RCD-operated circuit breaker — 63 A, Type A, C-curve
The Siemens 5SU9156-7KK63 is a SENTRON RCBO — an RCD-operated circuit breaker combining overcurrent and residual-current protection in a single 36 mm wide (2 width units) module. It switches a 63 A rated current at 30 °C, with the C tripping characteristic handling moderate inrush from motor or lighting loads. The Type A residual-current detection catches both sinusoidal AC faults and pulsating DC fault currents up to 30 mA — the standard choice for single-phase circuits feeding electronics, appliances, or small drives. The 1P+N pole configuration protects the live conductor while switching the neutral; the protected pole is identified on the nameplate.
Thermal derating — what the 63 A rating actually delivers
At 40 °C the device is rated 59.22 A; at 45 °C it drops to 57.33 A; at 50 °C it is 54.81 A; at 55 °C it is 51.03 A. For a 63 A circuit in a warm enclosure, size the load at the 45 °C figure (57.33 A) unless you have forced ventilation.
Panel fit and wiring — 36 mm wide, 70 mm installation depth
The module is 36 mm wide (2 width units), 90 mm tall, with a total depth of 77 mm and an installation depth of 70 mm — the difference is the front projection of the toggle and test button. Touch protection is built in — no exposed live parts after installation.