What this breaker brings to a panel
The Siemens 5SL6203-7 is a 2-pole SENTRON miniature circuit breaker rated at 3 A with a C-curve trip characteristic and a 6 kA breaking capacity per both EN 60898 and IEC 60947-2. The 2-pole design makes it a straight fit for single-phase 230/400 V circuits or two-phase 400 V loads — common in lighting panels, small distribution boards, or HVAC equipment.
The 3 A rating is low for a 2-pole MCB — think lighting strips, control transformers, or small resistive loads where you want tight overcurrent protection without nuisance trips. At 6 kA SCCR it interrupts faults up to that level safely; in a panel fed by a transformer with a higher available fault current, you'd need a current-limiting upstream breaker or a higher-rated MCB like the 5SL4363-7 (10 kA). The 2 MW width means it occupies two 18 mm positions on the DIN rail — check your enclosure fill factor if you're swapping from a single-pole device.
Snaps onto DIN rail, any mounting position. Overall dimensions: 36 mm wide (2 MW), 90 mm high, 76 mm deep. Installation depth is 70 mm.