Siemens 3RV2321-4DC10 Motor Protection Circuit Breaker

Siemens 3RV2321-4DC10 is a S0‑size motor starter protector from the SIRIUS 3RV2 family, designed to form starter combinations on a DIN rail with screw‑terminal connections. It provides overload protection and interruption for small to mid‑size motors with a rated current of 25 A and a short‑circuit release capability of 325 A, making it suitable for motor startup protection in practical control panels. The device is rated for 690 V AC insulation up to pollution class 3, withstands surge voltages up to 6 kV, and operates in ambient temperatures from -20 to +60 C. Weight is 0.365 kg, and heat dissipation is about 10.5 W in hot operation (3.5 W per pole). The unit is built for high cycling endurance, with main and auxiliary contacts typically rated for up to 100,000 operating cycles, and it supports standard switching capacity in motor starter circuits. The suffix 4DC10 denotes a DC release variant compatible with DC‑coil control logic, and the product is documented for use in Siemens’ motor starter protectors catalog and Industry Mall listings. Compact and rugged, this MPCB fits compact panel layouts and is suitable for protection schemes that combine with contactors to guard motors during start and run, while meeting RoHS and related compliance expectations for modern industrial equipment.