What the ratings mean for fit
The Siemens SENTRON 3VA1150-5EF36-0BH0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current of 50 A at 40 °C ambient with no derating needed up through 50 °C — at 55 °C it still holds 49 A, and at 70 °C it's at 45 A, so it handles warm panel interiors without a frame size bump. The interrupting ratings tell the real story: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V. That 187 kA at 240 V means it can safely clear a bolted fault on a high-capacity 240 VAC distribution bus without upstream coordination headaches — useful for industrial switchboards or transformer secondaries where available fault current runs high. Rated insulation voltage is 800 V, so it's electrically rated for 690 VAC systems with margin. The design includes an undervoltage release (UVR) and comes with 2 auxiliary switches plus a trip alarm switch (HQ configuration), which means it can signal its state back to a PLC or annunciator panel without a separate interface relay.
Panel integration and mounting
At 130 mm tall, 76.2 mm wide, and 70 mm deep, this MCCB fits a standard three-pole footprint in a distribution panelboard or motor control center bucket. The 76.2 mm width (3 inches) matches the typical SENTRON 3VA frame spacing, so it drops into existing DIN-rail or screw-mounted backpanels without re-drilling. Plan for 70 mm of clearance behind the panel door for the body depth plus wiring space.