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. The unit includes an undervoltage release (UVR) as the auxiliary release, plus two auxiliary switches and one trip alarm switch (HQ) — a configuration that allows remote status monitoring and undervoltage protection without an external relay. Rated insulation voltage is 800 V, and the maximum power loss is 17.1 W.
Breaking Capacity and Thermal Derating
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.
Mounting and Integration
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).