What this breaker carries and where it fits
The Siemens SENTRON 3VA1150-4EF36-0KA0 is a 3-pole molded case circuit breaker rated for 50 A continuous current (Iu) at 40 °C through 50 °C, with a slight thermal derating curve above that: 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. The TM240 overcurrent release provides fixed thermal-magnetic protection, and the breaker carries a shunt trip (STL) auxiliary release (order code 3VA9688-0BL33 for the integrated auxiliary trip). Rated insulation voltage is 800 V (Ui). This is a line-protection version — not a motor-protection or ground-fault variant. It has no undervoltage release, no communication function, no phase failure detection, and no auxiliary contact. The front face carries an IP40 rating, so it is suited for installation inside a panel or enclosure where dust ingress is limited.
Interrupting capacity — what the ratings mean for selectivity
The 3VA1150-4EF36-0KA0 delivers interrupting capacities of 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. At 415 V — a common industrial distribution level — that 75.6 kA gives substantial headroom above most transformer-fed fault currents, simplifying coordination with downstream breakers. At 690 V the capacity drops to 11.9 kA, so verify the available fault current if this breaker is applied on a 690 V system.
Mechanical integration — panel footprint
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. The 76.2 mm width (roughly 3 inches) is the standard 3-pole MCCB footprint for SENTRON 3VA frames at this rating. The 70 mm depth means it clears typical 200 mm deep enclosures with room for rear bus connections. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.