What this MCCB is and what it does
The Siemens SENTRON 3VA2110-7MS32-0AB0 is a 3-pole molded case circuit breaker (MCCB) rated for starter protection duty — meaning it's built to sit ahead of a motor starter combination, providing both short-circuit and overload protection for the motor branch circuit. It carries a rated continuous current Iu of 100 A, and that rating holds flat from 40 °C up through 50 °C ambient, so it doesn't derate in a warm panel until you cross 55 °C. The breaking capacity is substantial: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 52.5 kA at 690 V. That kind of high-interrupting rating is what you need when the available fault current at the service entrance is high — typical for large industrial switchboards or transformer secondaries.
Overcurrent release and auxiliary contacts
The overcurrent release is an ETU310M — an electronic trip unit that gives you adjustable thermal and magnetic protection curves, plus ground-fault alarm or trip capability if you add the right module (this unit ships without ground-fault monitoring). The auxiliary contact version is listed as 2 auxiliary switches HP, meaning two high-performance auxiliary contacts that can be wired for status feedback to a PLC or to drive a remote indication lamp. There's no undervoltage release, no voltage trigger, and no communication function on this variant — it's a straightforward power breaker with electronic trip.
Physical fit and panel integration
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep. That depth is the body only — you need to account for the handle throw and any rear-mounted accessories when planning the enclosure depth. The front face carries an IP40 rating, so it's protected against tools and small wires entering the front, but not against water ingress; it's intended for indoor panel mounting, not washdown areas. The operating temperature range is -25 °C to +70 °C, with storage from -40 °C to +80 °C. Maximum power loss at rated current is 75 W — that's heat that has to be dissipated inside the enclosure, so factor it into your thermal budget.