The Siemens 3RT1944-5AK62 is a SIRIUS magnet coil for Size S3 contactors with spring-loaded connection technology. It operates on 110 V AC at 50 Hz or 120 V AC at 60 Hz, with a rated control supply voltage type of AC.
Lifecycle and Sourcing
This part is flagged as a phased-out product. The official successor is the SIRIUS 3RT2 series. For a BOM freeze or last-time-buy planning, the 3RT2 family is the drop-in replacement path. Sourced to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.
What the Ratings Mean for Fit
The coil draws 0.8 to 1.1 A at 50 Hz — that's the inrush current at pickup, not the holding current. The holding VA is lower, but the pick-up surge is what stresses the control transformer. If you're replacing a coil in an existing SIRIUS Size S3 contactor, the spring-loaded terminals accept the same wire range as the original screw terminals, so no re-termination needed. The 110 V AC / 120 V AC dual-frequency rating means it works on 50 Hz or 60 Hz supply without a separate tap change.
Comparison to the 3RT1017-1AK61
The 3RT1017-1AK61 is a complete power contactor (Size S00), not just a coil. It uses screw terminals and has a different mounting footprint (45 mm wide, 57.5 mm tall) versus the Size S3 coil's spring-loaded connection. The 3RT1944-5AK62 coil will not drop into a panel wired for the 3RT1017-1AK61 without changing the contactor base and rewiring the control circuit.