Siemens SIRIUS 3RT1926-1TR00 Surge Suppressor — 24 V DC Diode Assembly
The Siemens SIRIUS 3RT1926-1TR00 is a surge suppressor with diode assemblies, designed for 24 V DC control supply voltage circuits. It plugs into the bottom of a size S0 contactor or similar SIRIUS device, suppressing inductive kickback from the coil when the DC circuit opens — protecting downstream PLC outputs and auxiliary contacts from voltage spikes that exceed their rated blocking voltage.
The suppressor plugs into the bottom of a size S0 contactor — no wiring required beyond the contactor coil terminals. Verify the contactor coil voltage matches 24 V DC; the diode assembly is polarity-sensitive, so the DC supply polarity must be consistent with the module's internal diode orientation.