Installing Cables Through Wood and Metal Framing Members

Another method of installing cables is running them through holes drilled at the approximate center or (1 ¼ inches away from edge) of wooden beams or metal frames. Installation of 1/16 inch thick metal plates on beams or metal frames are required to protect from nails and screws in the following situations.

1. If it is not possible to drill hole at the minimum distance from edge, cables are ran through notches and are not protected by beam.
2. Cables ran parallel to studs, joists or rafter do not have a clearance of at least 1 ¼ inch
3. Nonmetallic-sheathed cable is laid on a grove and does not clear the 1 ¼ inch.

Bushings are also used for protecting nonmetallic-sheathed cable; they must be snapped into place before running the cable; however it is not necessary to install bushings when running them using armored cable.