This standard applies to electrical and electronic test, measuring, controlling and related equipment. This standard applies to equipment that is rated for connection to supply circuits that exceed extra-low voltage and that do not exceed 480 volts rms., between phases for three-phase supply circuits or 250 volts rms., single-phase or dc. Standard does not apply to: (1) medical and laboratory equipment; (2) watt-hour meters and associated equipment installed by electrical utility companies for measuring electrical energy and related quantities; and (3) general use battery charges, auxiliary supply sources, substitute power supplies, or laboratory type power supplies not specifically rated for use with measuring or testing equipment.