Reversing contactor build — what the description tells a panel builder
The 3RA9012-5AU21: This is a 3-pole reversing contactor assembly with 2NO-2NC auxiliary contacts per contactor, a built-in coil suppressor, and a 24 VDC coil rated at 40 A. The reversing pair means two contactors mechanically interlocked — one for forward, one for reverse — so both cannot close simultaneously. The 2NO-2NC aux contacts per coil give four spare signal poles for status feedback or interlocking in the control circuit. The coil suppressor is integrated, so no external flyback diode or RC snubber is needed across the 24 VDC coil — saves a DIN-rail component and a wiring step.
Lifecycle status — active production, no replacement needed
For contract manufacturing, this sits on the customer's AVL as a Siemens-specified reversing contactor — no deviation needed unless the AML explicitly lists an alternate.
No stock-holding claim — each order is quoted per the customer's requested volume and delivery window.