What does "NM" in NM cable stand for?

The designation "NM" in NM cable stands for Non-Metallic. This type of cable is commonly used in residential wiring and is favored due to its insulation properties, which provide good protection against moisture and other environmental factors. NM cable is typically constructed with two or more insulated conductors and a ground wire, all covered by a non-metallic sheath, making it both lightweight and easy to handle.

The non-metallic sheath helps in preventing short circuits and makes the installation process safer, as it is less likely to conduct electricity compared to metal options. This is especially advantageous in typical home environments, where NM cable can be run in walls and ceilings without the added bulk or expense of metal raceways. Furthermore, NM cable is recognized by the National Electrical Code (NEC) for specific applications, which adds to its popularity in new construction and renovations.