What this MCCB carries and where it fits
The Siemens 3VA1220-5GF42-0DH0 is a SENTRON molded case circuit breaker (MCCB) rated for 200 A continuous current (Iu) in a 4-pole configuration, built for line protection duty. It carries a TM240 thermal-magnetic overcurrent release, meaning the thermal element tracks the load current and the magnetic element handles short-circuit trips — no electronic adjustment, just a fixed curve that matches standard feeder and distribution applications. Breaking capacity is specified at four voltage levels: 187 kA at 240 V, 121 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V. That 187 kA at 240 V is a high-interrupting rating for a 200 A frame — it clears severe fault currents without cascading upstream, which matters when this breaker sits close to a large transformer or in a high-capacity switchboard. The thermal derating curve is published from 40 °C through 70 °C: it holds 200 A up to 50 °C, then drops to 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 above 50 °C, size the load to the derated figure, not the nameplate 200 A.
Mounting and panel integration
Dimensions are 158 mm high, 140 mm wide, 70 mm deep. The 140 mm width is standard for a 4-pole MCCB in this frame size — it occupies one full unit of panel width on a DIN-rail or bolted busbar system. The 70 mm depth leaves clearance behind the panel door for wiring and auxiliary wiring channels. Front face carries IP40 protection — suitable for dry indoor panels where tools or fingers might contact the front, but not rated for washdown or outdoor exposure. The auxiliary contact block is configured as 2 auxiliary switches plus 1 trip alarm switch (HQ type), which gives separate signaling for breaker position and fault condition without extra wiring.