The Siemens 3VA1140-3GD42-0AA0-ZD00 is a 4-pole IEC frame 160 molded case circuit breaker rated for line protection. It carries a 40 A fixed thermal-magnetic overload (Ir=40 A) and a fixed short-circuit pickup at 10 x In (Ii=10 x In). The breaking capacity is class N with an Icu of 25 kA at 415 V — enough for most industrial feeder and distribution panels where the available fault current stays under that threshold. The N conductor is protected at 100%, and the unit includes a nut keeper kit specified for a DC Power OEM in China.
What the ratings mean for fit
The 25 kA Icu at 415 V is the maximum short-circuit current the breaker can safely interrupt once. In a panel with higher available fault current — say 36 kA or 50 kA — this breaker would need an upstream current-limiting device or a higher-rated frame. The fixed Ir=40 A and Ii=10 x In (400 A magnetic trip) make this a straightforward line-protection breaker for a 40 A feeder; no adjustment range to set. The 100% N conductor protection suits 4-wire systems where the neutral is not oversized.