Siemens SENTRON 5SY3020-6KV — B-curve 20 A 1+N-pole MCB, 4.5 kA
The Siemens SENTRON 5SY3020-6KV is a miniature circuit breaker (MCB) with a B tripping characteristic, rated 20 A at 230 V AC, and a breaking capacity of 4.5 kA per EN 60898.
What the B-curve and 20 A rating mean for your circuit
At 20 A it protects 2.5 mm² copper wiring in standard 230 V single-phase circuits. The 4.5 kA breaking capacity is adequate for domestic and light commercial service-entrance fault levels; for industrial panels with higher prospective short-circuit current, a 6 kA or 10 kA rated MCB (like the 5SY6020-7KL) would be required.
Panel fit — DIN-rail footprint and neutral switching
Its 70 mm installation depth is the same as the 5SY3025-7KL and 5SY6020-7KL peers, so it drops into an existing SENTRON distribution board without enclosure or busbar realignment. The 1+N-pole format means the neutral conductor is switched through the breaker — verify that the downstream neutral bar is not bonded elsewhere when using this as the main incoming device.