This standard applies to all air circuit breakers with interrupting rating over 10@000 amperes as follows: A. Air circuit breakers 1500 volts or less alternating current and 3000 volts or less direct current. Special purpose air circuit breakers for the control of generators@ rectifiers and for heavy duty applications@ in addition to meeting these standards generally have other requirements not yet standardized. B. All field discharge breakers comprising air circuit breaker contact elements with field discharge contacts added@ of any ampere rating single pole or multipole. C. Air circuit breakers assembled as integral units in supporting and enclosing housings of insulation material for voltage ratings up to and including 600 volts alternating current@ 250 volts direct current. D. Air circuit breakers@ when in individual enclosures usually built of steel for separate mounting.