The BALTO System was developed to generate, and inject into the circuit, very high and precise DC test currents in order to carry out functional tests on high-speed DC circuit breakers. The problems arising during testing of high-speed DC circuit breakers frequently worry the service and maintenance personnel of rail-way organisations, especially when it comes down to checking and adjusting the thresholds. To meet the requirements encountered in the market, the innovative BALTO system was subject to the specifications worked out on the basis of requests from high-speed DC circuit breakers’ manufacturers and various railways/train operators and public transport companies.