SENTRON 5SQ2270-0KA20 — 2-pole C-curve MCB at 20 A
The Siemens SENTRON 5SQ2270-0KA20 is a 2-pole miniature circuit breaker (MCB) with a C tripping characteristic, rated 20 A at 400 V AC, 50 Hz. The C-curve (5–10× In) suits inductive loads like small motors, fluorescent lighting banks, and transformer-fed circuits where inrush would nuisance-trip a B-curve. Installation depth is 55 mm, so it fits standard distribution boards without crowding the wiring gutter. Overvoltage category 3 and energy limiting class 3 mean it's designed for fixed-installation downstream of the utility meter, not for portable equipment.
Panel fit and compliance notes
The 55 mm depth leaves clearance for wiring ducts and busbar systems in standard 100 mm deep enclosures. Neutral conductor switching is integral, so no external link is needed for the switched neutral pole; this simplifies wiring in TN-S or TT systems where both phase and neutral must be isolated.