Ratings and fit — what the numbers mean for a panel
The Siemens 3VA1150-3GD42-0AA0 is a SENTRON molded case circuit breaker (MCCB) with a fixed 50 A rating across all four poles — it does not have adjustable thermal or magnetic settings, so the trip curve is locked at the factory. That fixed 50 A holds from 40 °C through 50 °C ambient; above that it derates linearly to 45 A at 70 °C, which matters if this breaker lands in a crowded, hot enclosure without forced cooling. Short-circuit interrupting capacity (SCCR) varies sharply with line voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at 500 V or 690 V. That 11.9 kA floor at 690 V is the number to check if the panel feeds a 690 V drive bus — the breaker will clear a fault up to that level without welding contacts or venting plasma into the enclosure. The TM210 overcurrent release combines a thermal bimetal for overload protection and a magnetic solenoid for short-circuit response. Rated insulation voltage is 800 V, so the breaker is electrically rated for 690 V systems with margin. Maximum power dissipation is 14.6 W — negligible for most panels but worth summing if ten of these sit side-by-side in a sub-distribution board. IP40 on the front means the breaker face is protected against tools and wires >1 mm, but the terminals are not sealed — mount it inside a rated enclosure in washdown or outdoor locations.
Physical fit — what the 70 mm depth means for the enclosure
The breaker measures 70 mm deep, 101.6 mm wide, and 130 mm tall. That 70 mm depth is the critical dimension for shallow backpanels or door-mount applications — it fits a standard 200 mm deep enclosure with room for wiring gutters. Width of 101.6 mm (4 inches) is the standard 4-pole MCCB footprint; it mates with the same busbar and lug kits as other SENTRON 3VA 4-pole breakers.