This standard applies to machines having rated outputs larger than those included in BS 170 and smaller than those in BS 169 and having windings insulated with Class A material as defined in Appendix A, wound for voltages not exceeding 7,000 Volts. This standard does not apply to turbo-type machines, rotary convertors, motors for traction purposes, or to machines with flame-proof enclosure. This standard may also be applied to machines of larger ratings, by special arrangement between the manufacturer and purchaser. Continuously rated machines to this specification (other than totally-enclosed machines) have a sustained overload capacity as distinct from machines having a continuous maximum rating.

BS 168:1936 - Identical