The Siemens SENTRON 5SU9654-7KK20 is a 2-pole RCD-operated circuit breaker (RCBO) combining overcurrent protection and residual current detection in one 36 mm wide, 77 mm deep module — 2 modular width units on a DIN rail, mountable in any position, with supply feed from top or bottom.
Derating and ambient temperature
At 40 °C it derates to 18.8 A, at 50 °C to 17.4 A, and at 55 °C to 16.2 A — so in a warm enclosure (common in packed panels) the connected load must be sized accordingly.
Two modular-width units (36 mm) snap onto a DIN rail; the 77 mm depth fits standard enclosures. Installation depth is 70 mm. Degree of pollution 2 and IP20 when installed in a distribution board with connected conductors.