The Siemens SENTRON 3VA1220-5EF42-0JA0 is a 4-pole molded case circuit breaker (MCCB) rated for line protection. It carries a TM240 thermal-magnetic overcurrent release and a shunt trip (STL) auxiliary release. Rated 200 A continuous at 40 °C, it holds that current up to 50 °C before derating to 176 A at 70 °C — so in a hot panel near a kiln or furnace, you still get 176 A without tripping on ambient alone. Interrupting capacity runs from 187 kA at 240 V down to 17 kA at 690 V. That 187 kA figure at 240 V covers high-fault utility feeds; the 17 kA at 690 V still clears most industrial fault levels on 690 V distribution. Insulation voltage is rated 800 V, so the breaker is suitable for 690 V line-to-line systems with margin.
Sizing and ambient derating
The TM240 release is a fixed thermal-magnetic unit — no interchangeable trip block. Full 200 A rating holds through 50 °C; above that, derate linearly to 176 A at 70 °C. If your panel ambient runs 55 °C, the breaker is good for 194 A continuous. That derate curve is the number that governs real-world sizing, not the 200 A nameplate.
Mounting and panel fit
The breaker measures 70 mm deep, 140 mm wide, and 158 mm high. It mounts on a DIN rail or directly to a backplate via the molded case lugs. The 140 mm width is standard for a 4-pole MCCB in this frame size — no surprises for panel layout. The 70 mm depth leaves clearance for rear-connected busbars or a shallow enclosure.