Nowadays circuit-breakers are used for the most varied of tasks-they switch all kinds of devices, including transformers, overhead lines, cables, capacitors, reactors, motors, filter circuits and arc furnaces. They must be suitable for both prolonged idle times and an extremely high number of operating cycles. Low short-circuit ratings required by supply systems are up against the demand for high breaking currents in industrial applications.

The 3AH circuit-breakers for medium voltage
The Siemens 3AH vacuum circuit-breakers cater for all medium-voltage requirements. They are maintenance-free up to 10.000 operating cycles, have a long service life and function with enhanced reliability.