What it is and what it does
The Siemens SENTRON 3VA1140-5EF36-0HH0 is a 3-pole molded case circuit breaker (MCCB) rated for 40 A continuous current at 40 °C ambient, designed for line protection in distribution panels. Its interrupting capacity hits 187 kA at 240 V AC and 121 kA at 415 V AC — numbers that matter when you need fault clearance without upstream breaker cascade. The 800 V rated insulation voltage tells you it's built for 480 V and 600 V class systems with headroom.
What the ratings mean for fit
The 40 A rating holds flat from 40 °C through 50 °C, then derates to 39 A at 55 °C and 37 A at 70 °C — so in a warm panel you lose 3 A off the nameplate. The interrupting curve drops sharply above 440 V: 75.6 kA at 440 V, then 17 kA at 500 V and 690 V. If your fault current at 480 V exceeds 17 kA, this breaker won't clear it — you need a higher-rated frame. The 3-pole design with shunt trip (STL) and two auxiliary switches plus a trip alarm switch (HQ) means it can signal a remote PLC on fault and be remotely tripped for emergency stop circuits.
Panel integration and mounting
Mounts on a DIN rail or direct panel — the 76.2 mm width (3 inches) and 130 mm height (5.12 inches) fit standard MCCB slots in most distribution boards. Depth is 70 mm (2.76 inches), leaving room for cable bending radius behind the breaker. The shunt trip and auxiliary switches are factory-fitted, so no field assembly of accessories. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C — fine for unheated electrical rooms.