What it is and what it does
The Siemens 5SY6350-6 is a SENTRON miniature circuit breaker (MCB) in a 3-pole configuration with a B tripping characteristic. It protects branch circuits against overload and short-circuit in final distribution panels and industrial control cabinets. The B-curve trips between 3 and 5 times rated current, making it the standard choice for resistive and general-purpose loads where inrush is low — lighting, small transformers, control circuits. Rated at 400 V AC with a breaking capacity of 6 kA per IEC/EN 60898-1 and 10 kA per IEC 60947-2, it also carries a 5 kA rating under UL 1077. The 54 mm width (3 modular units) snaps onto a DIN rail via the quick-assembly system and can be mounted in any position. IP20 with connected conductors is the protection class — standard for enclosed panel use, not for wet or washdown locations.
Lifecycle and sourcing reality
Compliance documentation is straightforward: the 5SY6350-6 carries IEC/EN 60898-1 and IEC/EN 60947-2 approvals plus UL 1077 and CSA C22.2 No.235. It is halogen-free and silicon-free, which matters for panels in clean-room or sensitive electronics environments where outgassing is a concern.
Panel integration notes
Depth is 76 mm (70 mm installation depth behind the panel face), height 90 mm, width 54 mm — three 18 mm modular units on the DIN rail. The combined terminal at top and bottom accepts both busbar and conductor connections without extra adapters. Sealable design allows lockout/tagout for maintenance isolation. Ambient temperature range is -40 °C to 75 °C, with derating for humidity: max 95% RH at 55 °C, dropping to 35% at 75 °C. Pollution degree 3 and overvoltage category III mean it is rated for industrial environments with conductive contamination and transient overvoltages — no need for additional surge protection upstream in most panels.