What this MCCB is and what it does
The Siemens SENTRON 3VA1220-5GF42-0AE0 is a 4-pole molded case circuit breaker (MCCB) rated for a continuous current of 200 A at 40 °C, with a TM240 thermal-magnetic release for line protection. It carries a breaking capacity of 187 kA at 240 V, 121 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V — so at 415 V it can safely interrupt a fault current over 120 kA without upstream damage. The rated insulation voltage is 800 V, and the front face is IP40 rated for panel environments.
Thermal derating and real-world current handling
The 200 A rating holds from 40 °C through 50 °C. At 55 °C it derates to 194 A, at 60 °C to 188 A, at 65 °C to 182 A, and at 70 °C to 176 A. If the panel ambient runs hot — say 60 °C inside the enclosure — the breaker still carries 188 A continuous without nuisance tripping.
Physical fit and auxiliary contacts
Dimensions are 158 mm high, 140 mm wide, and 70 mm deep. It ships with four HQ auxiliary switches built in — no separate add-on module needed for status feedback. The N-conductor protection is set to 100% of phase rating, which matters for panels feeding nonlinear loads where the neutral carries full phase current.