What this reversing contactor assembly is
The Siemens 3RA2316-8XB34-1DW4 is a SIRIUS reversing contactor assembly — a pre-configured pair of contactors mechanically and electrically interlocked to reverse a three-phase motor without external wiring. It ships with two 3RT2016-1DW44 contactors already mounted and wired on a common base plate, saving panel build time over sourcing and assembling the pair separately. Current ratings are 7.6 A at 480 V and 9 A at 600 V.
Mounting is flexible: screw-fix or snap onto a 35 mm standard DIN rail. Clearance distances are 6 mm upwards, forwards, downwards, and to the side, with 0 mm backwards — so the back of the unit can sit flush against the panel or backplane. At 90 mm wide, 68 mm tall, and 145 mm deep, it fits standard S00 contactor footprint spacing.
Terminal wiring and surge protection
Both the magnet coil and main current circuit use screw-type terminals. A built-in varistor surge suppressor is fitted across the coil, which saves adding a separate suppression module and reduces the chance of coil-driver damage from inductive kickback during switching.
Environmental and mechanical life
Shock resistance is rated at 10.5g for 5 ms and 6.6g for 10 ms on both AC and DC axes, covering typical vibration in motor control centres. Mechanical life of the contactor is rated at 10,000,000 operations typical — this is the contactor pair's endurance under no-load cycling, not the electrical life under load (which is lower and depends on switching frequency and motor current).