Siemens 5SY4480-6 SENTRON — 4-pole B-curve MCB for panel builders
The Siemens 5SY4480-6 is a SENTRON miniature circuit breaker in a 4-pole (4P) configuration with a B tripping characteristic, rated 400 V AC and 60 V DC. It carries a 10 kA breaking capacity per IEC/EN 60898-1 and 15 kA per IEC/EN 60947-2 at DC, with a UL/CSA rating of 5 kA per UL 1077 and CSA C22.2 No.235. The 72 mm width (4 modular units) snaps onto a DIN rail via the quick assembly system and accepts any mounting position — no derating for horizontal or upside-down installs. This is a current-production part (lifecycle stage: active). The B-curve trips between 3 and 5 times rated current, making it the go-to choice for resistive and general-purpose loads in mechanical engineering and industrial panels — not motor circuits, where a C or D curve would handle the inrush.
Breaking capacity and dual-standard rating
The 10 kA rating under IEC/EN 60898-1 covers the residential and light commercial fault-current range; the 15 kA DC rating under IEC/EN 60947-2 gives it headroom for industrial DC bus protection. The 5 kA UL 1077 / CSA C22.2 No.235 rating means it qualifies as a supplementary protector in North American panels — not a branch-circuit rated breaker under UL 489, so spec it accordingly if your BOM calls for UL 489 listing. Pollution degree 3 and overvoltage category III suit it for fixed-installation environments where conductive dust or humidity is present. The IP20 rating (with conductors connected) is standard for enclosed distribution boards — no washdown rating, so keep it behind a gland plate.
Mounting and panel integration
Four modular width units (72 mm) on a standard DIN rail. The quick assembly system clips in without tools; combined terminals top and bottom accept copper conductors. Installation depth is 70 mm, overall depth 76 mm — factor that into your enclosure fill calculation. The sealable design lets you lock the toggle position after commissioning to prevent unauthorized switching. Ambient temperature range spans -40 °C to 75 °C, with humidity derating above 55 °C (95% RH at 55 °C, down to 35% at 75 °C). Vibration resistance per IEC 60068-2-6: ±1 mm at 5–25 Hz, 50 m/s² at 25–150 Hz — fine for machine-mounted panels but not for direct engine-mount without additional damping.