The Siemens 3VA1220-4GF42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 200 A continuous current across a 40 °C to 50 °C ambient band — no derating needed until you hit 55 °C, where it steps to 194 A. That 200 A frame is the same physical package whether you're protecting a 160 A or 200 A feeder; the TM240 thermal-magnetic release sets the actual trip threshold. Four poles cover three-phase plus neutral, common for main incomers or distribution in North American and IEC panels alike. Breaking capacity is the headline: 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V. The 690 V rating at 11.9 kA also covers 600 V class industrial systems. Dimensions are 140 mm wide, 70 mm deep, 158 mm tall — a 4-pole frame that fits standard MCCB panel cutouts.
At 55 °C it drops to 194 A, at 60 °C to 188 A, at 65 °C to 182 A, and at 70 °C to 176 A. That's a gentle slope — about 3 % per 5 °C above 50 °C — which gives you headroom in a warm enclosure.
The 140 mm width is the critical dimension for multi-pole lineup spacing — typical 4-pole MCCB cutout is 140 mm wide.