The Siemens 3RT7926-1CD00 is a SIRIUS surge suppressor — an RC element designed to plug directly onto 3RT7 S0-size contactors. It snubs voltage spikes from the coil circuit, protecting nearby electronics and extending contactor life on inductive loads like motor starters or valve solenoids. Rated for AC control supplies at 127–240 V (50/60 Hz) and DC supplies at 150–250 V, it handles both common line voltages without a separate coil-voltage variant. The AC/DC input means one part covers a mixed-voltage panel — useful when a line has both 230 VAC and 200 VDC control circuits.
Mounting and fit
Clip-on fastening snaps directly onto the contactor's coil terminals — no tools, no extra wiring. The 12 mm depth and 30 mm width keep it flush with the contactor body, so it doesn't steal DIN-rail space or block adjacent devices in a dense panel. Storage tolerance down to -25 °C is fine for unheated warehouses.