32 A reversing contactor, 24 VDC coil — what it does in a panel
The 3RA9012-5AS18 is a Siemens reversing contactor, 3-pole, rated 32 A, with a 24 VDC coil. It includes 1NO-3NC auxiliary contacts per contactor, and the 'integral S' designation means the overload relay and contactor are factory-matched as a single assembly — no loose parts to wire up, no mis-match on the rail. This is a Motor Starters category part, so it's built for starting and reversing three-phase motors in control panels. The reversing configuration swaps two phases to reverse the motor direction — typical for conveyors, hoists, or any line that needs forward/reverse without a separate interlock relay.
Lifecycle and sourcing — active, quoted to order
No stock-holding claim — quoted per RFQ.
What the 32 A rating means for motor duty
32 A is the continuous thermal current (Ith) for a reversing contactor in this frame size — it's the current the main poles can carry without exceeding the temperature rise limit. For AC-3 motor switching (starting and stopping a squirrel-cage motor under load), a 32 A contactor typically handles a 15–18 kW motor at 400 V, but the exact motor FLC must be checked against the contactor's AC-3 rating in the Siemens selection table. The 24 VDC coil draws a holding current in the tens of milliamps once picked — the inrush is higher but brief. The 1NO-3NC aux contacts per contactor give you one normally-open and three normally-closed auxiliary poles for status feedback or interlocking, which is useful for reversing circuits where mechanical interlocks aren't enough.