SENTRON 5SY4205-8CC11 — 2-pole D-curve MCB, 0.5 A, railway-rated
The Siemens SENTRON 5SY4205-8CC11 is a 2-pole miniature circuit breaker with D tripping characteristic, rated 0.5 A at 400 V AC. Rated for 400 V AC line-to-line and 72 V DC maximum, this 2P unit switches both poles simultaneously — no neutral switching. The multi-phase rating extends to 440 V AC, covering 400 V systems with tolerance. IP20 applies only with connected conductors, so the busbar stabs and terminals are protected once wired.
The D characteristic defines magnetic trip between 10× and 20× In (5 A to 10 A for this 0.5 A unit). That delay lets through the magnetizing inrush of a small transformer or the locked-rotor spike of a fractional-horsepower motor without opening.
Termination and panel integration
Width is 36 mm (2 width units,), occupying two 18 mm module spaces on the rail.