1.1 This specification covers a thermoplastic insulation of poly(vinyl chloride) or the copolymer of vinyl chloride and vinyl acetate. 1.2 This insulation is recommended for use in power and control circuits at temperatures not higher than 75 °C. At a thickness of 15 mils (0.38 mm), application is limited to voltage ratings below 300 V, and to dry locations. At a thickness of 30 mils, the application range is widened to dry or wet applications, and to a voltage rating of 600 V.