What this 3VA1 MCCB is and what the ratings mean for fit
The Siemens 3VA1140-4GE42-0AA0-ZD00 is a 4-pole IEC frame 160 molded-case circuit breaker in the 3VA1 series, sized for line protection in a 40 A branch. The 36 kA Icu at 415 V is the breaking capacity class S rating — it can safely interrupt a fault current up to that level without upstream fuses needing to clear first, which matters for panel selectivity studies where the main breaker must hold through a downstream fault. The TM220 thermal-magnetic trip unit gives an adjustable overload protection band from 28 A to 40 A (Ir) and a fixed short-circuit pickup at 10 × In (Ii = 400 A). The 100% N-conductor protection means the neutral pole is fully rated and trips with the phase poles — required on 4-wire systems where the neutral carries unbalanced load current and cannot be left unprotected. This variant includes a nut keeper kit and is specified for a DC Power OEM in China, so the accessory kit and the OEM-specific configuration are already baked into the order code — no separate accessory ordering needed for that application.