Key ratings and what they mean for your panel
The 5SU9356-7KP40: Rated 40 A at 30 °C, but the current must be derated as ambient temperature rises: 37.6 A at 40 °C, 36.4 A at 45 °C, 34.8 A at 50 °C, and 32.4 A at 55 °C. For a panel running at 50 °C, you effectively have a 34.8 A device — plan your load accordingly. The breaking capacity is 6 kA per EN 60898 (the standard for MCBs/RCBOs in household and similar installations) and 10 kA per IEC 60947-2 (the industrial standard for low-voltage switchgear), so it handles fault currents up to 10 kA in an industrial panel. The C-curve trips at 5–10× In, suitable for motor and lighting loads with moderate inrush.
Mounting and integration
Snaps onto a DIN rail (2 MW width, 36 mm), accepts supply from either top or bottom, and can be mounted in any position. Installation depth is 70 mm; overall depth is 77 mm. Rated IP20 once installed in a distribution board with conductors connected — it is not a stand-alone outdoor device. Pollution degree 2 and overvoltage category III suit it for fixed installations in dry enclosures.