Siemens 3SB3400-0K Auxiliary Switch 3SB3400-0K

Siemens 3SB3400-0K is an auxiliary/alarm switch accessory designed for Siemens VL-series contactors (VL400, VL630, VL800, VL1250, VL1600). This takeout contact block provides a single normally closed (1NC) contact element with a screw-terminal connection, enabling straightforward wiring for status feedback or interlock logic. The actuator/indicator component has a 30-degree tilt, aligning with the front of the VL frame for reliable actuation when the main contactor moves. The 3SB3400-0K mounts with the VL contactor to furnish auxiliary signaling without altering the main current path; its single NC contact can be wired to drive PLC inputs, alarms, or control circuits that monitor the motor starter state. As part of the Siemens 3SB family of auxiliary and alarm switches, it offers a compact, screw-terminal interface and straightforward installation for industrial control panels. This part is cataloged as 3SB3400-0K and provides one normally closed auxiliary contact to indicate the status of the main contacts in industrial automation applications.