Reversing contactor assembly for motor direction control
The Siemens 3RA2325-8XD34-1DW4 is a SIRIUS reversing contactor assembly in the S0 frame size, built around two 3RT2025-1DW44-3MA0 contactors that handle forward and reverse motor rotation through a mechanical interlock. This is the assembly you reach for when a conveyor, pump, or actuator needs to reverse direction under load — the interlock prevents both contactors pulling in at the same time, which would phase-to-phase short the motor terminals. The AC-3 duty rating means it switches squirrel-cage motors during starting and plugging — the contacts close on inrush and break at running current, not stalled rotor current, so the electrical life holds up through thousands of reversals.
Mounting and panel integration — DIN rail with orientation flexibility
Mounts on 35 mm standard mounting rail via screw or snap-on fastening. Clearance distances are 6 mm upwards, forwards, downwards, and to the sides; zero clearance backwards means it can sit flush against the backplane. Dimensions are 181 mm deep, 90 mm wide, 101 mm tall — the 90 mm width is the S0 frame standard, so it occupies one 90 mm slot on the DIN rail. The depth of 181 mm includes the contactor bodies and the varistor surge suppressor fitted as standard; check the enclosure depth against this figure, particularly in shallow wall-mount boxes.
Terminal capacity and wiring — screw-type for main and coil
The AWG equivalents for main contacts are 2x (16 to 12) and 2x (14 to 8). The magnet coil also uses screw terminals — no cage-clamp or push-in on this variant, so factor in screwdriver access during panel wiring. The supplied contactors (two 3RT2025-1DW44-3MA0 units) each carry three main poles per direction of rotation, giving six instantaneous contacts total. The varistor surge suppressor is built into the assembly — it clips the coil turn-off transient, which matters if the PLC output driving this contactor shares a DC common rail with sensitive analog inputs.
Environmental and compliance — temperature range, shock, RoHS
The shock resistance is specified at AC: 11.8 g for 5 ms and 7.4 g for 10 ms; DC: 15 g for 5 ms and 10 g for 10 ms. Mechanical life is 10,000,000 cycles typical — this is the contactor mechanism, not the electrical life under load, which depends on the switching duty and motor current.