What this 800 A MCCB brings to the panel
The Siemens 3VA2580-7HL42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 800 A continuous current across a wide ambient range — it holds the full 800 A from 40 °C up to 60 °C, then derates to 767 A at 65 °C and 703 A at 70 °C. That flat thermal curve means you don't lose headroom in a warm enclosure unless the internal ambient pushes past 60 °C. This is a line-protection breaker (not a motor-protection or generator breaker), so the trip curves are set for feeder and distribution duty.
Breaking capacity — the real number for selectivity
At 240 V it interrupts 440 kA; at 415 V and 440 V it's 242 kA; at 500 V it's 187 kA; at 690 V it's 73.5 kA. Those are the numbers you need for arc-flash incident-energy calculations and for coordinating with upstream gear.
Dimensions: 280 mm wide, 320 mm high, 120 mm deep. That 280 mm width is the panel cutout driver — it's a wide-frame MCCB, not a compact 3VA2 frame. The trip indicator is also absent. If you need shunt trip, UVR, or comms, you add external accessories via the accessory slots — the base breaker is a straight line-protection device.