What this breaker is and what it does
The Siemens 3VA1140-4ED42-0AA0-ZD00 is a 4-pole IEC frame 160 molded case circuit breaker from the 3VA1 series, configured as a line protection TM210 thermal-magnetic unit with a fixed overload setting of 40 A and a fixed short-circuit pickup at 10 times In. Its breaking capacity class S delivers 36 kA at 415 V, which means it can safely interrupt fault currents up to that level without upstream coordination failure — a spec that governs panel SCCR headroom in industrial distribution. This variant carries a nut keeper kit and is designated for DC Power OEM applications in China. The N conductor is unprotected, so the neutral bar in the panel must be sized for the full fault current — a detail the panel OEM wireman needs on the BOM line.
What the ratings mean for fit
The fixed Ir=40 A overload protection means the breaker is not field-adjustable for motor FLA mismatch — it is sized for a fixed 40 A resistive or lightly inductive load, typical of a panel feeder or a DC power supply input. The Ii=10 x In (400 A magnetic trip) gives a high short-circuit pickup, so nuisance tripping on inrush is unlikely, but it also means the breaker does not provide motor overload protection without an external overload relay. FTFM (Fixed Thermal, Fixed Magnetic) construction locks the protection curve; no trip-unit replacement or dial-down is possible in the field. The 4-pole configuration with unprotected N is common in 3-phase + neutral distribution where the neutral is not switched — verify the panel design accommodates this before committing the BOM line.