The BALTO Compact 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 that arise during the testing of high-speed DC circuit breakers frequently worry service and maintenance personnel, especially when it comes down to checking and adjusting the thresholds. The BALTO Compact has been developed specifically for testing DC high-speed circuit breakers at rolling stock, tramways and primary infrastructure. It is also suitable for on-board maintenance in marine applications. Special attention was given to the weight and size of this compact version resulting in an ergonomic design that permits usage in small spaces.