What this 200 A MCCB does on the line
The Siemens 3VA1220-6MH32-0HA0 is a SENTRON molded case circuit breaker (MCCB) rated for a continuous 200 A at 40 °C, with a TM120M thermal-magnetic overcurrent release. Its 3-pole design and shunt trip (STL) make it a fit for motor branch circuits and feeder protection where you need remote tripping capability — think conveyor drives, pump panels, or compressor starters in a manufacturing line. Breaking capacity is where this breaker earns its keep: 220 kA at 240 V, 154 kA at 415 V, and still 75.6 kA at 440 V. That SCCR headroom means it can sit upstream of smaller branch breakers without worrying about cascading failure during a fault — a real advantage when you're coordinating selectivity in a 480 V panel.
Thermal derating and what it means for your enclosure
The 200 A rating holds flat from 40 °C to 50 °C (–). Above that, it derates: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, 176 A at 70 °C (–). If your panel runs hot — near a drive bank or in a non-climate-controlled room — that derating curve tells you exactly how much margin you lose. Max power loss is 42 W, so plan for that heat inside the enclosure. Rated insulation voltage is 800 V, and the operating range is -25 °C to 70 °C (–). Storage range is -40 °C to 80 °C (–). That storage spec matters for spares sitting on a shelf in an unheated warehouse.
Mounting dimensions and what fits
The 3VA1220-6MH32-0HA0 measures 70 mm deep, 105 mm wide, and 158 mm tall (–). That's a standard SENTRON 3VA1 footprint — it will drop into the same panel cutout and bus bar arrangement as other 3VA1 3-pole breakers. No rewiring needed if you're swapping from a 3VA1112-5EE32-0AA0 or similar; just verify the lug positions match your bus work.