What this MCB is and what the ratings mean for your panel
The Siemens 5SY4102-6CC is a 1-pole miniature circuit breaker from the SENTRON family, designed for branch-circuit protection in industrial control panels. The B tripping characteristic means it trips at 3 to 5 times rated current — suited for resistive and lighting loads where inrush is low, rather than motor circuits that need a C or D curve. Breaking capacity is 10 kA per EN 60898, which covers most industrial distribution boards up to that fault level; for UL 1077 / CSA C22.2 No. 235 applications the rating is 5 kA. The 18 mm width (1 modular unit) snaps onto standard DIN rail, and the quick assembly system lets you gang multiple poles without extra hardware.
Installation and environmental fit
Mounts in any position on DIN rail; the 70 mm installation depth leaves clearance behind the panel door. IP20 with connected conductors — standard for enclosed distribution boards, not for wet or washdown zones. Pollution degree 3 and overvoltage category III suit fixed industrial installations where transient overvoltages are expected. Temperature range of -40 to 75 °C covers unheated plant rooms and outdoor enclosures, but note the derating curve: at 55 °C humidity must stay below 95%, at 70 °C below 55%, and at 75 °C below 35%. Combined terminals top and bottom accept copper conductors without needing separate neutral bars for the single-pole variant.
Compliance and documentation
Rated for AC 50/60 Hz up to 400 V (440 V multi-phase and single-phase). DC rating is 72 V maximum. Vibration resistance per IEC 60068-2-6: ±1 mm at 5 to 25 Hz, 50 m/s² at 25 to 150 Hz. Mechanical service life is 10 000 operating cycles typical. The design is halogen-free and silicon-free, which matters for sensitive environments like semiconductor fabs or medical device production where outgassing contaminants must be avoided. Sealable design allows lockout/tagout. Energy limitation class 3 means it limits let-through energy effectively during a fault.