What it is and what it does
The Siemens SENTRON 3VA1216-6MH32-0AC0 is a 3-pole molded case circuit breaker (MCCB) rated for 160 A at 40 °C, with a TM120M thermal-magnetic overcurrent release. It delivers a 220 kA breaking capacity at 240 V AC, stepping down through 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 4.5 kA at 690 V — that curve tells you this breaker is built for high-fault industrial distribution where the upstream transformer can dump serious energy into a bolted fault. Rated insulation voltage is 800 V, so it's comfortable on 690 V systems with margin. The TM120M release means the thermal element handles overloads and the magnetic element handles short-circuits; no electronic trip unit, no communication module, no ground-fault monitoring — this is a straightforward, field-reliable breaker for main or feeder duty in a panel.
Thermal derating and panel integration
Rated 160 A continuously at 40 °C ambient. Derate linearly through the range: 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 — that 70 °C figure is the one to design to. The 33 W maximum power loss at rated load matters for enclosure heat rise calculations; factor it into your ventilation or forced-air budget. Dimensions are 105 mm wide, 158 mm high, 70 mm deep — a standard 3-pole MCCB footprint that bolts into a SENTRON panelboard or mounts on a mounting plate. The supplied basic switch is order code 3VA12166MH320AA0, and the auxiliary switch block carries two HQ auxiliary switches for status feedback to a PLC or indication lamp.