The Siemens SENTRON 3VM1040-3ED46-0AA2 is a 4-pole molded case circuit breaker rated 40 A continuous at 40 °C, with a TM210 thermal-magnetic overcurrent release (LI protective function). It's in the N switching capacity class, meaning it's sized for standard industrial distribution — not the high-breaking version, but still capable of 76 kA at 240 VAC and 53 kA at 415 VAC. Frame size is 100 A, so the breaker itself is physically larger than the 40 A trip unit suggests — the same frame can be re-rated up to 100 A if you swap the release later.
The interrupting ratings drop fast as voltage climbs: 76 kA at 240 V, 53 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 500 V. If your system runs 480 V wye, the 440 V figure is the closest published value — 32 kA — and that's the one to check against your available fault current. The thermal curve holds 40 A from 40 °C up to 50 °C, then derates to 39 A at 55–60 °C and 38 A at 65 °C, 37 A at 70 °C. That's a shallow derate; you don't lose much headroom in a warm enclosure. Box terminals on the front for main circuit connection — standard panel wiring, no special lug kit needed.
Front-connected box terminals accept copper or aluminum conductors — strip length and torque per the terminal marking on the breaker. Maximum power loss is 14 W at rated current — negligible for panel heat calc, but worth noting if you're packing a dozen of these in a small enclosure.