The Siemens 5SY7420-8CC is a SENTRON 4-pole miniature circuit breaker with a D tripping characteristic, rated 20 A at 400 V AC. It breaks 25 kA per IEC 60947-2, which means it safely interrupts high fault currents in industrial distribution panels without cascading upstream — a key spec for selectivity coordination. For UL 1077 and CSA C22.2 No. 235 installations, the interrupting rating is 5 kA.
Panel fit and wiring
Mounts on a DIN rail via the quick-assembly system, occupying 4 width units (72 mm). The installation depth behind the panel is 70 mm; overall depth is 76 mm. Terminals accept solid or stranded conductors from 0.75 to 35 mm², torqued to 2.5–3.5 N·m. Combined terminals at top and bottom simplify busbar and ring-lug connections. Any mounting position is allowed.
Sourcing and availability
Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing confirmed at quote time. No last-time-buy or phase-out notice applies.