What this MCCB is and where it lands
The Siemens 3VA1220-5MH32-0HA0 is a SENTRON molded case circuit breaker (MCCB) designed for starter protection — meaning it's built to sit ahead of a motor starter or contactor, providing both branch-circuit fault protection and the overcurrent coordination a motor branch needs. It's a 3-pole, 200 A frame with a TM120M thermal-magnetic release, so the thermal element handles overloads and the magnetic element handles short circuits, no electronic adjustment. The built-in shunt trip (STL) lets a remote signal or safety circuit force the breaker open without anyone walking to the panel.
Breaking capacity — what the voltage columns tell you
This MCCB carries a 187 kA interrupting rating at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 4.5 kA at 690 V. That's a steep derate curve — the breaker is happiest on 240 V or 415 V systems where fault currents can be high, but at 690 V it's only rated for 4.5 kA, which is fine for most 690 V distribution but not for high-fault locations. The rated insulation voltage is 800 V, so the internal clearance and creepage are sized for 690 V line-to-line use.
Thermal derating — the real-world current
The 200 A rating holds flat from 40 °C to 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 a sealed enclosure near a furnace line — you lose 24 A off the nameplate. The maximum power loss is 42 W, which is modest for a 200 A frame, so the self-heating contribution to the enclosure rise is manageable. Operating range is -25 °C to 70 °C; storage range -40 °C to 80 °C.
Panel fit — dimensions and integration
The breaker measures 105 mm wide, 158 mm high, and 70 mm deep. That 105 mm width is a standard 3-pole MCCB footprint for DIN-rail or panel-mount backplates — it occupies roughly four 18 mm module spaces on a DIN rail, though the SENTRON 3VA series typically uses screw-mount lugs or a mounting plate rather than a snap-on DIN foot for this frame size. The 70 mm depth means it clears a 100 mm deep enclosure with room for wiring behind the breaker.