This standard covers requirements for the external insulation of outdoor ac high-voltage circuit breakers rated on a symmetrical current basis.

This standard covers requirements for the external insulation of outdoor ac high-voltage circuit breakers rated on a symmetrical current basis.

The purpose of this standard is to establish the basis of rating structure and terminal connection mechanical loading requirements for external insulation for outdoor ac high voltage circuit breakers rated on a symmetrical basis. It is intended as an addition to American National Standards for ac high-voltage circuit breakers rated on a symmetrical current basis: C37.03-1964, 37.04-1964, C37.05-1964, C37.06-1971 , C37.07-1969, C37.09-1964, C37.010-1972, C37.12-1969 and their supplements. It is planned eventually to incorporate its contents into these basic standards at some future time.