Motor protection circuit breaker, 25 A, Class 10
The Siemens 3RV6021-4DA10 is a SIRIUS motor protection circuit breaker rated for 25 A in AC-3 duty at up to 690 V. The thermal-magnetic overload release is Class 10. Size S0 frame, three-pole, with screw-type terminals accepting 2×(1–2.5 mm²) solid/stranded or 2×(2.5–10 mm²) for the main circuit. Mounts on 35 mm DIN rail per DIN EN 60715 via the screw-and-snap-on fastening method; any mounting position is permitted. The 45 mm width and 96 mm depth fit standard panel layouts — the forward clearance is zero, so it sits flush against the backplane.
Duty cycle and thermal behaviour
Rated for 15 operations per hour at AC-3 duty. Total power loss is 8 W typical. Shock resistance tested at 25 g / 11 ms per IEC 60068-2-27, and surge voltage withstand is 6 kV — both figures confirm the breaker holds its settings and doesn't nuisance-trip under mechanical or electrical transients common in industrial refrigeration compressor starts.