between outlet, junction, or splicing points. (300.18 Exception)
The maximum number of conductors installed in conduit or tubing shall be in accordance with Tables E3904.6(1) through E3904.6(10). (300.17, Chapter 9, Table 1 and Annex C)

TABLE E3904.6(1) (Annex C, Table C.1) MAXIMUM NUMBER OF CONDUCTORS IN ELECTRICAL METALLIC TUBING (EMT)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 4 7 11 20 27 46
12 3 6 9 17 23 38
10 2 5 8 13 18 30
8 1 2 4 7 9 16
6 1 1 3 5 8 13
4 1 1 2 4 6 10
3 1 1 1 4 5 9
2 1 1 1 3 4 7
1 0 1 1 1 3 5
1/0 0 1 1 1 2 4
2/0 0 1 1 1 2 4
3/0 0 0 1 1 1 3
4/0 0 0 1 1 1 3
TW, THHW, THW, THW-2 14 8 15 25 43 58 96
12 6 11 19 33 45 74
10 5 8 14 24 33 55
8 2 5 8 13 18 30
RHHa, RHWa, RHW-2a 14 6 10 16 28 39 64
12 4 8 13 23 31 51
10 3 6 10 18 24 40
8 1 4 6 10 14 24
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 3 4 8 11 18
4 1 1 3 6 8 13
3 1 1 3 5 7 12
2 1 1 2 4 6 10
1 1 1 1 3 4 7
1/0 0 1 1 2 3 6
2/0 0 1 1 1 3 5
3/0 0 1 1 1 2 4
4/0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 12 22 35 61 84 138
12 9 16 26 45 61 101
10 5 10 16 28 38 63
8 3 6 9 16 22 36
6 2 4 7 12 16 26
4 1 2 4 7 10 16
3 1 1 3 6 8 13
2 1 1 3 5 7 11
1 1 1 1 4 5 8
1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4
XHH, XHHW, XHHW-2 14 8 15 25 43 58 96
12 6 11 19 33 45 74
10 5 8 14 24 33 55
8 2 5 8 13 18 30
6 1 3 6 10 14 22
4 1 2 4 7 10 16
3 1 1 3 6 8 14
2 1 1 3 5 7 11
1 1 1 1 4 5 8
1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(2) (Annex C, Table C.2) MAXIMUM NUMBER OF CONDUCTORS IN ELECTRICAL NONMETALLIC TUBING (ENT)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 3 6 10 19 26 43
12 2 5 9 16 22 36
10 1 4 7 13 17 29
8 1 1 3 6 9 15
6 1 1 3 5 7 12
4 1 1 2 4 6 9
3 1 1 1 3 5 8
2 0 1 1 3 4 7
1 0 1 1 1 3 5
1/0 0 0 1 1 2 4
2/0 0 0 1 1 1 3
RHH, RHW, RHW-2 3/0 0 0 1 1 1 3
4/0 0 0 1 1 1 2
TW, THHW, THW, THW-2 14 7 13 22 40 55 92
12 5 10 17 31 42 71
10 4 7 13 23 32 52
8 1 4 7 13 17 29
RHHa, RHWa, RHW-2a 14 4 8 15 27 37 61
12 3 7 12 21 29 49
10 3 5 9 17 23 38
8 1 3 5 10 14 23
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 2 4 7 10 17
4 1 1 3 5 8 13
3 1 1 2 5 7 11
2 1 1 2 4 6 9
1 0 1 1 3 4 6
1/0 0 1 1 2 3 5
2/0 0 1 1 1 3 5
3/0 0 0 1 1 2 4
4/0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 10 18 32 58 80 132
12 7 13 23 42 58 96
10 4 8 15 26 36 60
8 2 5 8 15 21 35
6 1 3 6 11 15 25
4 1 1 4 7 9 15
3 1 1 3 5 8 13
2 1 1 2 5 6 11
THHN, THWN, THWN-2 1 1 1 1 3 5 8
1/0 0 1 1 3 4 7
2/0 0 1 1 2 3 5
3/0 0 1 1 1 3 4
4/0 0 0 1 1 2 4
XHH, XHHW, XHHW-2 14 7 13 22 40 55 92
12 5 10 17 31 42 71
10 4 7 13 23 32 52
8 1 4 7 13 17 29
6 1 3 5 9 13 21
4 1 1 4 7 9 15
3 1 1 3 6 8 13
2 1 1 2 5 6 11
1 1 1 1 3 5 8
1/0 0 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 0 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(3) (Annex C, Table C.3) MAXIMUM NUMBER OF CONDUCTORS IN FLEXIBLE METALLIC CONDUIT (FMC)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 4 7 11 17 25 44
12 3 6 9 14 21 37
10 3 5 7 11 17 30
8 1 2 4 6 9 15
6 1 1 3 5 7 12
4 1 1 2 4 5 10
3 1 1 1 3 5 7
RHH, RHW, RHW-2 2 1 1 1 3 4 7
1 0 1 1 1 2 5
1/0 0 1 1 1 2 4
2/0 0 1 1 1 1 3
3/0 0 0 1 1 1 3
TW, THHW, THW, THW-2 14 9 15 23 36 53 94
12 7 11 18 28 41 72
10 5 8 13 21 30 54
8 3 5 7 11 17 30
RHHa, RHWa, RHW-2a 14 6 10 15 24 35 62
12 5 8 12 19 28 50
10 4 6 10 15 22 39
8 1 4 6 9 13 23
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 3 4 7 10 18
4 1 1 3 5 7 13
3 1 1 3 4 6 11
2 1 1 2 4 5 10
1 1 1 1 2 4 7
1/0 0 1 1 1 3 6
2/0 0 1 1 1 3 5
3/0 0 1 1 1 2 4
4/0 0 0 1 1 1 3
4/0 0 0 1 1 1 2
THHN, THWN, THWN-2 14 13 22 33 52 76 134
12 9 16 24 38 56 98
10 6 10 15 24 35 62
8 3 6 9 14 20 35
THHN, THWN, THWN-2 6 2 4 6 10 14 25
4 1 2 4 6 9 16
3 1 1 3 5 7 13
2 1 1 3 4 6 11
1 1 1 1 3 4 8
1/0 1 1 1 2 4 7
2/0 0 1 1 1 3 6
3/0 0 1 1 1 2 5
4/0 0 1 1 1 1 4
XHH, XHHW, XHHW-2 14 9 15 23 36 53 94
12 7 11 18 28 41 72
10 5 8 13 21 30 54
8 3 5 7 11 17 30
6 1 3 5 8 12 22
4 1 2 4 6 9 16
3 1 1 3 5 7 13
2 1 1 3 4 6 11
1 1 1 1 3 5 8
1/0 1 1 1 2 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(4) (Annex C, Table C.4) MAXIMUM NUMBER OF CONDUCTORS IN INTERMEDIATE METALLIC CONDUIT (IMC)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 4 8 13 22 30 49
12 4 6 11 18 25 41
10 3 5 8 15 20 33
8 1 3 4 8 10 17
6 1 1 3 6 8 14
4 1 1 3 5 6 11
3 1 1 2 4 6 9
2 1 1 1 3 5 8
1 0 1 1 2 3 5
1/0 0 1 1 1 3 4
2/0 0 1 1 1 2 4
3/0 0 0 1 1 1 3
4/0 0 0 1 1 1 3
TW, THHW, THW, THW-2 14 10 17 27 47 64 104
12 7 13 21 36 49 80
10 5 9 15 27 36 59
8 3 5 8 15 20 33
RHHa, RHWa, RHW-2a 14 6 11 18 31 42 69
12 5 9 14 25 34 56
10 4 7 11 19 26 43
8 2 4 7 12 16 26
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 3 5 9 12 20
4 1 2 4 6 9 15
3 1 1 3 6 8 13
2 1 1 3 5 6 11
1 1 1 1 3 4 7
1/0 1 1 1 3 4 6
2/0 0 1 1 2 3 5
3/0 0 1 1 1 3 4
4/0 0 1 1 1 2 4
THHN, THWN, THWN-2 14 14 24 39 68 91 149
12 10 17 29 49 67 109
10 6 11 18 31 42 68
8 3 6 10 18 24 39
6 2 4 7 13 17 28
4 1 3 4 8 10 17
3 1 2 4 6 9 15
2 1 1 3 5 7 12
1 1 1 2 4 5 9
1/0 1 1 1 3 4 8
2/0 1 1 1 3 4 6
THHN, THWN, THWN-2 3/0 0 1 1 2 3 5
2/0 0 1 1 1 2 4
XHH, XHHW, XHHW-2 14 10 17 27 47 64 104
12 7 13 21 36 49 80
10 5 9 15 27 36 59
8 3 5 8 15 20 33
6 1 4 6 11 15 24
4 1 3 4 8 11 18
3 1 2 4 7 9 15
2 1 1 3 5 7 12
1 1 1 2 4 5 9
1/0 1 1 1 3 5 8
2/0 1 1 1 3 4 6
3/0 0 1 1 2 3 5
4/0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(5) (Annex C, Table C.5) MAXIMUM NUMBER OF CONDUCTORS IN LIQUID-TIGHT FLEXIBLE NONMETALLIC CONDUIT (FNMC-B)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
3/8 1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 2 4 7 12 21 27 44
12 1 3 6 10 17 22 36
10 1 3 5 8 14 18 29
8 1 1 2 4 7 9 1
6 1 1 1 3 6 7 12
4 0 1 1 2 4 6 9
RHH, RHW, RHW-2 3 0 1 1 1 4 5 8
2 0 1 1 1 3 4 7
1 0 0 1 1 1 3 5
1/0 0 0 1 1 1 2 4
2/0 0 0 1 1 1 1 3
3/0 0 0 0 1 1 1 3
4/0 0 0 0 1 1 1 2
TW, THHW, THW, THW-2 14 5 9 15 25 44 57 93
12 4 7 12 19 33 43 71
10 3 5 9 14 25 32 53
8 1 3 5 8 14 18 29
RHHa, RHWa, RGW-2a 14 3 6 10 16 29 38 62
12 3 5 8 13 23 30 50
10 1 3 6 10 18 23 39
8 1 1 4 6 11 14 23
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 1 3 5 8 11 18
4 1 1 1 3 6 8 13
3 1 1 1 3 5 7 11
2 0 1 1 2 4 6 9
1 0 1 1 1 3 4 7
1/0 0 0 1 1 2 3 6
2/0 0 0 1 1 2 3 5
3/0 0 0 1 1 1 2 4
4/0 0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 8 13 22 36 63 81 133
12 5 9 16 26 46 59 97
10 3 6 10 16 29 37 61
8 1 3 6 9 16 21 35
THHN, THWN, THWN-2 6 1 2 4 7 12 15 25
4 1 1 2 4 7 9 15
3 1 1 1 3 6 8 13
2 1 1 1 3 5 7 11
1 0 1 1 1 4 5 8
1/0 0 1 1 1 3 4 7
2/0 0 0 1 1 2 3 6
3/0 0 0 1 1 1 3 5
4/0 0 0 1 1 1 2 4
XHH, XHHW, XHHW-2 14 5 9 15 25 44 57 93
12 4 7 12 19 33 43 71
10 3 5 9 14 25 32 53
8 1 3 5 8 14 18 29
6 1 1 3 6 10 13 22
4 1 1 2 4 7 9 16
3 1 1 1 3 6 8 13
2 1 1 1 3 5 7 11
1 0 1 1 1 4 5 8
1/0 0 1 1 1 3 4 7
2/0 0 0 1 1 2 3 6
3/0 0 0 1 1 1 3 5
4/0 0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(6) (Annex C, Table C.6) MAXIMUM NUMBER OF CONDUCTORS IN LIQUID-TIGHT FLEXIBLE NONMETALLIC CONDUIT (FNMC-A)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
3/8 1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 2 4 7 11 20 27 45
12 1 3 6 9 17 23 38
10 1 3 5 8 13 18 30
8 1 1 2 4 7 9 16
6 1 1 1 3 5 7 13
4 0 1 1 2 4 6 10
3 0 1 1 1 4 5 8
2 0 1 1 1 3 4 7
1 0 0 1 1 1 3 5
1/0 0 0 1 1 1 2 4
2/0 0 0 1 1 1 1 4
3/0 0 0 0 1 1 1 3
4/0 0 0 0 1 1 1 3
TW, THHW, THW, THW-2 14 5 9 15 24 43 58 96
12 4 7 12 19 33 44 74
10 3 5 9 14 24 33 55
8 1 3 5 8 13 18 30
RHHa, RHWa, RHW-2a 14 3 6 10 16 28 38 64
12 3 4 8 13 23 31 51
10 1 3 6 10 18 24 40
8 1 1 4 6 10 14 24
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 1 3 4 8 11 18
4 1 1 1 3 6 8 13
3 1 1 1 3 5 7 11
2 0 1 1 2 4 6 10
1 0 1 1 1 3 4 7
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
1/0 0 0 1 1 2 3 6
2/0 0 0 1 1 1 3 5
3/0 0 0 1 1 1 2 4
4/0 0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 8 13 22 35 62 83 137
12 5 9 16 25 45 60 100
10 3 6 10 16 28 38 63
8 1 3 6 9 16 22 36
6 1 2 4 6 12 16 26
4 1 1 2 4 7 9 16
3 1 1 1 3 6 8 13
2 1 1 1 3 5 7 11
1 0 1 1 1 4 5 8
1/0 0 1 1 1 3 4 7
2/0 0 0 1 1 2 3 6
3/0 0 0 1 1 1 3 5
4/0 0 0 1 1 1 2 4
XHH, XHHW, XHHW-2 14 5 9 15 24 43 58 96
12 4 7 12 19 33 44 74
10 3 5 9 14 24 33 55
8 1 3 5 8 13 18 30
6 1 1 3 5 10 13 22
4 1 1 2 4 7 10 16
3 1 1 1 3 6 8 14
2 1 1 1 3 5 7 11
1 0 1 1 1 4 5 8
XHH, XHHW, XHHW-2 1/0 0 1 1 1 3 4 7
2/0 0 0 1 1 2 3 6
3/0 0 0 1 1 1 3 5
4/0 0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(7) (Annex C, Table C.7) MAXIMUM NUMBER OF CONDUCTORS IN LIQUID-TIGHT FLEXIBLE METAL CONDUIT (LFMC)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 4 7 12 21 27 44
12 3 6 10 17 22 36
10 3 5 8 14 18 29
8 1 2 4 7 9 15
6 1 1 3 6 7 12
4 1 1 2 4 6 9
3 1 1 1 4 5 8
2 1 1 1 3 4 7
1 0 1 1 1 3 5
1/0 0 1 1 1 2 4
2/0 0 1 1 1 1 3
3/0 0 0 1 1 1 3
4/0 0 0 1 1 1 2
TW, THHW, THW, THW-2 14 9 15 25 44 57 93
12 7 12 19 33 43 71
10 5 9 14 25 32 53
8 3 5 8 14 18 29
RHHa, RHWa, RHW-2a,
THHW, THW, THW-2
14 6 10 16 29 38 62
12 5 8 13 23 30 50
10 3 6 10 18 23 39
8 1 4 6 11 14 23
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 3 5 8 11 18
4 1 1 3 6 8 13
3 1 1 3 5 7 11
2 1 1 2 4 6 9
1 1 1 1 3 4 7
1/0 0 1 1 2 3 6
2/0 0 1 1 2 3 5
3/0 0 1 1 1 2 4
4/0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 13 22 36 63 81 133
12 9 16 26 46 59 97
10 6 10 16 29 37 61
8 3 6 9 16 21 35
6 2 4 7 12 15 25
4 1 2 4 7 9 15
3 1 1 3 6 8 13
2 1 1 3 5 7 11
1 1 1 1 4 5 8
1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4
XHH, XHHW, XHHW-2 14 9 15 25 44 57 93
12 7 12 19 33 43 71
10 5 9 14 25 32 53
8 3 5 8 14 18 29
XHH, XHHW, XHHW-2 6 1 3 6 10 13 22
4 1 2 4 7 9 16
3 1 1 3 6 8 13
2 1 1 3 5 7 11
1 1 1 1 4 5 8
1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(8) (Annex C, Table C.8) MAXIMUM NUMBER OF CONDUCTORS IN RIGID METAL CONDUIT (RMC)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 4 7 12 21 28 46
12 3 6 10 17 23 38
10 3 5 8 14 19 31
8 1 2 4 7 10 16
6 1 1 3 6 8 13
4 1 1 2 4 6 10
3 1 1 2 4 5 9
2 1 1 1 3 4 7
1 0 1 1 1 3 5
1/0 0 1 1 1 2 4
2/0 0 1 1 1 2 4
3/0 0 0 1 1 1 3
4/0 0 0 1 1 1 3
TW, THHW, THW, THW-2 14 9 15 25 44 59 98
12 7 12 19 33 45 75
10 5 9 14 25 34 56
8 3 5 8 14 19 31
RHHa, RHWa, RHW-2a 14 6 10 17 29 39 65
12 5 8 13 23 32 52
10 3 6 10 18 25 41
8 1 4 6 11 15 24
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 3 5 8 11 18
4 1 1 3 6 8 14
3 1 1 3 5 7 12
2 1 1 2 4 6 10
1 1 1 1 3 4 7
1/0 0 1 1 2 3 6
2/0 0 1 1 2 3 5
3/0 0 1 1 1 2 4
4/0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 13 22 36 63 85 140
12 9 16 26 46 62 102
10 6 10 17 29 39 64
8 3 6 9 16 22 37
6 2 4 7 12 16 27
4 1 2 4 7 10 16
3 1 1 3 6 8 14
2 1 1 3 5 7 11
1 1 1 1 4 5 8
THHN, THWN, THWN-2 1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4
XHH, XHHW, XHHW-2 14 9 15 25 44 59 98
12 7 12 19 33 45 75
10 5 9 14 25 34 56
8 3 5 8 14 19 31
6 1 3 6 10 14 23
4 1 2 4 7 10 16
3 1 1 3 6 8 14
2 1 1 3 5 7 12
1 1 1 1 4 5 9
1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(9) (Annex C, Table C.9) MAXIMUM NUMBER OF CONDUCTORS IN RIGID PVC CONDUIT, SCHEDULE 80 (PVC-80)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 3 5 9 17 23 39
12 2 4 7 14 19 32
10 1 3 6 11 15 26
8 1 1 3 6 8 13
6 1 1 2 4 6 11
4 1 1 1 3 5 8
RHH, RHW, RHW-2 3 0 1 1 3 4 7
2 0 1 1 3 4 6
1 0 1 1 1 2 4
1/0 0 0 1 1 1 3
2/0 0 0 1 1 1 3
3/0 0 0 1 1 1 3
4/0 0 0 0 1 1 2
TW, THHW, THW, THW-2 14 6 11 20 35 49 82
12 5 9 15 27 38 63
10 3 6 11 20 28 47
8 1 3 6 11 15 26
RHHa, RHWa, RHW-2a 14 4 8 13 23 32 55
12 3 6 10 19 26 44
10 2 5 8 15 20 34
8 1 3 5 9 12 20
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 1 3 7 9 16
4 1 1 3 5 7 12
3 1 1 2 4 6 10
2 1 1 1 3 5 8
1 0 1 1 2 3 6
1/0 0 1 1 1 3 5
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
2/0 0 1 1 1 2 4
3/0 0 0 1 1 1 3
4/0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 9 17 28 51 70 118
12 6 12 20 37 51 86
10 4 7 13 23 32 54
8 2 4 7 13 18 31
6 1 3 5 9 13 22
4 1 1 3 6 8 14
3 1 1 3 5 7 12
2 1 1 2 4 6 10
1 0 1 1 3 4 7
1/0 0 1 1 2 3 6
2/0 0 1 1 1 3 5
3/0 0 1 1 1 2 4
4/0 0 0 1 1 1 3
XHH, XHHW, XHHW-2 14 6 11 20 35 49 82
12 5 9 15 27 38 63
10 3 6 11 20 28 47
8 1 3 6 118 15 26
6 1 2 4 11 19


(continued)

TABLE E3904.6(9) (Annex C, Table C.9)‒continued MAXIMUM NUMBER OF CONDUCTORS IN RIGID PVC CONDUIT, SCHEDULE 80 (PVC-80)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
XHH, XHHW, XHHW-2 14 6 11 20 35 49 82
12 5 9 15 27 38 63
10 3 6 11 20 28 47
8 1 3 6 11 15 26
6 1 2 4 8 11 19
4 1 1 3 6 8 14
3 1 1 3 5 7 12
2 1 1 2 4 6 10
1 0 1 1 3 4 7
1/0 0 1 1 2 3 6
2/0 0 1 1 1 3 5
3/0 0 1 1 1 2 4
4/0 0 0 1 1 1 3

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.


TABLE E3904.6(10) (Annex C, Table C.10) MAXIMUM NUMBER OF CONDUCTORS IN RIGID PVC CONDUIT SCHEDULE 40 (PVC-40)a

TYPE LETTERS CONDUCTOR SIZE
AWG/kcmil
TRADE SIZES
(inches)
1/2 3/4 1 11/4 11/2 2
RHH, RHW, RHW-2 14 4 7 11 20 27 45
12 3 5 9 16 22 37
10 2 4 7 13 18 30
8 1 2 4 7 9 15
6 1 1 3 5 7 12
4 1 1 2 4 6 10
3 1 1 1 4 5 8
2 1 1 1 3 4 7
RHH, RHW, RHW-2 1 0 1 1 1 3 5
1/0 0 1 1 1 2 4
2/0 0 0 1 1 1 3
3/0 0 0 1 1 1 3
4/0 0 0 1 1 1 2
TW, THHW, THW, THW-2 14 8 14 24 42 57 94
12 6 11 18 32 44 72
10 4 8 13 24 32 54
8 2 4 7 13 18 30
RHHa, RHWa, RHW-2a 14 5 9 16 28 38 63
12 4 8 13 22 30 50
10 3 6 10 17 24 39
8 1 3 6 10 14 23
RHHa, RHWa, RHW-2a,
TW, THW, THHW, THW-2
6 1 2 4 8 11 18
4 1 1 3 6 8 13
3 1 1 3 5 7 11
2 1 1 2 4 6 10
1 0 1 1 3 4 7
1/0 0 1 1 2 3 6
2/0 0 1 1 1 3 5
3/0 0 1 1 1 2 4
4/0 0 0 1 1 1 3
THHN, THWN, THWN-2 14 11 21 34 60 82 135
12 8 15 25 43 59 99
10 5 9 15 27 37 62
8 3 5 9 16 21 36
THHN, THWN, THWN-2 6 1 4 6 11 15 26
4 1 2 4 7 9 16
3 1 1 3 6 8 13
2 1 1 3 5 7 11
1 1 1 1 3 5 8
1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4
XHH, XHHW, XHHW-2 14 8 14 24 42 57 94
12 6 11 18 32 44 72
10 4 8 13 24 32 54
8 2 4 7 13 18 30
6 1 3 5 10 13 22
4 1 2 4 7 9 16
3 1 1 3 6 8 13
2 1 1 3 5 7 11
1 1 1 1 3 5 8
1/0 1 1 1 3 4 7
2/0 0 1 1 2 3 6
3/0 0 1 1 1 3 5
4/0 0 1 1 1 2 4

For SI: 1 inch = 25.4 mm.
a. Types RHW, and RHW-2 without outer covering.
Where wiring methods having a nonmetallic covering pass through stud cavities and joist spaces used for air handling, such wiring shall pass through such spaces perpendicular to the long dimension of the spaces. [300.22(C) Exception]
A box or conduit body shall be installed at each conductor splice point, outlet, switch point, junction point and pull point except as otherwise permitted in Sections E3905.1.1 through E3905.1.6.

Fittings and connectors shall be used only with the specific wiring methods for which they are designed and listed. (300.15)
An integral junction box or wiring compartment that is part of listed equipment shall be permitted to serve as a box or conduit body. [300.15(B)]
A box or conduit body shall not be required where cables enter or exit from conduit or tubing that is used to provide cable support or protection against physical damage. A fitting shall be provided on the end(s) of the conduit or tubing to protect the cable from abrasion. [300.15(C)]
A wiring device with integral enclosure identified for the use, having brackets that securely fasten the device to walls or ceilings of conventional on-site frame construction, for use with nonmetallic-sheathed cable, shall be permitted in lieu of a box or conduit body. [300.15(E)]
A fitting identified for the use shall be permitted in lieu of a box or conduit body where such fitting is accessible after installation and does not contain spliced or terminated conductors. [300.15(F)]
Splices and taps in buried conductors and cables shall not be required to be enclosed in a box or conduit body where installed in accordance with Section E3803.4.
Where a luminaire is listed to be used as a raceway, a box or conduit body shall not be required for wiring installed therein. [300.15(J)]
Metal boxes shall be grounded. (314.4)
Nonmetallic boxes shall be used only with cabled wiring methods with entirely nonmetallic sheaths, flexible cords and nonmetallic raceways. (314.3)

Exceptions:

1. Where internal bonding means are provided between all entries, nonmetallic boxes shall be permitted to be used with metal raceways and metal-armored cables. (314.3 Exception No. 1)

2. Where integral bonding means with a provision for attaching an equipment grounding jumper inside the box are provided between all threaded entries in nonmetallic boxes listed for the purpose, nonmetallic boxes shall be permitted to be used with metal raceways and metal-armored cables. (314.3 Exception No. 2)
Where nonmetallic-sheathed cable is used, the cable assembly, including the sheath, shall extend into the box not less than 1/4 inch (6.4 mm) through a nonmetallic-sheathed cable knockout opening. (314.7(C)]
Wiring methods shall be secured to the boxes. [314.17(C)]

Exception: Where nonmetallic-sheathed cable is used with boxes not larger than a nominal size of 21/4 inches by 4 inches (57 mm by 102 mm) mounted in walls or ceilings, and where the cable is fastened within 8 inches (203 mm) of the box measured along the sheath, and where the sheath extends through a cable knockout not less than 1/4 inch (6.4 mm), securing the cable to the box shall not be required. [314.17(C) Exception]
Nonmetallic boxes shall be suitable for the lowest temperature-rated conductor entering the box. [314.17(C)]
Outlet and device boxes shall have an approved depth to allow equipment installed within them to be mounted properly and without the likelihood of damage to conductors within the box. (314.24)
Outlet boxes that do not enclose devices or utilization equipment shall have an internal depth of not less than 1/2 inch (12.7 mm). [314.24(A)]
Outlet and device boxes that enclose devices or utilization equipment shall have a minimum internal depth that accommodates the rearward projection of the equipment and the size of the conductors that supply the equipment. The internal depth shall include that of any extension boxes, plaster rings, or raised covers. The internal depth shall comply with all of the applicable provisions that follow. [314.24(B)]

Exception: Utilization equipment that is listed to be installed with specified boxes.

1. Large equipment. Boxes that enclose devices or utilization equipment that projects more than 17/8 inches (48 mm) rearward from the mounting plane of the box shall have a depth that is not less than the depth of the equipment plus 1/4 inch (6.4 mm). [314.24(B)(1)]

2. Conductors larger than 4 AWG. Boxes that enclose devices or utilization equipment supplied by conductors larger than 4 AWG shall be identified for their specific function. [314.24(B)(2)]

3. Conductors 8, 6, or 4 AWG. Boxes that enclose devices or utilization equipment supplied by 8, 6, or 4 AWG conductors shall have an internal depth that is not less than 21/16 inches (52.4 mm). [314.24(B)(3)]

4. Conductors 12 or 10 AWG. Boxes that enclose devices or utilization equipment supplied by 12 or 10 AWG conductors shall have an internal depth that is not less than 13/16 inches (30.2 mm). Where the equipment projects rearward from the mounting plane of the box by more than 1 inch (25.4 mm), the box shall have a depth that is not less than that of the equipment plus 1/4 inch (6.4 mm). [314.24(B)(4)]

5. Conductors 14 AWG and smaller. Boxes that enclose devices or utilization equipment supplied by 14 AWG or smaller conductors shall have a depth that is not less than 15/16 inch (23.8 mm). [314.24(B)(5)]
Boxes enclosing flush-mounted devices shall be of such design that the devices are completely enclosed at the back and all sides and shall provide support for the devices. Screws for supporting the box shall not be used for attachment of the device contained therein. (314.19)
Outlet boxes used at luminaire or lampholder outlets shall be designed for the support of luminaires and lampholders and shall be installed as required by Section E3904.3. [314.27(A)]
Boxes used at luminaire or lampholder outlets in or on a vertical surface shall be identified and marked on the interior of the box to indicate the maximum weight of the luminaire or lamp holder that is permitted to be supported by the box if other than 50 pounds (22.7 kg). [314.27(A)(1)]

Exception: A vertically-mounted luminaire or lampholder weighing not more than 6 pounds (2.7 kg) shall be permitted to be supported on other boxes or plaster rings that are secured to other boxes, provided that the luminaire or its supporting yoke is secured to the box with not fewer than two No. 6 or larger screws. [314.27(A)(1) Exception]
For outlets used exclusively for lighting, the box shall be designed or installed so that a luminaire or lampholder can be attached. Such boxes shall be capable of supporting a luminaire weighing up to 50 pounds (22.7 kg). A luminaire that weighs more than 50 pounds (22.7 kg) shall be supported independently of the outlet box, unless the outlet box is listed and marked on the interior of the box to indicate the maximum weight that the box is permitted to support. [314.27(A)(2)]
Where outlet boxes for receptacles are installed in the floor, such boxes shall be listed specifically for that application. [314.27(B)]
Outlet boxes and outlet box systems used as the sole support of ceiling-suspended fans (paddle) shall be marked by their manufacturer as suitable for this purpose and shall not support ceiling-suspended fans (paddle) that weigh more than 70 pounds (31.8 kg). For outlet boxes and outlet box systems designed to support ceiling-suspended fans (paddle) that weigh more than 35 pounds (15.9 kg), the required marking shall include the maximum weight to be supported.

Where spare, separately switched, ungrounded conductors are provided to a ceiling-mounted outlet box and such box is in a location acceptable for a ceiling-suspended (paddle) fan, the outlet box or outlet box system shall be listed for sole support of a ceiling-suspended (paddle) fan. [314.27(C)]
Boxes used for the support of utilization equipment other than ceiling-suspended (paddle) fans shall meet the requirements of Sections E3905.6.1 and E3905.6.2 for the support of a luminaire that is the same size and weight. [314.27(D)]

Exception: Utilization equipment weighing not more than 6 pounds (2.7 kg) shall be permitted to be supported on other boxes or plaster rings that are secured to other boxes, provided that the equipment or its supporting yoke is secured to the box with not fewer than two No. 6 or larger screws. [314.27(D) Exception]
Conduit bodies and junction, pull and outlet boxes shall be installed so that the wiring therein can be accessed without removing any part of the building or structure or, in underground circuits, without excavating sidewalks, paving, earth or other substance used to establish the finished grade. (314.29)

Exception: Boxes covered by gravel, light aggregate or noncohesive granulated soil shall be listed for the application, and the box locations shall be effectively identified and access shall be provided for excavation. (314.29 Exception)
In damp or wet locations, boxes, conduit bodies and fittings shall be placed or equipped so as to prevent moisture from entering or accumulating within the box, conduit body or fitting. Boxes, conduit bodies and fittings installed in wet locations shall be listed for use in wet locations. Where drainage openings are installed in the field in boxes or conduit bodies listed for use in damp or wet locations, such openings shall be approved and not larger than 1/4 inch (6.4 mm). For listed drain fittings, larger openings are permitted where installed in the field in accordance with the manufacturer's instructions. (314.15)
Boxes and conduit bodies shall be of an approved size to provide free space for all enclosed conductors. In no case shall the volume of the box, as calculated in Section E3905.12.1, be less than the box fill calculation as calculated in Section E3905.12.2. The minimum volume for conduit bodies shall be as calculated in Section E3905.12.3. The provisions of this section shall not apply to terminal housings supplied with motors or generators. (314.16)
The volume of a wiring enclosure (box) shall be the total volume of the assembled sections, and, where used, the space provided by plaster rings, domed covers, extension rings, etc., that are marked with their volume in cubic inches or are made from boxes the dimensions of which are listed in Table E3905.12.1. [314.16(A)]

TABLE E3905.12.1 [Table 314.16(A)] MAXIMUM NUMBER OF CONDUCTORS IN METAL BOXESa

BOX DIMENSIONS
(inches trade size and type)
MAXIMUM CAPACITY
(cubic inches)
MAXIMUM NUMBER OF CONDUCTORSa
18 Awg 16 Awg 14 Awg 12 Awg 10 Awg 8 Awg 6 Awg
4 × 11/4 round or octagonal 12.5 8 7 6 5 5 4 2
4 × 11/2 round or octagonal 15.5 10 8 7 6 6 5 3
4 × 21/8 round or octagonal 21.5 14 12 10 9 8 7 4
4 × 11/4 square 18.0 12 10 9 8 7 6 3
4 × 11/2 square 21.0 14 12 10 9 8 7 4
4 × 21/8 square 30.3 20 17 15 13 12 10 6
411/16 × 11/4 square 25.5 17 14 12 11 10 8 5
411/16 × 11/2 square 29.5 19 16 14 13 11 9 5
411/16 × 21/8 square 42.0 28 24 21 18 16 14 8
3 × 2 × 11/2 device 7.5 5 4 3 3 3 2 1
3 × 2 × 2 device 10.0 6 5 5 4 4 3 2
3 × 2 × 21/4 device 10.5 7 6 5 4 4 3 2
3 × 2 × 21/2 device 12.5 8 7 6 5 5 4 2
3 × 2 × 23/4 device 14.0 9 8 7 6 5 4 2
3 × 2 × 31/2 device 18.0 12 10 9 8 7 6 3
4 × 21/8 × 11/2 device 10.3 6 5 5 4 4 3 2
4 × 21/8 × 17/8 device 13.0 8 7 6 5 5 4 2
4 × 21/8 × 21/8 device 14.5 9 8 7 6 5 4 2
33/4 × 2 × 21/2 masonry box/gang 14.0 9 8 7 6 5 4 2
33/4 × 2 × 31/2 masonry box/gang 21.0 14 12 10 9 8 7 4

For SI: 1 inch = 25.4 mm, 1 cubic inch = 16.4 cm3.
a. Where volume allowances are not required by Sections E3905.12.2.2 through E3905.12.2.5.
The volumes of standard boxes that are not marked with a cubic-inch capacity shall be as given in Table E3905.12.1. [314.16(A)(1)]
Boxes 100 cubic inches (1640 cm3) or less, other than those described in Table E3905.12.1, and nonmetallic boxes shall be durably and legibly marked by the manufacturer with their cubic-inch capacity. Boxes described in Table E3905.12.1 that have a larger cubic inch capacity than is designated in the table shall be permitted to have their cubic-inch capacity marked as required by this section. [314.16(A)(2)]
The volumes in Section E3905.12.2.1 through Section E3905.12.2.5, as applicable, shall be added together. No allowance shall be required for small fittings such as locknuts and bushings. [314.16(B)]
Each conductor that originates outside the box and terminates or is spliced within the box shall be counted once, and each conductor that passes through the box without splice or termination shall be counted once. Each loop or coil of unbroken conductor having a length equal to or greater than twice that required for free conductors by Section E3406.11.3, shall be counted twice. The conductor fill, in cubic inches, shall be computed using Table E3905.12.2.1. A conductor, no part of which leaves the box, shall not be counted. [314.16(B)(1)]

Exception: An equipment grounding conductor or not more than four fixture wires smaller than No. 14, or both, shall be permitted to be omitted from the calculations where such conductors enter a box from a domed fixture or similar canopy and terminate within that box. [314.16(B)(1) Exception]

TABLE E3905.12.2.1 [Table 314.16(B)] VOLUME ALLOWANCE REQUIRED PER CONDUCTOR

SIZE OF CONDUCTOR FREE SPACE WITHIN BOX
FOR EACH CONDUCTOR
(cubic inches)
18 AWG 1.50
16 AWG 1.75
14 AWG 2.00
12 AWG 2.25
10 AWG 2.50
8 AWG 3.00
6 AWG 5.00

For SI: 1 cubic inch = 16.4 cm3.
Where one or more internal cable clamps, whether factory or field supplied, are present in the box, a single volume allowance in accordance with Table E3905.12.2.1 shall be made based on the largest conductor present in the box. An allowance shall not be required for a cable connector having its clamping mechanism outside of the box. A clamp assembly that incorporates a cable termination for the cable conductors shall be listed and marked for use with specific nonmetallic boxes. Conductors that originate within the clamp assembly shall be included in conductor fill calculations provided in Section E3905.12.2.1 as though they entered from outside of the box. The clamp assembly shall not require a fill allowance, but, the volume of the portion of the assembly that remains within the box after installation shall be excluded from the box volume as marked in accordance with Section E3905.12.1.2. [314.16(B)(2)]
Where one or more fixture studs or hickeys are present in the box, a single volume allowance in accordance with Table E3905.12.2.1 shall be made for each type of fitting based on the largest conductor present in the box. [314.16(B)(3)]
For each yoke or strap containing one or more devices or equipment, a double volume allowance in accordance with Table E3905.12.2.1 shall be made for each yoke or strap based on the largest conductor connected to a device(s) or equipment supported by that yoke or strap. For a device or utilization equipment that is wider than a single 2-inch (51 mm) device box as described in Table E3905.12.1, a double volume allowance shall be made for each ganged portion required for mounting of the device or equipment. [314.16(B)(4)]
Where one or more equipment grounding conductors or equipment bonding jumpers enters a box, a single volume allowance in accordance with Table E3905.12.2.1 shall be made based on the largest equipment grounding conductor or equipment bonding jumper present in the box. [314.16(B)(5)]
Conduit bodies enclosing 6 AWG conductors or smaller, other than short-radius conduit bodies, shall have a cross-sectional area not less than twice the cross-sectional area of the largest conduit or tubing to which they can be attached. The maximum number of conductors permitted shall be the maximum number permitted by Section E3904.6 for the conduit to which it is attached. [314.16(C)(1)]
Only those conduit bodies that are durably and legibly marked by the manufacturer with their cubic inch capacity shall be permitted to contain splices, taps or devices. The maximum number of conductors shall be calculated using the same procedure for similar conductors in other than standard boxes. [314.16(C)(2)]
Conduit bodies such as capped elbows and service-entrance elbows that enclose conductors 6 AWG or smaller and that are only intended to enable the installation of the raceway and the contained conductors, shall not contain splices, taps, or devices and shall be of sufficient size to provide free space for all conductors enclosed in the conduit body. [314.16(C)(3)]
Conductors entering boxes, conduit bodies or fittings shall be protected from abrasion. (314.17)
Where raceways contain 4 AWG or larger insulated circuit conductors and these conductors enter a cabinet, box enclosure, or raceway, the conductors shall be protected by an identified fitting providing a smoothly rounded insulating surface, unless the conductors are separated from the fitting or raceway by identified insulating material securely fastened in place. [300.4(G)]

Exception: Where threaded hubs or bosses that are an integral part of a cabinet, box enclosure, or raceway provide a smoothly rounded or flared entry for conductors. [300.4(G) Exception]

Conduit bushings constructed wholly of insulating material shall not be used to secure a fitting or raceway. The insulating fitting or insulating material shall have a temperature rating not less than the insulation temperature rating of the installed conductors. [330.4(G)]
Openings through which conductors enter shall be closed in an approved manner. [314.17(A)]
Where raceway or cable is installed with metal boxes, or conduit bodies, the raceway or cable shall be secured to such boxes and conduit bodies. [314.17(B)]
Unused openings other than those intended for the operation of equipment, those intended for mounting purposes, or those permitted as part of the design for listed equipment, shall be closed to afford protection substantially equivalent to that of the wall of the equipment. Metal plugs or plates used with nonmetallic boxes or conduit bodies shall be recessed at least 1/4 inch (6.4 mm) from the outer surface of the box or conduit body. [110.12(A)]
In walls or ceilings of concrete, tile or other noncombustible material, boxes employing a flush-type cover or faceplate shall be installed so that the front edge of the box, plaster ring, extension ring, or listed extender will not be set back from the finished surface more than 1/4 inch (6.4 mm). In walls and ceilings constructed of wood or other combustible material, boxes, plaster rings, extension rings and listed extenders shall be flush with the finished surface or project therefrom. (314.20)
Openings in noncombustible surfaces that accommodate boxes employing a flush-type cover or faceplate shall be made so that there are no gaps or open spaces greater than 1/8 inch (3.2 mm) around the edge of the box. (314.21)
Surface extensions shall be made by mounting and mechanically securing an extension ring over the box. (314.22)

Exception: A surface extension shall be permitted to be made from the cover of a flush-mounted box where the cover is designed so it is unlikely to fall off, or be removed if its securing means becomes loose. The wiring method shall be flexible for an approved length that permits removal of the cover and provides access to the box interior and shall be arranged so that any bonding or grounding continuity is independent of the connection between the box and cover. (314.22 Exception)
Boxes and enclosures shall be supported in accordance with one or more of the provisions in Sections E3906.8.1 through E3906.8.6. (314.23)
An enclosure mounted on a building or other surface shall be rigidly and securely fastened in place. If the surface does not provide rigid and secure support, additional support in accordance with other provisions of Section E3906.8 shall be provided. [314.23(A)]
An enclosure supported from a structural member or from grade shall be rigidly supported either directly, or by using a metal, polymeric or wood brace. [314.23(B)]
Nails and screws, where used as a fastening means, shall be attached by using brackets on the outside of the enclosure, or they shall pass through the interior within 1/4 inch (6.4 mm) of the back or ends of the enclosure. Screws shall not be permitted to pass through the box except where exposed threads in the box are protected by an approved means to avoid abrasion of conductor insulation. [314.23(B)(1)]
Metal braces shall be protected against corrosion and formed from metal that is not less than 0.020 inch (0.508 mm) thick uncoated. Wood braces shall have a cross section not less than nominal 1 inch by 2 inches (25.4 mm by 51 mm). Wood braces in wet locations shall be treated for the conditions. Polymeric braces shall be identified as being suitable for the use. [314.23(B)(2)]
An enclosure mounted in a finished surface shall be rigidly secured there to by clamps, anchors, or fittings identified for the application. [314.23(C)]
An enclosure that does not contain a device(s), other than splicing devices, or support a luminaire, lampholder or other equipment, and that is supported by entering raceways shall not exceed 100 cubic inches (1640 cm3) in size. The enclosure shall have threaded entries or identified hubs. The enclosure shall be supported by two or more conduits threaded wrenchtight into the enclosure or hubs. Each conduit shall be secured within 3 feet (914 mm) of the enclosure, or within 18 inches (457 mm) of the enclosure if all entries are on the same side of the enclosure. [314.23(E)]

Exception: Rigid metal, intermediate metal, or rigid polyvinyl chloride nonmetallic conduit or electrical metallic tubing shall be permitted to support a conduit body of any size, provided that the conduit body is not larger in trade size than the largest trade size of the supporting conduit or electrical metallic tubing. [314.23(E) Exception]
An enclosure that contains a device(s), other than splicing devices, or supports a luminaire, lampholder or other equipment and is supported by entering raceways shall not exceed 100 cubic inches (1640 cm3) in size. The enclosure shall have threaded entries or identified hubs. The enclosure shall be supported by two or more conduits threaded wrench-tight into the enclosure or hubs. Each conduit shall be secured within 18 inches (457 mm) of the enclosure. [314.23(F)]

Exceptions:

1. Rigid metal or intermediate metal conduit shall be permitted to support a conduit body of any size, provided that the conduit bodies are not larger in trade size than the largest trade size of the supporting conduit. [314.23(F) Exception No. 1]

2. An unbroken length(s) of rigid or intermediate metal conduit shall be permitted to support a box used for luminaire or lampholder support, or to support a wiring enclosure that is an integral part of a luminaire and used in lieu of a box in accordance with Section E3905.1.1, where all of the following conditions are met:

2.1. The conduit is securely fastened at a point so that the length of conduit beyond the last point of conduit support does not exceed 3 feet (914 mm).

2.2. The unbroken conduit length before the last point of conduit support is 12 inches (305 mm) or greater, and that portion of the conduit is securely fastened at some point not less than 12 inches (305 mm) from its last point of support.

2.3. Where accessible to unqualified persons, the luminaire or lampholder, measured to its lowest point, is not less than 8 feet (2438 mm) above grade or standing area and at least 3 feet (914 mm) measured horizontally to the 8-foot (2438 mm) elevation from windows, doors, porches, fire escapes, or similar locations.

2.4. A luminaire supported by a single conduit does not exceed 12 inches (305 mm) in any direction from the point of conduit entry.

2.5. The weight supported by any single conduit does not exceed 20 pounds (9.1 kg).

2.6. At the luminaire or lampholder end, the conduit(s) is threaded wrenchtight into the box, conduit body, or integral wiring enclosure, or into hubs identified for the purpose. Where a box or conduit body is used for support, the luminaire shall be secured directly to the box or conduit body, or through a threaded conduit nipple not over 3 inches (76 mm) long. [314.23(F) Exception No. 2]
An enclosure supported by embedment shall be identified as being suitably protected from corrosion and shall be securely embedded in concrete or masonry. [314.23(G)]
Outlet boxes shall be effectively closed with a cover, faceplate or fixture canopy. Screws used for the purpose of attaching covers, or other equipment to the box shall be either machine screws matching the thread gauge or size that is integral to the box or shall be in accordance with the manufacturer's instructions. (314.25)
Covers and plates shall be nonmetallic or metal. Metal covers and plates shall be grounded. [314.25(A)]
Combustible wall or ceiling finish exposed between the edge of a fixture canopy or pan and the outlet box shall be covered with noncombustible material where required by Section E4004.2. [314.25(B)]
Where the wiring space of enclosures for switches or overcurrent devices contains conductors that are feeding through, spliced, or tapping off to other enclosures, switches, or overcurrent devices, all of the following conditions shall apply:

1. The total area of all conductors installed at any cross section of the wiring space shall not exceed 40 percent of the cross-sectional area of that space.

2. The total area of all conductors, splices, and taps installed at any cross section of the wiring space shall not exceed 75 percent of the cross-sectional area of that space.

3. A warning label shall be applied to the enclosure that identifies the closest disconnecting means for any feed-through conductors. (312.8)
In damp or wet locations, cabinets and panelboards of the surface type shall be placed or equipped so as to prevent moisture or water from entering and accumulating within the cabinet, and shall be mounted to provide an air-space not less than 1/4 inch (6.4 mm) between the enclosure and the wall or other supporting surface. Cabinets installed in wet locations shall be weatherproof. For enclosures in wet locations, raceways and cables entering above the level of uninsulated live parts shall be installed with fittings listed for wet locations. (312.2)

Exception: Nonmetallic enclosures installed on concrete, masonry, tile, or similar surfaces shall not be required to be installed with an air space between the enclosure and the wall or supporting surface. (312.2 Exception)
In walls of concrete, tile or other noncombustible material, cabinets and panelboards shall be installed so that the front edge of the cabinet will not set back of the finished surface more than 1/4 inch (6.4 mm). In walls constructed of wood or other combustible material, cabinets shall be flush with the finished surface or shall project therefrom. (312.3)
Noncombustible surfaces that are broken or incomplete shall be repaired so that there will not be gaps or open spaces greater than 1/8 inch (3.2 mm) at the edge of the cabinet or cutout box employing a flush-type cover. (312.4)
Unused openings, other than those intended for the operation of equipment, those intended for mounting purposes, and those permitted as part of the design for listed equipment, shall be closed to afford protection substantially equivalent to that of the wall of the equipment. Metal plugs and plates used with nonmetallic cabinets shall be recessed at least 1/4 inch (6.4 mm) from the outer surface. Unused openings for circuit breakers and switches shall be closed using identified closures, or other approved means that provide protection substantially equivalent to the wall of the enclosure. (110.12(A)]
Conductors entering cabinets and panelboards shall be protected from abrasion and shall comply with Section E3906.1.1. (312.5)
Openings through which conductors enter cabinets, panelboards and meter sockets shall be closed in an approved manner. [312.5(A)]
Where cables are used, each cable shall be secured to the cabinet, panelboard, cutout box, or meter socket enclosure. [312.5(C)]

Exception: Cables with entirely nonmetallic sheaths shall be permitted to enter the top of a surface-mounted enclosure through one or more sections of rigid raceway not less than 18 inches (457 mm) nor more than 10 feet (3048 mm) in length, provided all the following conditions are met:

1. Each cable is fastened within 12 inches (305 mm), measured along the sheath, of the outer end of the raceway.

2. The raceway extends directly above the enclosure and does not penetrate a structural ceiling.

3. A fitting is provided on each end of the raceway to protect the cable(s) from abrasion and the fittings remain accessible after installation.

4. The raceway is sealed or plugged at the outer end using approved means so as to prevent access to the enclosure through the raceway.

5. The cable sheath is continuous through the raceway and extends into the enclosure beyond the fitting not less than 1/4 inch (6.4 mm).

6. The raceway is fastened at its outer end and at other points in accordance with Section E3802.1.

7. The allowable cable fill shall not exceed that permitted by Table E3907.8. A multiconductor cable having two or more conductors shall be treated as a single conductor for calculating the percentage of conduit fill area. For cables that have elliptical cross sections, the cross-sectional area calculation shall be based on the major diameter of the ellipse as a circle diameter. [312.5(C) Exception]

TABLE E3907.8 (Chapter 9, Table 1) PERCENT OF CROSS SECTION OF CONDUIT AND TUBING FOR CONDUCTORS

NUMBER OF
CONDUCTORS
MAXIMUM PERCENT OF CONDUIT AND
TUBING AREA FILLED BY CONDUCTORS
1 53
2 31
Over 2 40
Wire-bending space within an enclosure containing a panelboard shall comply with the requirements of Sections E3907.9.1 through E3907.9.3.
The top and bottom wire-bending space for a panelboard enclosure shall be sized in accordance with Table E3907.9.1(1) based on the largest conductor entering or leaving the enclosure. [408.55 (A)]

Exceptions:

1. For a panelboard rated at 225 amperes or less and designed to contain not more than 42 overcurrent devices, either the top or bottom wire-bending space shall be permitted to be sized in accordance with Table E3907.9.1(2). For the purposes of this exception, a 2-pole or a 3-pole circuit breaker shall be considered as two or three overcurrent devices, respectively. [408.55(A) Exception No. 1]

2. For any panelboard, either the top or bottom wire-bending space shall be permitted to be sized in accordance with Table E3907.9.1(2) where the wire-bending space on at least one side is sized in accordance with Table E3907.9.1(1) based on the largest conductor to be terminated in any side wire-bending space. [408.55(A) Exception No. 2]

3. Where the panelboard is designed and constructed for wiring using only a single 90-degree bend for each conductor, including the grounded circuit conductor, and the wiring diagram indicates and specifies the method of wiring that must be used, the top and bottom wire-bending space shall be permitted to be sized in accordance with Table E3907.9.1(2). [408.55(A) Exception No. 3]

4. Where there are no conductors terminated in that space, either the top or the bottom wire-bending space, shall be permitted to be sized in accordance with Table E3907.9.1(2). [408.55(A) Exception No. 4]

TABLE E3907.9.1(1) [Table 312.6(B)] MINIMUM WIRE-BENDING SPACE AT TERMINALS (see note 1)

WIRE SIZE
(AWG or kcmil)
WIRES PER TERMINAL
All other conductors Compact stranded AA-8000
aluminum alloy conductors
(see Note 3)
One (see note 2) Two
inches mm inches mm
14-10 12-8 Not specified Not specified
8 6 11/2 38.1
6 4 2 50.8
4 2 3 76.2
3 1 3 76.2
2 1/0 31/2 88.9
1 2/0 41/2 114
1/0 3/0 51/2 140 51/2 140
2/0 4/0 6 152 6 152
3/0 250 61/2a 165a 61/2a 165a
4/0 300 7b 178b 71/2c 190c
250 350 81/2d 216d 81/2d 229d
300 400 10c 254c 10d 254d
350 500 12c 305c 12c 305c
400 600 13c 330c 13c 330c
500 700-750 14c 356c 14c 356c
600 800-900 15c 381c 16c 406c
700 1000 16c 406c 18c 457c

1. Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector in a direction perpendicular to the enclosure wall.
2. For removable and lay-in wire terminals intended for only one wire, bending space shall be permitted to be reduced by the following number of millimeters (inches):
a. 1/2 inches (12.7 mm)
b. 1 inches (25.4 mm)
c. 11/2 inches (38.1 mm)
d. 2 inches (50.8 mm)
3. This column shall be permitted to determine the required wire-bending space for compact stranded aluminum conductors in sizes up to 1000 kcmil and manufactured using AA-8000 series electrical grade aluminum alloy conductor material.


TABLE E3907.9.1(2) [Table 312.6(A)] MINIMUM WIRE-BENDING SPACE AT TERMINALS AND MINIMUM WIDTH OF WIRING GUTTERS (see note 1)

WIRE SIZE
(AWG or kcmil)
WIRES PER TERMINAL
One Two
inches mm inches mm
14-10 Not
specified
Not
specified
8-6 11/2 38.1
4-3 2 50.8
2 21/2 63.5
1 2 76.2
1/0-2/0 31/2 88.9 5 127
3/0-4/0 4 102 6 152
250 41/2 114 6 152
300-350 5 127 8 203
400-500 6 152 8 203
600-700 8 203 10 254

1. Bending space at terminals shall be measured in a straight line from the end of the lug or wire connector in the direction that the wire leaves the terminal to the wall, barrier, or obstruction.
Side wire-bending space shall be in accordance with Table E3907.9.1(2) based on the largest conductor to be terminated in that space. [408.55(B)]
The distance between the center of the rear entry and the nearest termination for the entering conductors shall be not less than the distance given in Table E3907.9.1(1). Where a raceway or cable entry is in the wall of the enclosure, opposite a removable cover, the distance from that wall to the cover shall be permitted to comply with the distance required in Table E3907.9.1(2). [408.55 (C)]
Metal enclosures of conductors, devices and equipment shall be connected to the equipment grounding conductor. (250.86)

Exceptions:

1. Short sections of metal enclosures or raceways used to provide cable assemblies with support or protection against physical damage. (250.86 Exception No. 2)

2. A metal elbow that is installed in an underground installation of rigid nonmetallic conduit and is isolated from possible contact by a minimum cover of 18 inches (457 mm) to any part of the elbow or that is encased in not less than 2 inches (51 mm) of concrete. (250.86 Exception No. 3)
Exposed, normally noncurrent-carrying metal parts of fixed equipment supplied by or enclosing conductors or components that are likely to become energized shall be connected to the equipment grounding conductor where any of the following conditions apply:

1. Where within 8 feet (2438 mm) vertically or 5 feet (1524 mm) horizontally of earth or grounded metal objects and subject to contact by persons;

2. Where located in a wet or damp location and not isolated; or

3. Where in electrical contact with metal. (250.110)
Exposed, normally noncurrent-carrying metal parts of the following equipment and enclosures shall be connected to an equipment grounding conductor:

1. Luminaires as provided in Chapter 40. [250.112(J)]

2. Motor-operated water pumps, including submersible types.Where a submersible pump is used in a metal well casing, the well casing shall be connected to the pump circuit equipment grounding conductor. [250.112(L)]
Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. Such circuit shall be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault might occur to the electrical supply source. [250.(A)(5)]
The earth shall not be considered as an effective ground-fault current path. [250.4(A)(5)]
A grounded conductor shall not be connected to normally noncurrent-carrying metal parts of equipment, to equipment grounding conductor(s), or be reconnected to ground on the load side of the service disconnecting means. [250.24(A)(5)]
A grounded circuit conductor shall not be used for grounding noncurrent-carrying metal parts of equipment on the load side of the service disconnecting means. [250.142(B)]
The equipment grounding conductor run with or enclosing the circuit conductors shall be one or more or a combination of the following:

1. A copper, aluminum or copper-clad conductor.This conductor shall be solid or stranded; insulated, covered or bare; and in the form of a wire or a busbar of any shape. [250.118(1)]

2. Rigid metal conduit. [250.118(2)]

3. Intermediate metal conduit. [250.118(3)]

4. Electrical metallic tubing. [250.118(4)]

5. Armor of Type AC cable in accordance with Section E3908.4. [250.118(8)]

6. Type MC cable that provides an effective ground-fault current path in accordance with one or more of the following:

6.1. It contains an insulated or uninsulated equipment grounding conductor in compliance with Item 1 of this section.

6.2. The combined metallic sheath and uninsulated equipment grounding/bonding conductor of interlocked metal tape-type MC cable that is listed and identified as an equipment grounding conductor.

6.3. The metallic sheath or the combined metallic sheath and equipment grounding conductors of the smooth or corrugated tube-type MC cable that is listed and identified as an equipment grounding conductor. [250.118(10)]

7. Other electrically continuous metal raceways and auxiliary gutters. [250.118(13)]

8. Surface metal raceways listed for grounding. [250.118(14)]
Flexible metal conduit shall be permitted as an equipment grounding conductor where all of the following conditions are met:

1. The conduit is terminated in listed fittings.

2. The circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less.

3. The combined length of flexible metal conduit and flexible metallic tubing and liquid-tight flexible metal conduit in the same ground return path does not exceed 6 feet (1829 mm).

If used to connect equipment where flexibility is necessary to minimize the transmission of vibration from equipment or to provide flexibility for equipment that requires movement after installation, an equipment grounding conductor shall be installed. [250.118(5)]
Liquid-tight flexible metal conduit shall be permitted as an equipment grounding conductor where all of the following conditions are met:

1. The conduit is terminated in listed fittings.

2. For trade sizes 3/8 through 1/2 (metric designator 12 through 16), the circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less.

3. For trade sizes 3/4 through 11/4 (metric designator 21 through 35), the circuit conductors contained in the conduit are protected by overcurrent devices rated at not more than 60 amperes and there is no flexible metal conduit, flexible metallic tubing, or liquid-tight flexible metal conduit in trade sizes 3/8 inch or 1/2 inch (9.5 mm through 12.7 mm) in the ground fault current path.

4. The combined length of flexible metal conduit and flexible metallic tubing and liquid-tight flexible metal conduit in the same ground return path does not exceed 6 feet (1829 mm).

If used to connect equipment where flexibility is necessary to minimize the transmission of vibration from equipment or to provide flexibility for equipment that requires movement after installation, an equipment grounding conductor shall be installed. [250.118(6)]
In addition to the insulated conductors, the cable shall have an insulated, covered, or bare equipment grounding conductor. Equipment grounding conductors shall be sized in accordance with Table E3908.12. (334.108)
Noncurrent-carrying metal parts of equipment, raceways and other enclosures, where required to be grounded, shall be grounded by one of the following methods: (250.134)

1. By any of the equipment grounding conductors permitted by Sections E3908.8 through E3908.8.3. [250.134(A)]

2. By an equipment grounding conductor contained within the same raceway, cable or cord, or otherwise run with the circuit conductors. Equipment grounding conductors shall be identified in accordance with Section E3407.2. [250.134(B)]
Fixtures and equipment shall be considered grounded where mechanically connected to an equipment grounding conductor as specified in Sections E3908.8 through E3908.8.3. Wire type equipment grounding conductors shall be sized in accordance with Section E3908.12. (250 Part VII)
Where an equipment grounding conductor consists of a raceway, cable armor or cable sheath or where such conductor is a wire within a raceway or cable, it shall be installed in accordance with the provisions of this chapter and Chapters 34 and 38 using fittings for joints and terminations approved for installation with the type of raceway or cable used. All connections, joints and fittings shall be made tight using suitable tools. (250.120)
Copper, aluminum and copper-clad aluminum equipment grounding conductors of the wire type shall be not smaller than shown in Table E3908.12, but they shall not be required to be larger than the circuit conductors supplying the equipment. Where a raceway or a cable armor or sheath is used as the equipment grounding conductor, as provided in Section E3908.8, it shall comply with Section E3908.4. Where ungrounded conductors are increased in size from the minimum size that has sufficient ampacity for the intended installation, wire type equipment grounding conductors shall be increased proportionally according to the circular mil area of the ungrounded conductors. [250.122(A) and (B)]

TABLE E3908.12 (Table 250.122) EQUIPMENT GROUNDING CONDUCTOR SIZING

RATING OR SETTING OF AUTOMATIC OVERCURRENT DEVICE IN CIRCUIT AHEAD OF
EQUIPMENT, CONDUIT, ETC., NOT EXCEEDING THE FOLLOWING RATINGS (amperes)
MINIMUM SIZE
Copper wire No. (AWG) Aluminum or copper-clad
aluminum wire No. (AWG)
15 14 12
20 12 10
60 10 8
100 8 6
200 6 4
300 4 2
400 3 1
Where a single equipment grounding conductor is run with multiple circuits in the same raceway or cable, it shall be sized for the largest overcurrent device protecting conductors in the raceway or cable. [250.122(C)]
Where circuit conductors are spliced within a box or terminated on equipment within or supported by a box, any equipment grounding conductors associated with the circuit conductors shall be connected within the box or to the box with devices suitable for the use. Connections depending solely on solder shall not be used. Splices shall be made in accordance with Section E3406.10 except that insulation shall not be required. The arrangement of grounding connections shall be such that the disconnection or removal of a receptacle, luminaire or other device fed from the box will not interfere with or interrupt the grounding continuity. [250.146(A) and (C)]
An equipment bonding jumper, sized in accordance with Table E3908.12 based on the rating of the overcurrent device protecting the circuit conductors, shall be used to connect the grounding terminal of a grounding-type receptacle to a grounded box except where grounded in accordance with one of the following: (250.146)

1. Surface mounted box.Where the box is mounted on the surface, direct metal-to-metal contact between the device yoke and the box shall be permitted to ground the receptacle to the box. At least one of the insulating washers shall be removed from receptacles that do not have a contact yoke or device designed and listed to be used in conjunction with the supporting screws to establish the grounding circuit between the device yoke and flush-type boxes. This provision shall not apply to cover-mounted receptacles except where the box and cover combination are listed as providing satisfactory ground continuity between the box and the receptacle. A listed exposed work cover shall be considered to be the grounding and bonding means where the device is attached to the cover with at least two fasteners that are permanent, such as a rivet or have a thread locking or screw locking means and where the cover mounting holes are located on a flat non-raised portion of the cover. [250.146(A)]

2. Contact devices or yokes. Contact devices or yokes designed and listed for the purpose shall be permitted in conjunction with the supporting screws to establish equipment bonding between the device yoke and flush-type boxes. [250.146(B)]

3. Floor boxes.The receptacle is installed in a floor box designed for and listed as providing satisfactory ground continuity between the box and the device. [250.146(C)]
A connection shall be made between the one or more equipment grounding conductors and a metal box by means of a grounding screw that shall be used for no other purpose, equipment listed for grounding or by means of a listed grounding device. Where screws are used to connect grounding conductors or connection devices to boxes, such screws shall be one or more of the following: [250.148(C)]

1. Machine screw-type fasteners that engage not less than two threads.

2. Machine screw-type fasteners that are secured with a nut.

3. Thread-forming machine screws that engage not less than two threads in the enclosure. [250.8(5) and (6)]
One or more equipment grounding conductors brought into a nonmetallic outlet box shall be arranged to allow connection to fittings or devices installed in that box. [250.148(D)]
Nonconductive coatings such as paint, lacquer and enamel on equipment to be grounded shall be removed from threads and other contact surfaces to ensure electrical continuity or the equipment shall be connected by means of fittings designed so as to make such removal unnecessary. (250.12)
Metal raceways, cable armor, cable sheath, enclosures, frames, fittings and other metal noncurrent-carrying parts that serve as equipment grounding conductors, with or without the use of supplementary equipment grounding conductors, shall be effectively bonded where necessary to ensure electrical continuity and the capacity to conduct safely any fault current likely to be imposed on them. Any nonconductive paint, enamel and similar coating shall be removed at threads, contact points and contact surfaces, or connections shall be made by means of fittings designed so as to make such removal unnecessary. [250.96(A)]
The equipment bonding jumper on the load side of an overcurrent devices shall be sized, as a minimum, in accordance with Table E3908.12, but shall not be required to be larger than the circuit conductors supplying the equipment. An equipment bonding conductor shall be not smaller than No. 14 AWG.

A single common continuous equipment bonding jumper shall be permitted to connect two or more raceways or cables where the bonding jumper is sized in accordance with Table E3908.12 for the largest overcurrent device supplying circuits therein. [250.102(D) and 250.122]
Bonding jumpers or conductors and equipment bonding jumpers shall be installed either inside or outside of a raceway or an enclosure in accordance with Sections E3908.20.1 and E3908.20.2. [250.102(E)]
Where installed inside a raceway or enclosure, equipment bonding jumpers and bonding jumpers or conductors shall comply with the requirements of Sections E3407.2 and E3908.13. [250.102(E)(1)]
Where installed outside of a raceway or enclosure, the length of the bonding jumper or conductor or equipment bonding jumper shall not exceed 6 feet (1829 mm) and shall be routed with the raceway or enclosure. [250.102(E)(2)]

Equipment bonding jumpers and supply-side bonding jumpers installed for bonding grounding electrodes and installed at outdoor pole locations for the purpose of bonding or grounding isolated sections of metal raceways or elbows installed in exposed risers of metal conduit or other metal raceway, shall not be limited in length and shall not be required to be routed with a raceway or enclosure. [250.102(E)(2) Exception]
Bonding jumpers or conductors and equipment bonding jumpers shall be installed in accordance with Section E3610.2. [250.102(E)(3)]
Flexible cords shall be used only for the connection of appliances where the fastening means and mechanical connections of such appliances are designed to permit ready removal for maintenance, repair or frequent interchange and the appliance is listed for flexible cord connection. Flexible cords shall not be installed as a substitute for the fixed wiring of a structure; shall not be run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings or floors; shall not be concealed behind walls, floors, ceilings or located above suspended or dropped ceilings. (400.7 and 400.8)
The ampere load of flexible cords serving fixed appliances shall be in accordance with Table E3909.2. This table shall be used in conjunction with applicable end use product standards to ensure selection of the proper size and type. Where flexible cord is approved for and used with a specific listed appliance, it shall be considered to be protected where applied within the appliance listing requirements. [240.4, 240.5(A), 240.5(B)(1), 400.5, and 400.13]

TABLE E3909.2 [Table 400.5(A)(1)] MAXIMUM AMPERE LOAD FOR FLEXIBLE CORDS

CORD SIZE
(AWG)
CORD TYPES S, SE, SEO, SJ, SJE, SJEO, SJO, SJOO,
SJT, SJTO, SJTOO, SO, SOO, SRD, SRDE, SRDT, ST,
STD, SV, SVO, SVOO, SVTO, SVTOO
Maximum ampere load
Three current-carrying
conductors
Two current-carrying
conductors
18 7 10
16 10 13
14 15 18
12 20 25
Flexible cord shall be used only in continuous lengths without splices or taps. (400.9)
Where used in accordance with Section E3909.1, each flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet. [400.7(B)]
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