63 A, 4-pole, C-curve — what it means on the panel
The Siemens 5SJ6463-7 is a SENTRON 5SJ6 miniature circuit breaker rated for 63 A continuous at 400 V AC, 4-pole, with a C tripping characteristic. The C-curve means it holds through inrush up to 5–10× rated current before tripping magnetically — typical for motor, transformer, or lighting panel feeder circuits where the start-up surge would nuisance-trip a B-curve.
Mounting and wiring — snaps into a 4-module DIN slot
Terminals accept 1.5 mm² minimum to 2.5 mm² maximum conductor cross-section, which is the sweet spot for 63 A branch circuits in copper. Touch protection is built into the terminals, so live parts are shielded when the breaker is wired.
Rated for 50 Hz supply, overvoltage category III, and energy limiting class 3. Ambient operating conditions include periodic exposure to +55 °C and up to 95% humidity, with vibration resistance tested to 50 m/s² at 25–150 Hz and 60 m/s² at 10–150 Hz per IEC 60068-2-6. Mechanical service life is 20 000 switching cycles typical — that's a solid 20+ years in normal distribution duty.