The Siemens SENTRON 5SL6210-6BB is a 2-pole miniature circuit breaker with a B tripping characteristic, rated at 10 A at 30 °C and 6 kA breaking capacity per EN 60898 and IEC 60947-2.
For a domestic or light commercial distribution board fed by a typical 100 kVA transformer (prospective short-circuit current usually under 6 kA at the sub-distribution level), this rating provides adequate fault clearance. The B-curve (3–5× In) avoids nuisance tripping on cable charging currents while still protecting 1.5–2.5 mm² copper wiring against overload. Derating is explicit: at 40 °C the breaker carries 9.24 A, at 45 °C it drops to 8.8 A, and at 55 °C it is 7.96 A. If the panel ambient exceeds 30 °C — common in a sealed enclosure or a summer attic installation — size the upstream protection or load accordingly. The 2-pole design (2P) switches both phase conductors but does not switch the neutral (no neutral conductor switching). Physical fit: 36 mm wide (2 modular width units), 90 mm tall, 76 mm deep with an installation depth of 70 mm.