What this MCCB is and what it does
The Siemens SENTRON 3VA1220-4GF42-0BH0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 200 A at 40 °C through 50 °C, with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity is 121 kA at 240 V, 75.6 kA at 415 V, 25 kA at 440 V, and 11.9 kA at 690 V — figures that define the maximum fault current it can safely clear at each voltage level without upstream coordination failure. The breaker is fitted with an undervoltage release (UVR) and comes with 2 auxiliary switches plus 1 trip alarm switch (HQ configuration), giving the panel builder both status feedback and a shunt-trip path for remote or safety-circuit dropout. It is a 100%-rated N-conductor protection design, meaning the neutral pole is fully rated to carry the same current as the phase poles — no derating needed for 4-wire systems with high neutral harmonics.
Thermal derating and real-world current capacity
The 200 A rating holds flat from 40 °C to 50 °C ambient. Above that, it derates: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. If your panel ambient runs hot, size the load to the derated figure, not the nameplate 200 A.
Physical fit and panel integration
Dimensions are 158 mm high, 140 mm wide, and 70 mm deep. The 70 mm depth is shallow enough for most standard distribution panels without interfering with the rear wiring trough or busbar shroud. The IP40 front-face protection means it is rated against solid objects over 1 mm but not against water ingress — keep it inside a dry enclosure. The auxiliary trip accessory specified for this unit is order code 3VA9608-0BB11; if your BOM already includes that accessory, the fit is direct.