scope:

This standard applies to rotating a.c. machines for rated voltages from 3 kV to 15 kV inclusive and incorporating form-wound stator coils. This standard specifies the rated phase-to-earth impulse voltage withstand levels and the test procedures and voltages to the main and interturn insulation of sample coils to prove the impulse voltage withstand level of the machine, and gives some guidance for routine tests. The standard covers surges originating from lightning but consideration is being given to extending the standard to cover surges originating from switching vacuum and other circuit-breakers.