Siemens 5SY7325-8CC — 3-pole D-curve MCB for motor and industrial loads
The Siemens 5SY7325-8CC is a 3-pole miniature circuit breaker from the SENTRON 5SY7 series, rated 25 A at 400 V AC with a D tripping characteristic. The 25 kA breaking capacity per IEC 60947-2 gives fault-clearing headroom in industrial panels with high available fault current; the UL 1077 / CSA C22.2 No. 235 rating is 5 kA, so verify the SCCR if the assembly is listed under North American codes. Tightening torque is 2.5–3.5 N·m.
The 5 kA rating under UL 1077 / CSA C22.2 No. 235 is a supplementary-protector classification; if the panel requires a UL 489 listed branch-circuit breaker, this part may not meet that listing. Overvoltage category III (distribution level) confirms it is rated for fixed-installation use downstream of the main service entrance. The D tripping characteristic (10–20× In) is the key selection parameter for motor feeders and inductive loads. At 25 A, the magnetic trip threshold is 250–500 A, which rides through the inrush of a 7.5 kW motor (DOL start) without opening. For resistive loads or general-purpose distribution, a C-curve sibling would be a better fit — the D curve is deliberately slower to clear low-level overloads.
The sealable feature (padlockable toggle) allows lockout/tagout without additional accessories. Touch protection is integral (IP20 with connected conductors), so no finger-safe covers are needed on the terminals in a closed panel.