Siemens Industrial Controls 3RV2901-1A Auxiliary Switch 1-NO 1-NC

The Siemens Industrial Controls 3RV2901-1A Lateral Auxiliary Switch is an add-on contact block used in motor control and protection systems. It is designed to mount on rotary circuit breakers, providing one normally open and one normally closed auxiliary contact for status signaling and control feedback. It is installed on the side of motor protectors in control panels, where it converts breaker operating states into electrical signals for relays or control circuits. During operation, it enables remote monitoring of trip conditions in HVAC systems, supporting system interlocking, secure logic, and automated control operations.