Mineral Insulated Metal Sheathed Cable

A factory assembly of one or more conductors insulated with a highly compressed refractory mineral insulation and enclosed in a liquidtight and gastight continuous copper or alloy steel sheath.

Conductors: Type MI cable conductors shall be of solid copper, nickel, or nickel-coated copper with a resistance corresponding to standard AWG kcmil sizes.

Equipment Grounding Conductor: Where the outer sheath is made of copper, it shall provide an adequate path to serve as an equipment grounding conductor. Where the outer sheath is made of steel, a separate equipment grounding conductor shall be provided.

Insulation: The conductor insulation in Type MI cable shall be a highly compressed refractory mineral that provides proper spacing for all conductors.

Sheath: The outer sheath shall be of a continuous construction to provide mechanical protection and moisture seal.