What This Surge Suppressor Does
The Siemens 3RT2936-1BE00 is a varistor-type surge suppressor designed to clip onto SIRIUS contactors in the 3RT2.3 and 3RT2.4 size range — S2 and S3 frames. It snubs voltage transients from the AC coil circuit, protecting the PLC output or relay that drives the contactor. Rated for 240-400 V AC at both 50 Hz and 60 Hz, this suppressor covers the common European and North American control voltages in that band. The varistor clamps the spike when the coil de-energises, which is the moment a contactor's inductive kickback usually kills a solid-state output.
Mounting and Panel Fit
Clip-on fastening — no screws, no wiring between the suppressor and the contactor. It snaps directly onto the contactor's coil terminals, which saves a DIN rail slot and keeps the panel layout tight. The dimensions are 30 mm wide, 30 mm tall, and only 15 mm deep, so it adds negligible projection beyond the contactor face. Mounting position is unrestricted, and the operating temperature range is -25 to +60 °C, with storage from -40 to +80 °C. That covers most non-condensing panel environments, including cabinets near process machinery.
Lifecycle and Sourcing
RoHS compliance date is 10/01/2014, which means it meets the EU substance restrictions for equipment placed on the market after that date. No official successor or cross-reference exists — this is the direct part for the 3RT2.3 and 3RT2.4 contactor family.