The Siemens SENTRON 3VA1050-4ED42-0JC0 is a 4-pole molded case circuit breaker (MCCB) designed for line protection. It carries a rated current of 50 A across ambient temperatures up to 50 °C, derating to 45 A at 70 °C. Breaking capacity reaches 121 kA at 240 VAC, 75.6 kA at 415 VAC, and holds at 11.9 kA at both 500 V and 690 VAC — that's the SCCR headroom for a 50 A frame in a distribution panel or motor control center. Rated insulation voltage is 800 V.
What the Ratings Mean for Fit
The 50 A rating is continuous at 40–50 °C; above that the thermal derating curve drops it to 45 A at 70 °C. If your panel ambient runs hot, size the load accordingly. The 121 kA at 240 VAC is the interrupting rating — it safely clears a fault up to that level without cascading upstream. The 800 V rated insulation voltage covers 480 V and 600 V class systems with margin. Power loss is 14.6 W maximum, which matters for enclosure heat rise calculations.
Integration Details
The breaker ships with a shunt trip (STL) and two auxiliary switches HQ built in — no separate add-on modules needed for remote tripping or status feedback. Dimensions are 130 mm height, 101.6 mm width, 70 mm depth. It mounts on a DIN rail or panel-mount base in a standard distribution enclosure. No communication function or undervoltage release on this variant.