IEC 60044-2:1997

Applies to new inductive voltage transformers for use with
electrical measuring instruments and electrical protective devices
at frequencies from 15 to 100 Hz. This standard relates basically to
transformers with separate windings, but also to autotransformers.
It replaces IEC 60186 (1987) plus Amendments 1 and 2
only for inductive voltage transformers. IEC 60186 remains in force
for capacitive voltage transformers.