What this MCCB delivers
The Siemens SENTRON 3VA2040-5KQ36-0AA0 is a 3-pole molded case circuit breaker rated for 40 A continuous current across the full operating temperature range from -25 °C to 70 °C — no derating needed up to 70 °C, which simplifies panel design in warm enclosures. Breaking capacity hits 187 kA at 240 V AC, 121 kA at 415/440 V, and 75.6 kA at 500 V — numbers that put this squarely in the high-fault category for industrial distribution, meaning it can clear a bolted fault upstream of a 2000 kVA transformer without cascading.
The breaker includes a communication function for integration with energy management or remote monitoring systems — useful when you need trip data or load profiles without a separate metering block. Ground-fault monitoring uses summation current formation on the L-conductor, so it catches leakage without a separate GFCI module.
Protection and control features
Designed for line protection (cable and busbar protection), not motor protection — the adjustable thermal-magnetic or electronic trip unit is set for overcurrent and short-circuit on feeders. No undervoltage release fitted as standard, and no voltage trip trigger — if UVR is required for your safety circuit, it needs to be added as an accessory. Maximum power loss is 2.2 W — negligible for thermal budget in a sealed panel, but worth noting if you're packing multiple breakers in a small enclosure.