scope:

This standard covers nominal voltage ratings for alternating and direct electric current.

The voltage ratings listed herein shall apply to utilization equipment and new systems.

This standard does not apply to new or replacement equipment required to operate on existing systems having voltages other than those covered by this standard and to secondary voltages of control and signal transformers supplying low voltages to such circuits. Effort should be made to utilize standard voltages on replacement items when practicable.

intended Use:

This standard is intended to cover nominal AC and DC voltages produced by generators or power conversion equipment and AC and DC utilization equipment that consume the power.