What this MCCB is and what it carries
This is a Siemens SENTRON 3VA1580-7GF42-0AA0 molded case circuit breaker (MCCB) rated for 800 A continuous current (Iu) in a 4-pole configuration, built for line protection duty. The TM240 thermal-magnetic release handles the overload and short-circuit trip curve, with an adjustable short-circuit pickup up to 8000 A. At 240 V it interrupts 440 kA — that is the headline breaking capacity for this frame — and still delivers 242 kA at 415/440 V, 154 kA at 500 V, and 73.5 kA at 690 V. The 800 A rating holds at ambient temperatures up to 50 °C; above that it derates to 780 A at 55 °C, 761 A at 60 °C, 741 A at 65 °C, and 722 A at 70 °C.
Where it fits and how it mounts
The 3VA1580 frame measures 320 mm high, 280 mm wide, and 120 mm deep — a large-frame MCCB sized for main or feeder breaker positions in LV switchboards and distribution panels. The 4-pole construction with 100% N-conductor protection makes it suitable for three-phase plus neutral systems where the neutral is not derated. IP40 on the front face means it is protected against tools and wires ≥1 mm but not sealed against water; install it inside a cabinet, not in a washdown zone.
What the TM240 release means for coordination
The TM240 designation indicates a thermal-magnetic trip unit with a continuous current rating of 800 A. The thermal element provides overload protection with an inverse-time characteristic; the magnetic element handles short-circuit protection with an adjustable pickup range up to 8000 A. For selectivity studies, the 440 kA interrupting rating at 240 V gives substantial headroom upstream of downstream breakers. The 800 V rated insulation voltage (Ui) supports 690 V line-to-line systems comfortably.