6 A, 4-pole, Char. A — what the ratings mean for fit
The 5SY4406-5 is a 4-pole miniature circuit breaker from the Siemens SENTRON 5SY4 series, rated 6 A at 400 V AC with tripping characteristic A. The 6 A rating sets the continuous current ceiling for the protected circuit; the characteristic A curve trips between 2 and 3 times rated current (12–18 A), making it the fastest standard trip curve — suited for protecting semiconductor circuits, control transformers, or sensitive electronic loads where even a brief overcurrent could damage downstream components. Breaking capacity is rated 10 kA per EN 60898, 35 kA per IEC 60947-2, and 15 kA at DC per IEC 60947-2. The 35 kA IEC figure gives selectivity headroom in industrial panels where the upstream device may have a higher prospective fault current; the 10 kA EN rating is the standard domestic/commercial coordination value. For UL 1077 applications the interrupting rating is 5 kA at AC.
DIN-rail footprint and wiring constraints
Occupies 4 width units (72 mm) on a DIN rail, with a depth of 76 mm and height of 90 mm. The mounting position is unrestricted — the breaker can be installed horizontally or vertically without derating. Installation depth is 70 mm, so the breaker projects 6 mm beyond the rail for wiring access. Accepts solid or stranded conductors from 0.75 mm² up to 35 mm² at both top and bottom combined terminals. The wide cross-section range covers everything from control-circuit signal wiring (0.75 mm²) to main feeder tails (35 mm²) without needing adapters. Terminal sealable and touch-protected per the product features.
Ambient range and environmental ratings
Rated for ambient temperatures from -40 °C to +70 °C, with storage range matching the same -40 to +75 °C. The wide thermal envelope suits unheated enclosures, outdoor cabinets, or process areas near ovens. Humidity tolerance is specified as 95% at 55 °C, derating to 35% at 75 °C — relevant for tropical or washdown environments where condensation may occur. IP20 protection with connected conductors — the breaker itself is finger-safe, but the enclosure must provide additional ingress protection if the panel is in a wet or dusty location. Halogen-free and silicon-free construction, which matters for clean-room, semiconductor fab, or aerospace applications where outgassing or corrosive byproducts are a concern.