What this MCCB delivers
The Siemens 3VA1140-5EF32-0BH0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, carrying 40 A continuously at 40 °C ambient — no derating needed until you cross 55 °C, where it drops to 39 A, and 37 A at 70 °C. That 70 °C operating ceiling is the same as the maximum ambient the breaker sees in a hot panel; the storage range of -40 to 80 °C covers transit and warehouse conditions. The 187 kA breaking capacity at 240 VAC is the headline number — it tells you this breaker can safely interrupt a fault current up to that level without welding its contacts or venting plasma into the enclosure. At 415 V it still handles 121 kA, at 440 V it's 75.6 kA, and at 500/690 V it holds 17 kA. That's a high-interrupting-capacity (HIC) class MCCB, sized for installations where the available fault current is substantial — think industrial switchboards, transformer secondaries, or large motor control centers. The 3-pole design fits three-phase circuits. An undervoltage release (UVR) is built in — if the control voltage drops below its dropout threshold, the breaker trips, protecting downstream equipment from brownout conditions or restarting on an unstable supply. The auxiliary switch complement is 2 auxiliary switches plus 1 trip alarm switch (HQ), giving you status feedback for a PLC or annunciator panel. The basic switch core is 3VA11405EF320AA0, and the insulation voltage is rated at 800 V, which covers most 400/480/690 V systems with margin.
Panel fit and thermal reality
Mounting dimensions: 130 mm tall, 76.2 mm wide, 70 mm deep. That 70 mm depth is the key number for enclosure depth — it means this MCCB fits a standard 200 mm deep panel with room for wiring and a rear gland plate. The 76.2 mm width (3 inches) matches the footprint of other SENTRON 3VA1 frame breakers, so swapping within the family is a direct mechanical fit. Power loss is 13.3 W maximum — that's the heat the breaker dissipates at full rated current. In a sealed enclosure with multiple breakers, that heat adds up; the thermal derating curve above 55 °C is the guide for grouping.