MCB for panel builders — C-curve 4 A, 1P+N, 50 kA
The Siemens SENTRON 5SY8504-7 is a 2-pole miniature circuit breaker (1P+N) with C-curve tripping characteristic, rated 4 A at 250 V AC single-phase. The 1P+N design switches the neutral, so you get full isolation on both poles in one 36 mm-wide module.
At 50 kA per IEC 60947-2 (AC) and 15 kA per the same standard at 72 V DC, this breaker handles fault levels typical of main distribution boards in industrial environments. The C-curve (5–10× In) suits motor and transformer inrush without nuisance tripping. For UL 1077 recognition, the interrupting rating is 5 kA — confirm your panel's SCCR against that figure if the job falls under North American code.
Ambient range spans –40 °C to 75 °C, but note the derating: at 50 °C the continuous current drops to 3.88 A, at 55 °C to 3.75 A.
Material compliance and vibration
Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz. Sealable terminals allow tamper-proofing after commissioning.