The Siemens 3RT6916-1DG00 is a SIRIUS surge suppressor — a suppression diode designed for DC-operated S00-size contactors and contactor relays. It clips directly onto the coil terminals of the contactor, occupying only 9 mm of DIN-rail depth. Rated for 12 to 250 V DC control supply voltage, this diode suppresses the inductive voltage spike that occurs when the DC coil is de-energized, protecting nearby PLC outputs, auxiliary contacts, and bus couplers from back-EMF damage.
The 9 mm depth and 28 mm width make this one of the slimmest surge suppressors in the SIRIUS S00 accessory line — it adds negligible panel depth beyond the contactor itself. Clip-on fastening means no wiring between the suppressor and the coil: it snaps onto the contactor's coil terminals, reducing installation time and eliminating a potential loose-connection point.
Compliance
Substance prohibitance date of 05/01/2012 indicates RoHS compliance per the EU directive effective from that date. The part carries the SIRIUS brand designation and is designed for the European and global industrial panel market.