Cricuit-breakers must make and break all currents withing the scope of their ratings, from small inductive and capacitive load currents up to the short-circuit current, and this under all fault conditions in the power supply system such as earth faults, phase opposition and so on.
Further information you find in the booklet Vacuum Switching Technology and Components for Medium Voltage - Your guide on the right hand side.


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.
| Rated voltage (kV) | Short-circuit breaking current (kA) | Rated normal current (A) | |||||
| 1250 | 2000 | 2500 | |||||
| Single-pole | Two-pole | Single-pole | Two-pole | Single-pole | Two-pole | ||
| 17,5 | 25 | ■ | |||||
| 31,5 | ■ | ||||||
| 40 | ■ | ||||||
| 50 | ■ | ||||||
| 27,5 | 25 | □ | □ | □ | □ | □ | |
| 31,5 | □ | □ | □ | □ | □ | □ | |
■ Circuit-breaker for 16⅔ Hz
□ Circuit-breaker for 50/60 Hz
Sample 1: Type 3AH4755-4; 16⅔ Hz

| Rated voltage | Normal current | Short-ciurcuit breaking current |
| 17,5 kV | 2000 A | 31,5 kA |
Sample 2: Typ 3AH4794-2; 50/60 Hz

| Rated voltage | Normal current | Short-ciurcuit breaking current |
| 27,5 kV | 2500 A | 25 kA |
Sample 3: Typ 3AH4785-6...-ZD31; 50/60 Hz

| Rated voltage | Normal current | Short-ciurcuit breaking current |
| 27,5 kV | 2500 A | 31,5 kA |
Please find additional dimension drawings and data in our catalogue.
3AH47 Vacuum Circuit-Breakers for Traction applications