The Siemens SIRIUS 3RT1926-1BB00 is a varistor-type surge suppressor designed to clip onto the coil terminals of SIRIUS contactors in sizes S0, S2, and S3. It protects the coil circuit from voltage spikes during switching — the varistor clamps the transient, not just snubs it with an RC network. Rated for both AC and DC control supplies: 24 to 48 V AC at 50/60 Hz, and 24 to 70 V DC.
Mounting and fit
Clip-on fastening method — snaps directly onto the contactor coil terminals without tools. Mounts in any position, which helps when you're squeezing it into a tight panel alongside other SIRIUS gear. Fits S0, S2, and S3 contactor sizes, so it covers the mid-to-large frame range in the SIRIUS family.
Environmental tolerance
The 60 °C operating ceiling aligns with the contactor's own rating, so you don't lose headroom on the coil protection in a hot cabinet.
The manufacturer lists this as a current-production item. The official successor is the SIRIUS 3RT2 series, but the 3RT1926-1BB00 remains available through independent distribution.