63 A C-curve MCB for high-current branch protection
The Siemens 5SY7563-7 is a 63 A C-curve miniature circuit breaker from the SENTRON 5SY7 series, configured 1P+N (2-pole) for single-phase AC branch circuits. Breaking capacity is rated 15 kA per EN 60898 and 20 kA per IEC 60947-2, with a DC rating of 15 kA at 72 V per IEC 60947-2. That 20 kA figure under the industrial standard means it can interrupt high fault currents typical in distribution panels downstream of a transformer — the 15 kA residential/light-commercial rating is the lower bound for domestic boards. Energy limiting class 3 keeps let-through energy low, which protects downstream wiring and devices during a short-circuit event.
Panel fit and wiring constraints
At 36 mm wide (2 width units) and 76 mm deep, this breaker occupies two standard DIN-rail slots. Terminals accept solid or stranded conductors from 0.75 to 35 mm² — that 35 mm² upper end is unusual for a 63 A MCB and lets you land the incoming feed with a single large conductor rather than paralleling smaller wires. Combined top and bottom terminals are both sealable, which matters for panel builders who need to lock out adjustments after commissioning. Touch protection is built in (IP20 with conductors connected), so accidental contact during troubleshooting is protected against.