What this MCCB is and where it fits
The Siemens SENTRON 3VM1220-5GE42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection. It carries a continuous current of 200 A up to 50 °C, derating to 176 A at 70 °C, so in a warm panel you lose about 12 % of the headroom — plan your load margin accordingly. The TM220 thermal-magnetic release handles overload and short-circuit tripping without an external trip unit. It is designed for 690 V AC (max. rated operational voltage) and 500 V DC, with an insulation voltage of 800 V.
Breaking capacity — the number that decides your fault level
This MCCB interrupts 187 kA at 240 V AC, 121 kA at 415 V, 76 kA at 440 V, and 30 kA at 500 V. Those are the rated short-circuit breaking capacities (Icu) at each voltage. If your transformer secondary or generator bus can deliver a prospective fault current higher than the rating at your system voltage, this breaker is not the right choice — you need a higher-rated frame or a current-limiting upstream device. The 187 kA at 240 V is useful for high-fault 240 V distribution panels; at 415 V the 121 kA covers most industrial switchboards.
Mounting and integration
The breaker measures 70 mm deep, 140 mm wide, and 158 mm high — a 4-pole MCCB that fits a standard panel footprint. Front IP40 protection means it is suitable for clean indoor enclosures but not for washdown or outdoor exposure. The design of the N-conductor protection is 100 %, so the neutral pole is fully rated and trips with the phase poles — no need for a separate neutral disconnect. No undervoltage release, no voltage trigger, no communication function: it is a standalone thermal-magnetic breaker with no auxiliaries built in.