Part Overview and Sourcing Reality
The Siemens 3RT1936-1ES00 is a SIRIUS surge suppressor with diode assemblies, designed for DC control supply voltages from 30 to 250 V. It mounts onto contactors of sizes S2 and S3 to suppress voltage spikes from the coil when de-energized, protecting downstream electronics and extending contactor life.
What the DC Voltage Range Means for Fit
The 30 to 250 V DC range covers the vast majority of industrial DC control voltages — 24 V nominal systems (which operate between roughly 20-30 V) are at the low end of the range, while 110 V and 220 V DC control buses are well within it. This is a single-range device, not auto-ranging; it must be selected for the specific control voltage present. The diode assembly design means polarity matters — verify the DC supply polarity matches the suppressor's orientation before installation.
Integration Note for Panel Builders
This suppressor is sized for SIRIUS contactors in frame sizes S2 and S3. It clips directly onto the contactor coil terminals — no separate DIN-rail mounting or additional wiring is needed beyond connecting the control wires. The diode assembly provides a defined current path during coil de-energization, which is critical for DC-operated contactors where the inductive kickback can otherwise damage PLC outputs or control relays.