The breaker holds the unit on the grid for feeder circuits in industrial switchboards, motor control centers, or building power distribution, provided the available fault current stays within the published breaking capacities.
Breaking capacity — the real number depends on your system voltage
This MCCB delivers 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V. At 690 V the breaker still clears 17 kA, which is adequate for many 690 V motor circuits but not for a main tie near a utility transformer.
Current derating — the 40 A rating holds to 50 °C
At 55 °C it derates to 39 A, at 65 °C to 38 A, and at 70 °C to 37 A.
Physical fit and auxiliary switch configuration
The breaker measures 130 mm high, 76.2 mm wide, and 70 mm deep — standard 3-pole MCCB footprint for the 3VA frame size. The auxiliary switch signals the open/closed state; the trip alarm switch indicates a trip from the overcurrent release, not from manual opening. Both are wired to the terminal block on the front face.