What this MCCB is and what the ratings mean
The Siemens SENTRON 3VA1220-5GF42-0AA0 is a 4-pole molded case circuit breaker rated 200 A continuous, designed for line protection in distribution panels. The TM240 thermal-magnetic trip unit gives fixed thermal and magnetic settings — no field adjustment, which simplifies ordering but locks the curve to the factory calibration. At 240 V the interrupting capacity hits 187 kA; at 415 V it's 121 kA, at 440 V it's 75.6 kA, at 500 V it's 30 kA, and at 690 V it's 17 kA. That means the breaker can handle very high fault currents at lower voltages — typical for a main or feeder breaker in a 480 V or 400 V industrial panel where the available fault current is substantial.
Thermal derating and panel integration
The breaker is rated 200 A continuously up 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 the panel ambient runs hot — say next to a drive cabinet or in a non-conditioned enclosure — the derating curve tells you the real ampacity without guessing. The IP40 front protection means it's splash-safe from the front but not sealed; mount it in a clean, dry enclosure. Dimensions are 70 mm deep, 140 mm wide, 158 mm high, so it fits standard SENTRON 3VA panel footprints.
Power loss and compliance
Maximum power loss is 42 W at rated current — useful for enclosure thermal calculations. The insulation voltage is rated 800 V. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. No undervoltage release, no communication function, no ground-fault monitoring on this variant. Compliance documentation (RoHS, REACH, UL, IEC) is provided with the product; typical for Siemens SENTRON series.