What it is and what the ratings mean
The Siemens 3VA1110-4GD42-0AA0-ZD00 is a 4-pole IEC frame 160 molded-case circuit breaker from the 3VA1 series, configured for line protection with a TM210 thermal-magnetic trip unit. The breaking capacity class S delivers an Icu of 36 kA at 415 V — that is the maximum fault current it can safely interrupt without damage, which sets the short-circuit withstand for the downstream panel. For a 415 V distribution board, 36 kA covers most industrial service-entrance and sub-distribution scenarios where the available fault current stays under that threshold. The overload protection is fixed at Ir = 100 A (the thermal element), and the short-circuit pickup is fixed at Ii = 10 × In, meaning the magnetic trip fires at 1000 A. The N conductor is protected at 100% of the phase rating, so this breaker suits 4-wire systems where the neutral carries full phase current — common in three-phase four-wire distribution with non-linear loads. The nut keeper kit is included for DC Power OEM builds in China, which means the breaker ships with the hardware needed for secure bus-bar mounting in that specific OEM context.