Frederic P Miller

Mineral-Insulated Copper-Clad Cable Frederic P Miller

Publisher Marketing: Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Mineral-insulated copper-clad cable is a variety of electrical cable made from copper conductors inside a copper sheath, insulated by inorganic magnesium oxide powder. The name is often abbreviated to MICC or MI cable, and colloquially known as pyro (because one vendor for this product is a company called Pyrotenax). A similar product sheathed with metals other than copper is called mineral insulated metal sheathed (MIMS) cable. MI cable fulfills the passive fire protection called circuit integrity, which is intended to provide operability of critical electrical circuits during a fire. It is subject to strict listing and approval use and compliance. MI cable is made by placing copper rods inside a circular copper tube and filling the intervening spaces with dry magnesium oxide powder. The overall assembly is then pressed between rollers to reduce its diameter (and increase its length). Up to seven conductors are often found in an MI cable, with up to 19 available from some manufacturers. Since MI cables use no organic material as insulation (except at the ends), they are more resistant to fires than structures that are wired with plastic-insulated cables.