What this MCCB is and what it protects
The Siemens SENTRON 3VA1216-5MH32-0JA0 is a 3-pole molded case circuit breaker rated for 160 A continuous current (Iu), built in the starter protection variant — meaning it is designed to protect motor starters and similar inductive loads against short-circuit and overload, not just general distribution feeders. The overcurrent release is a TM120M thermal-magnetic unit, so the thermal element handles overloads and the magnetic element clears short-circuits — no electronic adjustment, but inherently reliable for fixed-threshold motor protection. An integrated shunt trip (STL) release (order code 3VA9688-0BL32) allows remote tripping via a control signal, which is standard for emergency-stop circuits or supervisory shutdown in automated lines.
Breaking capacity and selectivity planning
This MCCB delivers 187 kA at 240 V, 121 kA at 415 V, 30 kA at 440 V, and 17 kA at 690 V — those are the interrupting ratings at each voltage level, so a site electrical engineer can coordinate selectivity with upstream breakers and confirm the SCCR meets the available fault current at the panel. Rated insulation voltage (Ui) is 800 V.
Thermal derating and panel integration
The breaker holds 160 A up to 50 °C ambient; at 55 °C it derates to 153.6 A, at 60 °C to 150.4 A, at 65 °C to 147.2 A, and at 70 °C to 144 A — so if the enclosure runs hot, the continuous current must be reduced accordingly. Dimensions are 105 mm wide, 158 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without surprises. Front protection is IP40, so it is splash-proof from the front but not sealed against dust ingress — fine for a clean panel environment, not for washdown zones.