SIRIUS varistor surge suppressor for size S0 contactors
The Siemens 3RT6926-1BF00 is a SIRIUS-brand varistor surge suppressor designed for size S0 motor contactors — it clamps voltage transients from inductive coil switching, protecting the contactor coil and downstream PLC outputs from overvoltage spikes.
Panel fit and clip-on mounting
The 12 mm depth, 30 mm width, and 19 mm height footprint clips directly onto the contactor — no DIN rail space needed, and it mounts in any orientation, so it fits tight panel layouts where a separate surge module would crowd the wiring trough.