The SENTRON 5SQ2170-2YA04 is a miniature circuit breaker (MCB) from the 5SQ series, designed for branch-circuit overcurrent protection in distribution boards and control panels. Single-pole (1P) construction with a C-curve trip characteristic — the standard choice for moderate inrush loads like small motors, transformers, and lighting banks where the start-up surge exceeds a B-curve's tolerance but doesn't need a D-curve's headroom. Rated 4 A at 240 V AC, 50 Hz, with a 3 kA breaking capacity certified to EN 60898. That 3 kA figure governs its fault-clearing ability at the panelboard's service entrance or subfeed — adequate for residential and light commercial final circuits where the prospective short-circuit current stays under that threshold. The AC/DC voltage rating means it can also switch DC loads up to the same voltage class, though the DC breaking capacity follows a different derating curve; confirm the DC application against the manufacturer's data. Snaps onto a standard DIN rail, occupying one modular width unit. Installation depth is 55 mm.
Panel Fit & Integration
Degree of pollution 3 and overvoltage category III suit it for fixed installations inside an enclosure where conductive contamination is controlled — typical for commercial distribution boards and industrial control panels. The energy limitation class 3 indicates the breaker limits let-through energy during a fault, aiding downstream coordination. No neutral-conductor switching — this is a straight single-pole line-side breaker. For applications requiring switched neutral, pair it with a separate switched-neutral terminal block.