What it is and where it fits
The Siemens 3RH2122-1BE40-ZX95 is a size S00 contactor relay with two instantaneous normally-open auxiliary contacts. It mounts on a 35 mm DIN rail via the screw and snap-on method, and fits in a 73 mm deep, 45 mm wide, 58 mm tall envelope — standard for the S00 frame in a control panel. The product extension for auxiliary switches is supported, so you can add more contacts on the same rail footprint without reworking the panel layout.
Switching capability and ratings
The contacts are rated for DC switching across a range of voltages: 10 A at 24 V, 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, and 0.26 A at 600 V. For AC loads, the relay handles 10 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. These numbers define the contactor's interrupting capacity at each voltage — useful for sizing on motor control or resistive circuits. The arcing time is 10 to 15 ms, and the closing and holding power of the magnet coil is 4 W DC. The operating frequency at DC-12 duty is up to 1,000 operations per hour.
Mounting and environment
Mounts on a 35 mm DIN rail with screw and snap-on fastening. The mounting position allows +/- 180° rotation on a vertical surface, and can be tilted forward and backward by +/- 22.5°. Clearance around the unit: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the side. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C. Pollution degree 3, rated surge voltage resistance 6 kV. The substance prohibition date for RoHS-like compliance is October 1, 2009.