UL SUBJECT 504

Abstract

Scope: This Outline of Investigation covers mineral-insulated (Type MI) metal-sheathed cable, which consists of one or more solid copper conductors insulated with highly compressed magnesium oxide and enclosed in a continuous copper or alloy steel sheath, with or without a nonmetallic jacket. Cables rated 600 V may be composed of 16 AWG to 500 kcmil single conductor, 16 to 4 AWG two and three conductor, 16 to 6 AWG four conductor, and 16 to 10 AWG seven conductor constructions. Cables rated 300 V may be composed of two, three, four and seven conductor, sizes 18 to 16 AWG, for use on signaling circuits. The copper sheath is suitable as an equipment grounding conductor. For cable with alloy steel outer sheath one of the insulated conductors is to be used for equipment grounding. The cable shall be installed in accordance with Article 332 of National Electrical Code, NFPA 70