The Siemens 3RT6926-1ER00 is a SIRIUS surge suppressor built as a diode combination, sized for S0 contactor frames. It clips onto the contactor coil terminals and suppresses the inductive kickback when a DC coil de-energizes — protecting the PLC output or relay that drives it. Rated for 24 V DC control supply voltage, it matches the standard 24 VDC control voltage found across most modern panels.
The suppressor clips onto the contactor (clip-on fastening method) and occupies no extra DIN-rail space — it sits on the coil terminals. Dimensions are 12 mm deep, 30 mm wide, 19 mm high, so it stays within the S0 contactor envelope. Mounting position is any, which helps when the contactor is installed sideways or upside-down in a tight enclosure.
Environmental range
No derating needed for the suppressor itself — the contactor's coil dissipation is the thermal limit to watch.