Building insulation materials weak and brittle. Before its risks were recognized, it was used because it was a cheap, effective insulator with a high R-value and its open-cell structure was a good acoustic insulator. Though it absorbed moisture easily, it regained effectiveness as an insulator when dried. Asbestos once found common use as an insulation material in homes and buildings because it is fireproof, a good thermal and electrical insulator, and resistant to chemical attack and wear. It has been found that asbestos can cause cancer when in friable form (that is, when likely to release fibers into the air - when broken,
Insulation system the more difficult to cool rotor winding may be Class F. There are five categories of insulation used by the three different classes of equipment; functional, basic, supplementary, double and reinforced. Insulation system The electrical insulation system for wires used in generators, electric motors, transformers, and other wire-wound electrical components is divided into different classes by temperature and temperature rise. The electrical insulation system is sometimes referred to as "insulation class" or "thermal classification". The different classes are defined by NEMA, Underwriters Laboratories (UL), and IEC standards. The maximum hot-spot operating temperature is reached by adding the rated ambient temperature