What this 3VA1 frame 160 breaker carries
The Siemens 3VA1140-3GF42-0AA0-ZD00 is a 4-pole IEC circuit breaker on the 3VA1 frame 160, rated In=40A with a TM240 thermal-magnetic trip unit. Breaking capacity class N gives it Icu=25kA at 415 VAC — enough for most distribution panels downstream of a transformer, but check your available fault current before committing the BOM line. Overload protection is adjustable Ir=28A...40A via the TM240 dial, and short-circuit pickup Ii=5...10 x In. The N conductor is protected at 100%.
Integration notes for the panel
Mounts on a standard DIN rail or bolts into a panel via the frame 160 footprint. The nut keeper kit (part of the ZD00 suffix) is meant for DC Power OEM builds in China — keeps the terminal nuts captive during assembly, which saves time on a production line. Four-pole configuration covers three-phase plus neutral. If your distribution uses a solidly-grounded wye system with a full-size neutral, this breaker handles it without a separate neutral disconnect.
What the ratings mean for your coordination study
Icu=25kA at 415 V is the ultimate short-circuit breaking capacity — the breaker can clear one fault at that level and still be usable afterward (though you'd replace it in practice). For selectivity downstream of a 630 kVA transformer with around 20 kA available, this holds. Upstream of a larger transformer or in a high-fault location, you'd need class S or H (higher Icu). The TM240 thermal unit gives a flat time-current curve typical of thermal-magnetic breakers — no electronic adjustment for I²t or ground fault. That's fine for cable protection and general distribution; for motor circuits you'd want an electronic trip with adjustable curves.