What this MCCB is and what it does
The Siemens 3VA1216-5MH32-0KH0 is a SENTRON molded case circuit breaker (MCCB) designed specifically for starter protection — meaning it's built to protect motor starters and their associated control circuits, not just general distribution. Three poles, rated 160 A at 40 °C ambient, with a rated insulation voltage of 800 V. The breaking capacity drops as system voltage climbs: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 4.5 kA at 690 V. That's a high-interrupting rating at the lower voltages, suited for high-fault-current industrial panels where you need selectivity without cascading upstream.
Thermal derating — the real-world current you can carry
The 160 A rating holds flat from 40 °C through 50 °C. Above that, it steps down: 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 hot — say, a packed enclosure near a furnace line — you need to size the breaker for the derated figure, not the nameplate. The maximum power loss is 33 W, which matters for heat buildup inside a sealed cabinet.
Integrated auxiliary and shunt trip — what's inside the case
This variant ships with two auxiliary switches plus one trip alarm switch (the HQ configuration), and a shunt trip (STL) release built in. That means you get remote status feedback and remote tripping capability without adding external modules. No undervoltage release, no ground-fault monitoring, no communication module — it's a straightforward protective device for motor starter duty. The shunt trip lets a PLC or safety relay kill power on demand, which is standard for emergency-stop chains on conveyor or pump starters.
Physical fit and panel integration
Dimensions are 105 mm wide, 158 mm high, 70 mm deep. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C.