What this MCCB is and what it carries
The Siemens 3VA1216-4EF42-0AA0 is a SENTRON molded case circuit breaker (MCCB) configured for line protection — meaning it sits at the feeder, not at a load branch, and its job is to protect the cable and buswork against overload and short-circuit. It is a 4-pole unit rated 160 A continuous at 40 °C, with a TM240 thermal-magnetic release that combines a bimetal element for overload curves and a fixed magnetic trip for short-circuits. The interrupting capacity hits 121 kA at 240 V, 75.6 kA at 415 V, and 52.5 kA at 440 V — numbers that tell you it is sized for high-fault industrial distribution, not light commercial.
Ratings that govern the fit
The 160 A continuous rating holds flat from 40 °C up to 50 °C, then derates stepwise: 156 A at 55 °C, 151 A at 60 °C, 147 A at 65 °C, and 142 A at 70 °C. If your panel ambient runs above 50 °C, the effective ampacity is lower than the nameplate — plan the load accordingly. The interrupting ratings across voltage levels are what decide whether this breaker clears a fault without rupturing: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V. Match the available fault current at your system voltage; if your site has a 65 kA fault at 415 V, this breaker has headroom. The insulation voltage is rated 800 V, so it is comfortable on 690 V systems within the interrupting envelope.
Panel fit and physical constraints
The 3VA1216-4EF42-0AA0 measures 158 mm high, 140 mm wide, and 70 mm deep — a 4-pole MCCB that fits standard distribution panel footprints. The front face carries an IP40 protection rating, meaning it is protected against tools and wires larger than 1 mm but not sealed against water ingress; keep it inside an enclosure rated for the environment. Maximum power loss is 33 W, which matters for thermal budgeting inside a sealed cabinet — that heat has to be moved. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.