What this MCCB carries — and what it doesn't
The Siemens SENTRON 3VA1080-4ED42-0KH0 is a 4-pole molded case circuit breaker (MCCB) rated at 80 A at 40 °C, designed for line protection in distribution panels. Breaking capacity hits 121 kA at 240 VAC — enough for high-fault service-entrance or sub-distribution boards where upstream transformer capacity is substantial. The 800 V rated insulation voltage means it handles 690 V line-to-line systems without derating the isolation gap. No communication module, no ground-fault monitoring, no undervoltage release on this variant — it's a straight thermal-magnetic breaker with a shunt trip (STL) and two auxiliary switches plus a trip alarm switch.
Breaking capacity across the voltage range
At 415 VAC the 3VA1080-4ED42-0KH0 interrupts 75.6 kA; at 440 VAC it's 52.5 kA; at 500 V and 690 V it holds at 11.9 kA (–). That steep drop above 440 V is typical for a compact-frame MCCB — the arc extinction energy scales with voltage. For a 690 V wind-turbine or mining feeder, the 11.9 kA figure is the one that governs the SCCR study, not the 240 V headline.
Thermal derating — don't assume 80 A at every panel temp
The 80 A rating holds from 40 °C through 50 °C (–). At 55 °C it drops to 78 A; at 65 °C to 75 A; at 70 °C to 74 A (–). If this breaker sits next to a transformer or drive in a sealed enclosure, use the 70 °C column — that 74 A continuous limit is the real-world figure for the BOM. Operating ambient range is -25 °C to +70 °C; storage range is -40 °C to +80 °C.
Dimensions and panel fit
Footprint: 101.6 mm wide, 130 mm tall, 70 mm deep (–). That 70 mm depth is the dimension that matters for gland-plate clearance — standard 80 mm deep enclosures leave 10 mm for wiring behind the breaker. The 101.6 mm width (4 inches) means it occupies four 25 mm DIN-module positions. Maximum power loss is 19.2 W — account for that in the enclosure thermal budget, especially when grouping multiple breakers.