The electrical power supply for railway systems requires circuit-breakers with special features. Not only are there single-pole circuit-breakers in normal operation, but also the high requirements regarding operational reliability and number of operating cycles reach far beyond the standards of other applications.
The vacuum circuit-breaker series 3AH47 offers – both for 16⅔ Hz at a rated voltage of 17.5 kV and for 50/60 Hz at a rated voltage of 27.5 kV – an impressive product range with rated normal currents up to 2500 A and rated shortcircuit breaking currents from 25 kA to 31.5 kA, and even up to 50 kA at 17.5 kV.
3AH47 vacuum circuit-breakers control up to 60,000 operating cycles. Minimum maintenance work, such as greasing of operating mechanisms after 10,000 operating cycles and replacement of vacuum interrupters after 30,000 operating cycles, preserves the reliability of these circuit-breakers throughout their entire service life.