This European Standard specifies the characteristics of three-pole circuit breakers, temperature compensated with a rated current from 1 A to 25 A, used in aircraft on-board circuits at a temperature between - 55 °C and 125 °C for ratings ≤ 15 A and - 55 °C to 90 °C for ratings > 15 A and at an altitude of 22 000 m max. These circuit breakers are operated by a push-pull type single pushbutton (actuator), with delayed action 'trip-free' tripping. They will continue to function up to the short-circuit current.