What this breaker is and what the ratings mean
The Siemens 3VA1120-6GD42-0AA0-ZD00 is a 4-pole IEC frame 160 molded-case circuit breaker with a 70 kA interrupting capacity at 415 V (breaking capacity class H). That 70 kA rating means it can safely clear a fault up to that level without cascading upstream — critical for high-fault panels where the available short-circuit current is substantial. It carries a fixed thermal-magnetic TM210 trip unit: In = 20 A, overload protection Ir fixed at 20 A, and short-circuit protection Ii set at 16 × In (320 A). The N conductor is protected at 100%, and the breaker includes a nut keeper kit — a detail that matters for the DC Power OEM variant built for the China market.