This standard specifies the characteristics of three-pole circuit breakers, temperature compensated with a rated current from 20 A to 50 A, used in aircraft on-board circuits at a temperature between - 55 °C and 90 °C and at an altitude of 15 000 m max. These circuit breakers are operated by a push-pull type single push button (actuator), with delayed action "trip-free" tripping with a polarized signal contact which is open when main contacts are closed, and inversely. They are connected on supp