Nm Wire Run Through Residential Attics

Any nm cables bundled together for more than 24 will require an ampacity adjustment.

Nm wire run through residential attics.

There should be no excess wire or ends left in the attic. Section 333 12 requires where run across the top of floor joists meaning the attic floor joists the cable shall be protected by substantial guard strips that are at least as high as the cable this is a performance requirement because you are not told how to do it just that you must do it. When i run low voltage wires parallel to line voltage wires i fasten the low voltage wires at least 6 in. Also if they re run in an attic space above the insulation then they would also be adjusted for the attic ambient temperature.

Snip all the white neutral wires to the same length 6 in. Away from the line voltage. The sheathing on nm cable really offers little in the way of protection against physical damage so it is approved for use only in situations where the cables are protected against damage including. Normally the cables carry 10 12 or 14 gauge conducting wires for individual house circuits.

In most cases the nm cable must closely follow the building surface or another means of support for the cable must be provided. It could be installed exposed in a residential garage or in an attic or basement. And low voltage are run parallel through the same hole. Once you are running the wire feed both ends of the wire through their corresponding holes and climb down from the attic.

Step 8 locate the wires at the sites where you fed them to from the attic and complete your connections first then secure or conceal the rest of the wire. Thursday february 13 2020 exposed nm nmc and nms cable are allowed to be run in one and two family dwellings their attached or detached garages and their storage buildings by the national electrical code nec 334 10 and 334 15. The extent of the interference depends on the quality of wire you use and the amount of current passing through the line voltage wires. Nm cable is simply a bundle of individual conducting wires wrapped in a plastic vinyl outer sheathing.