What it is and what it does
The Siemens SENTRON 3VA1096-4ED32-0HH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection. It's built around a TM210 thermal-magnetic overcurrent release and carries a shunt trip (STL) for remote opening. The breaking capacity hits 121 kA at 240 V — that's the number that decides whether it clears a high-fault bolted short without welding its contacts shut or cascading upstream. At 415 V it still breaks 75.6 kA, and at 690 V it's 11.9 kA, so it stays selective on most industrial distribution panels. Rated continuous current Iu is 16 A, and it holds that rating from 40 °C up to 50 °C without derating. At 55 °C it drops to 15.36 A, at 70 °C to 14.4 A — useful to know if the breaker sits near a transformer or drive in a warm enclosure.
Fit and panel integration
Width is 76.2 mm, depth 70 mm, height 130 mm — standard SENTRON 3VA frame size. It mounts on a DIN rail or directly to a backplate. The front face carries IP40 protection, so it's fine inside a panel but not for washdown areas. Auxiliary contact version is 2 auxiliary switches plus 1 trip alarm switch (HQ designation). That gives you two NO/NC signal contacts for status feedback plus a dedicated alarm contact that trips on a fault — useful for PLC inputs or annunciator panels without extra wiring.