Above Ground Wiring Installation

NM, UF, AC, and MC Cable Installation
1. Use NM, UF, AC, and MC cable where the cable is not subject to physical damage. Physical damage can occur unless the cable is covered by drywall or by other material or unless the cable is run in conduit or tubing. Physical damage includes damage by sunlight.
2. Protect NM, UF, AC, and MC cable using RMC, IMC, EMT, or Schedule 80 RNC when the cable is subject to physical damage. Extend the protection at least (≥) 6 inches above the floor when the cable runs through the floor. This provision applies to all exposed wall framing, such as unfinished basements and garages, to cable that runs through framed and concrete slab floors, and to cable run outdoors. See also specific requirements described in subsequent sections for cables run in attics, crawl spaces, and basements.
3. Protect NM, UF, AC, and MC cable using nail guards or other approved physical protection when the cable is installed:
(a) through holes, notches, or grooves that are closer than (<) 1 ¼ inches to the edge of a stud or joist, and
(b) in notches and grooves in places such as drywall, plaster and under carpet, unless the groove or notch is deeper than (≥) 1 ¼ inches, and
(c) through holes in metal framing (use grommets or bushings), and
(d) parallel to the edge of a stud, joist, or furring strip when the cable is closer than (<) 1 ¼ inches to the edge of the framing member.
4. Support NM, UF, AC, and MC cable every 4 ½ feet. Use wire staples or other approved fasteners to support vertical runs of NM, UF, AC, and MC cable. Staple the cable only on the flat edge. Note that wiring methods need not always be secured to be considered supported. Cable run across the tops of joists and truss chords is usually considered supported without being secured to the joists. Cable must be secured to be considered supported when it is run vertically and when it is run on the sides and bottoms of framing members.
5. Secure NM, UF, AC, and MC cable not more than (≤) 8 inches from boxes and terminations that do not have cable clamps. This includes most plastic boxes. Secure NM, UF, AC, and MC cable not more than (≤) 12 inches from boxes and terminations that have cable clamps. This includes most metal boxes. Measure the distance from where the cable sheathing ends in the box, not from the box itself.
6. Use NM and AC cable only in dry locations. Do not use NM and AC cable in conduit that is buried in the ground or in conduit installed in a wet location. Buried conduit and conduit installed in a wet location are considered wet locations.
7. You may use UF and MC cable in wet locations including outdoors and underground if it is not subject to damage.
8. Do not run NM, UF, AC, and MC cable inside concrete and inside solid or fully grouted masonry walls and floors.
9. Do not run NM and AC cable inside masonry cells when the cells are subject to dampness and
when they are below grade.
10. You may run NM, UF, AC, and MC cable inside masonry cells when the cells will remain dry.
11. Use sunlight resistant NM and UF cable if the cable is exposed to direct sunlight. This includes cable run in att ics under ventilation openings that might admit sunlight. You may protect the cable with sunlight resistant materials or enclose the cable in conduit.

Conduit and Tubing Installation
1. Apply the following installation requirements to EMT, IMC, RMC, ENT, FMC, LFC, and RNC:
(a) limit the number of 90 degree bends between junction boxes to not more than (≤) four, and
(b) install bushings where conduit or tubing enters a box, fitting, or enclosure, unless the device provides equivalent protection against damage to any wires that may be pulled into the device, and
(c) remove rough edges from the ends of all conduit and tubing that may damage wires, and
(d) support EMT, IMC, and RMC not more than (≤) every 10 feet and within (≤) 3 feet of junction boxes or terminations, and
(e) support ENT not more than (≤) every 3 feet, unless the ENT is in an accessible ceiling, such as a drop ceiling, and if the distance between light fixtures is not more than (≤) 6 feet, and
(f) support FMC and LFC not more than (≤) every 4 ½ feet and within 12 inches of junction boxes and terminations, unless the FMC and LFC is in an accessible ceiling, such as a drop ceiling, and if the distance between light fixtures is not more than (≤) 6 feet.
2. You may allow not more than (≤) 36 inches between the last support and a light fixture or other equipment that may need to be moved for service or replacement.

Wiring Support Requirements
1. The following table lists the on center support requirements for wiring methods. Note that some wiring methods have special requirements shown by the following superscripts: (1) support is not required in accessible ceilings, such as drop ceilings, if the distance between light fixtures is not more than (≤) 6 feet, (2) you may allow not more than (≤) 24 inches between the last support and a light fixture or other equipment that may need to be moved for service or replacement,
(3) you may allow not more than (≤) 36 inches between the last support and a light fixture or other equipment that may need to be moved for service or replacement, (4) support NM and UF cable not more than (≤) 8 inches from boxes and terminations that do not have cable clamps. This includes most plastic boxes. Measure the support distance from where the cable sheathing ends in the box, not from the box itself, (5) support NM and UF cable not more than (≤) 12 inches from boxes and terminations that have cable clamps. This includes most metal boxes. (6) support RNC not more than (≤) 5 feet for conduit sizes more than (>) one inch, (7) you may allow not more than (≤) 36 inches for conduit sizes ½ through 1 ¼ inches, not more than (≤) 48 inches for conduit sizes 1 ½ through 2 inches, and not more than (≤) 60 inches for conduit sizes 2 ½ and larger when flexibility is needed after installation.

Wiring Protection in Attics
1. Protect electrical cables in accessible attics by using substantial guard strips that are at least as
tall as the cables electrical cables when:
(a) access to the attic is by permanent stairs or ladder (such as a pull-down attic ladder) and the cables are within (≤) 7 feet vertically from the top of attic floor joists or truss bottom chords or the cables run across the face (shortest dimension) of rafters, studs, or truss webs or chords, or
(b) access to the attic is by scuttle hole or similar opening and the cables described are within (≤) 6 feet horizontally and 7 feet vertically from the nearest point of the attic access opening.
2. You need not protect electrical cables in accessible attics when the cables are installed:
(a) running parallel to the edge of the framing and at least (≥) 1 ¼ inches from the edge of the framing, or
(b) in holes that are at least (≥) 1 ¼ inches from the edge of the framing.

Wiring in Crawl Space and Unfinished Basement Joists
1. Install small gage cables: (a) parallel with joists and at least (≥) 1 ¼ inches from the bottom of joists, or (b) through holes drilled at least (≥) 1 ¼ inches from the bottom of joists. Do not install these cables directly along the bottom of joists, unless you install the cables on running boards. A running board is wood, such as a 1×6, attached to the bottom of the basement ceiling joists. This applies to cables containing wires #10 AWG and smaller.                                                                                                                                                   2. You may install cables containing at least (≥) two #6 AWG or larger wires or at least three #8 AWG or larger wires directly along the bottom of basement ceiling joists without additional protection.

Bends in Cables and Conduit
1. Do not bend cables, conduit, tubing, or other raceways if the bend damages the wiring method or if the bend reduces the diameter of the conduit, tubing, or other raceway.
2. Bend NM, UF, and SE cable so that the radius of the curve on the inner edge of the cable is not smaller than (<) 5 times the diameter of the cable. Example: if the cable is ½ inch wide, any bend in the cable should have a radius of not smaller than (<) 2 ½ inches.

Wiring Exposed to Direct Sunlight
1. Use cables and wires that are listed as sunlight resistant when they may be exposed to direct sunlight. You may cover wires and cables not listed as sunlight resistant with insulating tape or a sleeve that is listed as sunlight resistant.

Raceways and Cables Exposed to Different Temperatures
1. Seal conduit, tubing, cables, and sleeves against air movement if: (a) the assembly runs between a warm and moist area and a cool area, and if (b) condensation is known to be a problem. Use an approved material, such as electrical putt y, to seal the assembly against air movement. Examples of when this situation can occur include: (a) during the winter in cold climates when an assembly runs between warm conditioned space and cold unconditioned space such as an attic or crawl space, and (b) during the summer in warm climates when an assembly runs between warm unconditioned space and cool conditioned space. This situation is more likely to occur in metallic conduit and tubing.