Siemens 3VM9401-0WG40 Thermal-Magnetic Molded Case Circuit Breaker

The primary function is to provide reliable protection for electrical circuits against overcurrents, specifically overloads and short circuits. It acts as an automatic safety switch, interrupting electricity flow when fault conditions are detected, thereby preventing damage to equipment and safeguarding against hazards like fires and electrical shocks.

The thermal element uses a bimetallic strip that heats up and bends under sustained overload conditions, causing a delayed trip. The magnetic element uses an electromagnet that reacts instantly to sudden, high-current surges typical of short circuits, tripping the breaker within milliseconds. This dual action ensures protection against both gradual overloads and rapid short circuits.

Key advantages include dual protection capability, fixed trip settings (TM210) that simplify installation and reduce human error, compact design for easy integration, and Siemens' reputation for reliability and durability in demanding industrial environments.

This circuit breaker is widely used in power distribution systems for industrial facilities, commercial buildings, and infrastructure projects. Applications include protecting main distribution boards, sub-distribution panels, feeders, and critical industrial machinery such as motors and pumps.

Yes, it can be reset after it trips, provided the fault condition has been resolved. The breaker features a manual operating handle that allows it to be switched back on. It is crucial to identify and rectify the cause of the trip before resetting to prevent further damage.