Siemens 3SB3400-1L Pushbutton Modular Contact Block

Siemens 3SB3400-1L is a modular contact block accessory for the 3SB3 pushbutton units in the SIRIUS signaling and control family. It provides a single contact element to extend the functionality of a 3SB3 module, enabling an auxiliary contact within a compact, modular pushbutton assembly. The 3SB3400 series encompasses variants labeled 1F, 1G, 1L, and 1H, all described by Siemens documentation as contact blocks with one contact, designed to accompany 3SB3 pushbuttons and indicator lights for simple interlocking, feedback, or signaling in control circuits. Common applications include industrial automation panels where an auxiliary contact is needed alongside the main pushbutton or indicator device. This accessory is documented in official Siemens literature as a one-contact auxiliary block compatible with the 3SB3 modular system.