What this MCCB is and what it does
The Siemens 3VA1150-5EF36-0CA0 is a SENTRON molded case circuit breaker (MCCB) rated for 50 A continuous at 40 °C, with a 3-pole configuration and a TM240 thermal-magnetic overcurrent release. It's designed for line protection — meaning it sits at the feeder or main distribution point in a panel, not as a motor-protective device. The integrated undervoltage release (UVR) trips the breaker when control voltage drops below a set threshold, which is useful for emergency-stop circuits or undervoltage lockout schemes.
Breaking capacity — what the numbers mean for your fault-current study
This MCCB carries a 187 kA interrupting rating at 240 VAC, dropping to 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V and 690 V. Those are the maximum fault currents the breaker can safely interrupt at each voltage level. For a 480 V panel (common in North America), the 75.6 kA at 440 V is the closest published figure — expect a similar or slightly lower rating at 480 V. The 17 kA at 500 V and 690 V tells you this breaker is not intended for high-voltage distribution; it's a 240–480 V class device.
Current derating — don't size at the 40 °C number alone
The 50 A rating holds flat from 40 °C through 50 °C. At 55 °C it derates to 49 A, at 60 °C to 48 A, at 65 °C to 46 A, and at 70 °C to 45 A. If your panel ambient runs above 50 °C, you need to account for this in your load calculation — a 48 A continuous load at 60 °C ambient would be at the limit. The maximum operating temperature is 70 °C; storage range is -40 °C to 80 °C.
Physical fit and panel integration
Dimensions are 130 mm height, 76.2 mm width (3 inches), and 70 mm depth. The 3-inch width is standard for a 3-pole MCCB in a distribution panelboard — it fits the standard 3-inch mounting centers. Rated insulation voltage is 800 V, which covers the insulation coordination for 480 V and 600 V class systems. Power loss at rated current is 17.1 W maximum, so factor that into your panel thermal budget.