What this RC unit does for a 5SL4 panel
The Siemens SENTRON 5SM2323-6 is a residual-current (RC) unit designed to pair with a 5SL4 miniature circuit breaker, making a combined RCBO in a two-module-wide package. It's a 2-pole, type A device rated at 40 A and trips on a 30 mA fault current — the standard for personal protection in residential and commercial final circuits. The rated insulation voltage is 460 V, and it's built for 50 Hz systems only.
DIN rail fit and panel space
The installation depth matches the width at 70 mm, so it sits flush in a standard distribution board. Rated IP20 with conductors connected, which is the norm for enclosed panels.
Temperature derating — real-world current capability
The 40 A rating is at reference conditions. In a warm panel, it drops: at 40 °C it's 37.2 A, at 45 °C it's still 37.2 A, at 50 °C it's 36 A, at 55 °C it's 34.8 A, at 60 °C it's 34 A, at 65 °C it's 33.2 A, and at 70 °C it's 32 A.