What this MCCB carries — and what it means on a panel
The Siemens 3VA1220-4EF42-0KA0 is a 4-pole SENTRON molded case circuit breaker rated 200 A at 40 °C, with a TM240 thermal-magnetic release and an integrated shunt trip (STL) for remote tripping. The 121 kA breaking capacity at 240 V tells you it can clear a fault up to that level without upstream fuses or a bigger main — useful for high-fault service entrances or distribution panels where SCCR headroom matters. At 415 V it still breaks 75.6 kA, and at 690 V it holds 11.9 kA, so it's not a one-voltage pony; the ratings follow the voltage curve you'd expect from a frame this size.
Thermal derating — the real current you can run
The 200 A rating holds steady through 50 °C ambient. Above that it starts to step down: 194 A at 55 °C, 188 A at 60 °C, 182 A at 65 °C, and 176 A at 70 °C. If the panel runs hot — say a packed enclosure near a furnace line — the 176 A floor at 70 °C is the number to design to, not the 200 A nameplate. The TM240 release is set for a 240 A frame, so the breaker itself has headroom; the thermal curve is what governs continuous load.
Dimensions and panel fit
The case measures 158 mm high, 140 mm wide, and 70 mm deep. That 70 mm depth is shallow enough to clear a standard 200 mm deep enclosure backpan without the breaker protruding past the gland plate. The 140 mm width for a 4-pole means each pole takes about 35 mm — typical for this frame class. Mounting holes and bus-bar slot pattern match other SENTRON 3VA breakers, so swapping a 3-pole for this 4-pole in the same lineup usually just means shifting the bus work one phase over.
What the approvals and ratings tell a specifier
Rated insulation voltage is 800 V, so it's comfortable on 480 V and 600 V class systems with margin. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The breaker is designed for line protection (not motor protection — that's what the TM thermal curve plus magnetic trip is set up for). No undervoltage release, no ground-fault monitoring, no communication function on this variant. The supplied basic switch code is 3VA12204EF420AA0 if you need to cross-reference internal parts.