MCCB for line protection with high interrupting capacity
The Siemens SENTRON 3VA1050-4ED42-0HC0 is a 4-pole molded case circuit breaker rated 50 A at 40 °C, designed for line protection in distribution panels. Its interrupting capacity hits 121 kA at 240 V AC, dropping to 75.6 kA at 415 V and 52.5 kA at 440 V — figures that matter when coordinating with upstream gear for selective coordination. At 500 V and 690 V it still holds 11.9 kA, covering industrial services where fault current is lower but voltage is higher. Rated insulation voltage is 800 V, so this breaker comfortably handles 690 V line-to-line systems with margin. Maximum power loss runs 14.6 W — a number to factor into enclosed panel thermal calculations if the breaker is fully loaded in a sealed box. The unit ships with a factory-fitted shunt trip (STL) and two auxiliary switches (HQ), so remote tripping and status feedback are wired in from the start. No undervoltage release, no ground-fault monitoring, and no communication module on this variant — it's a straight line-protection breaker with remote-trip capability.
Thermal derating and operating limits
Current rating holds at 50 A from 40 °C up to 50 °C ambient. Above that it derates: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If the panel ambient runs hot, the continuous load needs to stay under these adjusted numbers. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Panel fit and dimensions
The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep. That 101.6 mm width is a standard 4-inch footprint for a 4-pole MCCB — it fits the same cutout and bus-bar spacing as other SENTRON 3VA frames in this current class. The depth of 70 mm (2.76 in) leaves enough room behind the panel door for wiring and the shunt trip leads.