The Siemens 3RT1956-1CC00 is a SIRIUS-series surge suppressor built as an RC element — a resistor-capacitor snubber — designed to clamp voltage transients across the coil of a 3RT1 contactor in sizes S6, S10, and S12 with screw terminals on the drive side. It handles control supply voltages of 48…127 V AC at either 50 or 60 Hz, and 70…150 V DC, accepting both AC and DC control circuits without a separate coil-voltage variant.
The 70…150 V DC range covers the most common 110 V DC and 125 V DC control buses found in power-generation and heavy-industrial panels; the 48…127 V AC window matches standard 110 V and 120 V control transformers as well as 48 V AC pilot circuits. Because it is an RC element rather than a varistor or diode, it suppresses both the turn-off inductive kick and the turn-on inrush spike — the resistor limits the capacitor discharge current, which keeps the contactor's auxiliary contacts from welding on high-inductance loads like large DC coils.
The part carries a RoHS substance prohibition date of July 1, 2006, confirming compliance with the EU RoHS directive since its original market introduction.