Reversing contactor assembly for motor direction control
The 3RA2345-8XB30-1AL2 is a Siemens SIRIUS reversing contactor assembly — two mechanically interlocked contactors in one package for forward/reverse motor control without external interlocks. At 480 V it carries 77 A continuous; at 600 V it carries 62 A — the current derates as voltage rises due to the contactor's thermal and arc extinction limits.
Mounting and mechanical integration
The enclosure measures 160 mm high by 150 mm wide by 152 mm deep — a compact S3 footprint that fits alongside other SIRIUS components in a grouped motor control centre. Mounting position is flexible: the assembly can be rotated ±180° on a vertical surface and tilted forward or backward by ±22.5°, which helps when routing cables in a crowded panel.
Duty cycle and mechanical endurance
Rated for 10 million mechanical operations typical — this is the expected life before contact wear becomes significant under normal switching conditions. Maximum switching frequency in AC-3 duty is 1,000 operating cycles per hour, meaning the contactor can reverse a motor every 3.6 seconds without exceeding its thermal recovery time. Each direction of rotation uses one supplied contactor — the assembly ships with two 3RT2045-1AL20 contactors, pre-interlocked for reversing service.
Termination and wiring
Both the main current circuit and the magnet coil use screw-type terminals — no spring-cage tooling required, just a Pozidriv screwdriver for termination.