Siemens VL circuit breakers are designed on the principal of contact magnetic repulsion. This allows the current limiting effect of the breakers to help protect the system components from the thermal and dynamic magnetic effects of short circuit currents in the event of an electrical fault. VL Circuit Breakers feature N-Class (35kA), H-Class (65kA) and L-Class (100kA) interrupting ratings. They also feature both thermal magnetic and electronic trip units across the entire product line, assuring compatibility for virtually any application. All of the VL Trip Units are UL listed for field installation and measure true RMS current. This type of measurement ensures the most accurate means of measuring currents in todays harmonic filled electrical distribution systems.