ABSTRACT
Mineral insulated (MI) cables have been in use for a sufficient number of years to have stood the test of time. These cables have an insulation of highly compressed magnesium oxide powder (MgO) between cores and sheath. During manufacture the sheath is drawn down to the required diameter; consequently the larger sizes of cable yield shorter lengths than the smaller sizes. Generally MI cable needs no additional protection as copper is corrosion resistant. However, in certain hostile environments, or if a covering is required for aesthetic or identification purposes, MI cable is available with PVC or LSF covering.
