The Siemens SIRIUS 3RT1924-5AD21 is a replacement magnet coil for Size S0 contactors in the SIRIUS family. The coil operating range at 50 Hz is listed as 0.8... 1.1, which tells you the voltage tolerance band the coil will reliably pick up and hold at.
Siemens 3RT1924-5AD21 SIRIUS Magnet Coil, 42 V AC, Size S0
MPN3RT1924-5AD21
Siemens SIRIUS 3RT1924-5AD21 magnet coil, Size S0, screw terminal, 42 V AC 50/60 Hz, for SIRIUS contactors.
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Independent China distributor & sourcing agent· Listing updated Sep 2026
Specifications
| Parameter | Value |
|---|---|
| Control supply voltage type | AC |
| Rated value @ 50 Hz | 0.8 ... 1.1 |
| Rated value @ 50 Hz | 42 V |
| Parameter | Value |
|---|---|
| At 60 Hz rated value | 42 V |
Product details
Frequently asked questions
What replaces the 3RT1924-5AD21?
The official Siemens preferred successor is the 3RT2924-5AD21. Same Size S0 form factor, same 42 V AC coil voltage, same screw-terminal connection. It should be a direct mechanical and electrical swap.
Will the 3RT1924-5AD21 fit a panel built around the 3RT7045-1AH20?
No. The 3RT7045-1AH20 is a Size S3 contactor. The 3RT1924-5AD21 is a Size S0 coil. The mounting footprint, terminal spacing, and mechanical interface are different. Stick with the Size S0 coil family for S0 contactors.
MPN
3RT1924-5AD21