The Siemens 3RT2916-1LN00 is a SIRIUS surge suppressor — a suppression diode with a built-in LED, sized for the S00 contactor frame. It's designed to clip onto 3RT2.1 power contactors and 3RH2 auxiliary contactors, knocking down the inductive kick from the DC coil when it de-energizes. That LED gives you a quick visual on whether the coil circuit is live, which saves a meter pull on a crowded panel.
Voltage range and what it means on the line
Rated for 70 to 150 V DC, this diode handles the common control voltages you see across European and North American DC coil circuits — 110 VDC, 125 VDC, nominal 120 VDC. The LED lights across that whole band, so you're not guessing whether the suppression is active. Below 70 V the diode won't break over cleanly; above 150 V you risk avalanche failure. Keep the coil voltage inside that window.
Clip-on fastening method, no screws, no DIN-rail footprint of its own — it snaps directly onto the contactor's coil terminals. That means zero added panel width. The suppressor itself measures 28 mm wide by 46 mm tall by just 9 mm deep, so it sits flush against the contactor face.
Environmental limits for the route
No IP rating is listed on this component; it relies on the contactor's enclosure for protection against dust and moisture.