What this reversing contactor assembly does
The Siemens 3RA2316-8XB34-1CH0 is a SIRIUS reversing contactor assembly — two contactors mechanically interlocked so only one closes at a time, giving you forward/reverse control of a three-phase motor without external interlocking relays. The assembly carries 4 instantaneous auxiliary contacts total — 2 per direction of rotation — enough to latch the direction, signal the PLC, and interlock the opposite coil without adding a separate auxiliary block.
Mounting and panel fit
The 90 mm width and 130 mm depth fit a typical motor control center bucket or small panel enclosure — measure the rail space before committing, as the reversing pair takes roughly double the width of a single S00 contactor. This helps when the panel layout forces the contactor onto an angled subplate or a swing frame. Clearance around the assembly: 6 mm upwards, forwards, downwards, and to the side; 0 mm backwards (the DIN rail side). No extra breathing space needed beyond the standard 10 mm between components for heat dissipation at rated current.
Termination and wiring
Both the main power circuit and the magnet coil use screw-type terminals — no cage clamps, no push-in.
Duty ratings and motor sizing
Current ratings: 7.6 A at 480 V, 9 A at 600 V. These are AC-3 values for standard squirrel-cage motor starting. At 690 V the assembly is rated 5.5 kW, and at 500 V also 4 kW — the voltage derating is flat up to 500 V, then drops above that. Mechanical life is 10 million cycles typical — this is the contactor mechanism, not the electrical endurance under load. In reversing duty (AC-4) the electrical life will be shorter; factor that into the maintenance schedule for high-cycle applications like conveyor reversing stations.
Environmental and compliance
The assembly is rated for vibration: 10.5 g at 5 ms and 6.6 g at 10 ms on both AC and DC supplies — suitable for machine-mounted panels near rotating equipment. RoHS compliant with substance prohibition date 07/01/2006.