The Siemens 3RV2021-4FA10-ZX95 is a SIRIUS motor-protection circuit breaker designed for motor loads. It combines a CLASS 10 thermal-magnetic trip curve with phase failure detection, so it catches a lost phase before the winding temperature climbs — the operator will find the bug at 2 a.m. if you skip that protection.
Terminal screws for main contacts are M4; wire range 2x 1–2.5 mm² solid or stranded, or 2x 2.5–10 mm². Clearance: 70 mm above and below, 30 mm at the sides, zero forward or backward. Mount in any position.
