Siemens 3RT20171AF01 Contactors
Key specifications: 3RT20171AF01
| Parameter | Value |
|---|---|
| Base Product Number | 3RT2017 |
| Contact Form | 3PST-NO (3 Form A) |
| Contact Rating | 12 A |
| Coil Voltage | 110VAC |
| Coil Power | 37VA |
| Must Operate Voltage | 93.5 VAC |
| Mounting Type | Chassis Mount, DIN Rail |
| Operate Time | 33 ms |
| Operating Temperature | 25°C ~ 60°C |
| Features | Auxiliary Contacts |
| Encapsulation | Bulk |
Trade-off assessment: 3RT20171AF01
-
Coil in-rush vs. holding power — 37VA draw at closure is roughly 8× the sealing value; voltage dip on adjacent loads during pull-in requires checking supply impedance and upstream protective device coordination.
-
Must-operate threshold at 93.5 VAC — nominal supply must stay above 85 % of rated coil voltage during closing; undervolt conditions or heavy starting currents on the same feeder can cause dropout.
-
S00 frame current limit — 12 A rating constrains direct switching to motor loads or heating loads within that envelope; branch protection must be coordinated to the contactor's thermal curve.
-
Fixed 1NO auxiliary — auxiliary contact is factory-wired and cannot be reconfigured in the field; specify the NC version (3RT20171AF02) if fail-safe status signaling is needed.
-
Operating temperature ceiling 60°C — enclosed panel ambient in high-density cubicles may exceed this rating; thermal imaging or forced-air assessment is warranted.
Comparison vs. voltage variants
The reader must verify each alternate independently. The seed 3RT20171AF01 (110VAC coil) shares its 12A rating, S00 frame, DIN rail mounting, and 3-form-A main contact arrangement with the following in-catalog variants:
| MPN | Coil Voltage | Must Operate | Coil Power | Contact Config | Similarity |
|---|---|---|---|---|---|
| 3RT20171AF01 | 110VAC | 93.5 VAC | 37VA | 1NO | — |
| 3RT20171AF02 | 110VAC | 93.5 VAC | 33VA | 1NC | 1.0 |
| 3RT20171AP01 | 230VAC | 195.5 VAC | 37VA | 1NO | 1.0 |
| 3RT20171AU01 | 240VAC | 204 VAC | 33VA | 1NO | 1.0 |
| 3RT20171AQ01 | 380VAC | 323 VAC | 33VA | 1NO | 1.0 |
| 3RT20171AV01 | 400VAC | 340 VAC | 33VA | 1NO | 1.0 |
| 3RT20171AH01 | 48VAC | 40.8 VAC | 33VA | 1NO | 1.0 |
| 3RT20171AD01 | 42VAC | 35.7 VAC | 33VA | 1NO | 1.0 |
| 3RT20171AB01 | 24VAC | 20.4 VAC | 37VA | 1NO | 1.0 |
- 3RT20171AF02 differs only in auxiliary polarity (NC vs. NO); identical coil ratings and 33VA power draw.
- 3RT20171AP01 / AU01 use higher voltage coils (230VAC / 240VAC); must-operate thresholds scale accordingly.
- 3RT20171AB01 shares the 37VA power figure and bulk packaging with the seed, but targets 24VAC control systems.
Engineering verification checklist
- Confirm control-circuit nominal voltage and tolerance band against must-operate spec (93.5 VAC).
- Verify short-circuit protective device coordination with 12A thermal rating and contactor let-through.
- Check panel enclosure ambient against 25°C–60°C operating range; derate if necessary.
- Validate that the 1NO auxiliary polarity matches the machine's status-monitoring or interlock logic.
- Confirm supply impedance is low enough that voltage dip during coil pull-in does not exceed 10 % at the coil terminals.
- Verify DIN rail or chassis mounting orientation meets dimensional clearance requirements for adjacent devices.
- Review in-rush current impact on upstream transformer or genset sizing if the contactor switches motors.