Siemens SENTRON 3VA1150-6EF32-0DH0 — 50 A MCCB with Undervoltage Release
The Siemens SENTRON 3VA1150-6EF32-0DH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current of 50 A at 40 °C and derating to 45 A at 70 °C. Its interrupting capacity reaches 220 kA at 240 V AC and 154 kA at 415 V AC — figures that place it in the high-breaking-capacity class for industrial distribution panels where fault currents can exceed 100 kA.
At 440 V the breaker interrupts 121 kA; at 500 V and 690 V the rating drops to 17 kA — a steep fall that reflects the arc-extinction limits at higher voltages. For a 480 V panel (common in North America), the 121 kA at 440 V is the closest published figure; the 17 kA at 500 V governs above that threshold. Thermal derating is flat from 40 °C to 50 °C (50 A), then drops by 1 A per 5 °C step to 45 A at 70 °C. That means a panel ambient of 55 °C still allows 49 A continuous — within tolerance for most 50 A feeders.
The breaker measures 130 mm high, 76.2 mm wide, and 70 mm deep — a footprint that fits standard Siemens SENTRON 3VA panel-mounting cutouts. The 3-pole design with screw terminals accepts copper or aluminum conductors sized per the manufacturer's terminal range (not listed here, but typical for a 50 A frame).