Breaking capacity and what it means on your line
This breaker carries a 10 kA interrupting rating per IEC/EN 60898-1, and 20 kA per IEC 60947-2 at 400 V AC. For DC circuits, it's rated 15 kA at 60 V (72 V max) per IEC 60947-2, and under UL 1077 it's listed for 5 kA. The dual rating means it's built for IEC-spec panels globally but also carries the UL mark for North American machinery control panels.
Panel fit and environmental tolerance
The 5SY4218-7 occupies 2 modular width units (36 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. It mounts in any position, and the terminals accept top and bottom comb busbars for easy distribution. Temperature range runs from -40 °C to 75 °C, with humidity derating above 55 °C (95% at 55 °C, down to 35% at 75 °C). That covers most plant-floor environments, including unheated warehouses and outdoor-rated enclosures. IP20 with conductors connected — standard for inside a closed panel.