What it is and what the ratings mean
The Siemens 5SL6514-8CC is a miniature circuit breaker (MCB) rated 230 V with a 6 kA breaking capacity, 1+N-pole configuration, D tripping characteristic, and a 0.3 A rated current. The D-curve means it tolerates high inrush currents — typically 10 to 20 times the rated current before tripping magnetically — making it the right choice for transformer, motor, or capacitive loads where the startup surge would nuisance-trip a B or C curve breaker. The 1+N-pole format switches both the line and neutral, with overcurrent protection on the line pole only; the neutral pole is switched but not protected. The 6 kA breaking capacity at 230 V is sufficient for most residential and light commercial distribution boards where the prospective short-circuit current stays under that level.