The Siemens 3RT1926-1CD00 is a SIRIUS RC-element surge suppressor designed to mount directly onto Size S0 contactors. It suppresses voltage spikes across the coil when the contactor de-energizes, protecting nearby control electronics and extending contact life. The RC element handles control supply voltages of 127…240 V AC and 150…250 V DC, covering both 50 Hz and 60 Hz line frequencies.
The suppressor clips onto the coil terminals of any SIRIUS Size S0 contactor (e.g., 3RT1023 series). No additional wiring is needed — it mounts in place of the standard coil-bridge jumper. The RC element is polarity-independent for AC supplies; for DC circuits, verify the orientation matches the coil polarity to avoid defeating the suppression.