The Siemens 5SY5225-7 is a SENTRON miniature circuit breaker (MCB) with a C tripping characteristic, designed for 2-pole (2P) operation. It provides overcurrent and short-circuit protection for branch circuits in distribution boards and control panels, rated for universal current (AC/DC) at 400 V AC (single- and multi-phase) and 440 V DC. The C-curve (tripping between 5× and 10× In) suits moderate inrush loads like motor starters, transformers, and lighting banks where a B-curve would nuisance-trip but a D-curve would delay too long.
Breaking capacity and selectivity
Rated breaking capacity is 10 kA per EN 60898-2 and 15 kA per IEC 60947-2 at DC. That 15 kA DC rating is the figure to check for DC bus protection in drives or UPS cabinets — the EN 60898-2 number covers AC branch circuits. The 2-pole design allows simultaneous opening of both poles, which is essential for DC circuits (observe DC polarity per the manufacturer) and for multi-phase AC loads where a single fault must not leave one phase energized.
Lifecycle and sourcing
Current-production part — no end-of-life notification on record. The 5SY5225-7 is sourced and quoted to order through independent distribution; availability and current pricing are confirmed at quote time against an RFQ. For a BOM freeze or line-down spare, this MCB is a standard catalog item with no impending phase-out.
Integration and mounting
Snaps onto DIN rail via the quick-assembly system; occupies 2 modular width units (36 mm). Mounting position is any. Depth behind panel is 70 mm (installation depth), overall depth 76 mm. Combined terminals top and bottom accept copper conductors. IP20 with connected conductors — suitable for enclosed distribution boards, not for wet environments. Halogen-free and silicon-free construction matters for clean-room or high-reliability installations where outgassing can contaminate contacts or optics.