Type Nm Cable Must Be Supported Within

General cable support.

Type nm cable must be supported within.

Section 1201 2 of the icc ec 2001 supplement modifies the nec 1999 provisions to allow type nm cable in 4 story apartment buildings. Section 338 10 b permits type se cable as branch circuits or feeders and contains multiple installation requirements. Nm cable must be supported and secured every 4 ft. Nm is normally used in one and two family dwellings and certain multifamily dwellings.

When used as a branch circuit or feeder type se cable must be supported and secured in accordance with 334 30 at intervals not exceeding 4 feet and within 1 foot of every outlet box junction box cabinet or fitting. They also must be secured within 12 inches of an electrical box that includes a cable clamp or within eight inches of a box or enclosure without a cable clamp. Although in article 314 17 c s exception nonmetallic boxes have no cable clamps and must have cables supported within eight inches of the junction box. The nm cable must be supported within not more than 4 feet of the fixture according to 334 30 b.

However if this accessible ceiling is an occupancy other than one and two family and multifamily dwellings 334 12 a 2 does not permit the use of exposed type nm cable. And within 12 inches of every outlet box junction box cabinet or fitting. Type mc cable of sizes 14 12 and 10 awg must be secured within 12 from every box and then must be supported at intervals not exceeding. Type nm cable may not be used in any building of four or more stories.

The most common type of nm used are 2 wire and 3 wire. When nonmetallic device boxes that are 2 gang or more are used the installed type nm cable must be supported no more than inches from the box 12 when using aluminum conductors size conductor must be used to carry the same amount of current as a copper conductor. These cable clamps are not to be removed. Nonmetallic sheathed cable shall be supported and secured by staples cable ties straps hangers or similar fittings designed and installed so as not to damage the cable at intervals not exceeding 1 4 m 4 ft and within 300 mm 12 in of every outlet box junction box cabinet or fitting.

Keep in mind that support does not always mean fastening the cable to framing. Runs of nm cable must be supported at least every 54 inches. Where nonmetallic cable is installed horizontally through holes or notches in framing members it is considered supported and not required to be secured. Nm b is what you will see when shopping for nm cable which is rated for 90 degrees c 194 degrees f.

6 the nec requires at least of free conductor in electrical device boxes for connection to switches and receptacles.