The Siemens SIRIUS 3RT2926-1ES00-ZX90 is a surge suppressor with diode assemblies, designed for DC control circuits from 30 to 250 V. It clips onto S0-size contactors — the same S0 frame used across the SIRIUS contactor range — and suppresses the inductive kickback from the coil when the contactor drops out. At 12 mm deep, 30 mm wide, and 19 mm tall, it adds negligible depth to the contactor stack; the clip-on fastening means no extra wiring or DIN-rail space is consumed.
Mounts in any position directly onto the contactor's coil terminals — no additional DIN-rail footprint. The diode combination handles DC suppression across the full 30 to 250 V range, so one part number covers a wide control-voltage spread in a panel. The multi-unit packaging (ZX90 suffix) typically indicates a bulk pack for panel builders running multiple identical contactors.