In wiring installations, how is Type NM cable classified regarding its insulation?

Type NM cable, commonly known as non-metallic sheathed cable, is classified as general-purpose due to its broad application in residential and light commercial wiring. This classification indicates that Type NM cable is suitable for a variety of indoor environments and is often used for branch circuits in areas like living rooms, bedrooms, and kitchens. It is designed to be used behind walls, where it will be protected from physical damage, which makes it a versatile choice for electrical installations.

The insulation found within this type of cable is not specifically designed to resist water or fire to the extent that other specialized cables may be. Instead, the general-purpose designation means it may be adequate for normal conditions without specific resistance qualities to elements like moisture or extreme heat. This allows electricians to utilize Type NM cable in a wide range of typical wiring situations, making it a popular choice in residential construction.