What this MCCB is and what the ratings mean for fit
The Siemens 3VA1220-6MH32-0KA0 is a SENTRON molded case circuit breaker (MCCB) rated 200 A continuous on a 3-pole frame, designed specifically for starter protection — meaning it's built to coordinate with motor contactors and overload relays in motor control centers, not just as a feeder breaker. The 200 A rating holds flat from 40 °C up to 50 °C; above that it derates to 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C, so if your panel ambient runs hot, size the load accordingly. The interrupting ratings tell you where this breaker can be installed on the fault-current curve: 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 4.5 kA at 690 V. That 220 kA at 240 V is a high-interrupting-capacity (HIC) frame — it handles the full available fault current at a typical 240 V industrial service entrance without needing a current-limiting fuse upstream. At 690 V the 4.5 kA rating is lower, so verify the available fault current at that voltage before committing the BOM line. The overcurrent release is a TM120M — a thermal-magnetic unit with a 120 A fixed magnetic pickup, so it's set for motor-starting inrush rather than feeder protection. The auxiliary release is a shunt trip (STL), meaning you can remotely trip the breaker via a control voltage, which is standard for emergency-stop circuits or remote shutdown. Insulation voltage is rated 800 V, giving headroom for 690 V systems. Max power loss is 42 W, worth factoring into enclosure heat calculations.
Panel fit and integration
Dimensions: 105 mm wide, 158 mm tall, 70 mm deep. That 105 mm width is a 3-pole frame size — it fits standard Siemens 3VA mounting feet and busbar connectors. The 70 mm depth is shallow enough for most 200 mm deep enclosures; check gland-plate clearance if you're back-paneling with cable ducts. The design is a molded case with a rotary handle, so it mounts directly to a back panel or DIN rail via the 3VA adapter kit.