What this MCCB is and where it fits
The Siemens 3VA1220-6MH32-0AG0 is a SENTRON molded case circuit breaker (MCCB) in the starter protection variant — 3-pole, 200 A rated continuous current (Iu), with a TM120M thermal-magnetic trip unit. That TM120M designation means the thermal element is fixed at 200 A and the magnetic pickup is set for motor-starting inrush, not general distribution. It's built for motor branch circuits where you need coordinated protection against overload and short-circuit without nuisance tripping on startup. Rated insulation voltage is 800 V (Ui), and the interrupting ratings climb to 220 kA at 240 V AC, 154 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V — so it handles high available fault current on the line side of a motor starter without needing a current-limiting fuse upstream. The auxiliary contact configuration is one auxiliary switch plus one trip alarm switch (HP type), which gives you a separate signal for the breaker having tripped vs. being manually opened — useful for remote fault annunciation in a PLC input.
Thermal derating and ambient limits
The 200 A rating holds flat from 40 °C through 50 °C ambient. Above that it derates: 192 A at 55 °C, 188 A at 60 °C, 184 A at 65 °C, and 180 A at 70 °C. If your panel ambient runs hot — say near a furnace line or in a sealed enclosure — factor that 180 A floor at 70 °C into your load calculation. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The IP40 front protection is typical for panel-mounted MCCBs — it keeps tools and fingers out but isn't rated for washdown environments.