What this auxiliary switch does in a contactor assembly
The 3RT1926-2ED21: It provides a delayed N/O signal after the coil is energized, with the delay adjustable from 0.5 to 10 s via a potentiometer on the face of the block.
Mounting and integration with 3RT contactors
The block clips onto the front of a SIRIUS contactor using the standard accessory interface — no tools required, and it occupies the width of the contactor (33 mm). Overall dimensions are 33 mm wide, 46 mm high, and 73 mm deep, fitting within the envelope of the contactor assembly.
Wiring and contact configuration
It provides a single N/O contact with ON-delay; there is no OFF-delay, no pulse-shaping, and no star-delta circuit function.