Siemens 3RT20281AG20 Contactors
Compare: 3RT20281AG20 vs S0 Family Variants
All parts share: 38 A rating, 3PST-NO contact form, chassis/DIN rail mounting, 79–81 VA coil power, 40 ms operate time, auxiliary contacts. Operating temperature and encapsulation vary.
| Spec | 3RT20281AG20 (seed) | 3RT20281AG24 | 3RT20281AL20 | 3RT20281AN20 | Similarity |
|---|---|---|---|---|---|
| Coil Voltage | 110 VAC | 110 VAC | 230 VAC | 220 VAC | — |
| Operating Temp | 25°C ~ 60°C | 25°C ~ 60°C | 25°C ~ 60°C | 25°C ~ 60°C | — |
| Encapsulation | Box | Box | Bulk | Bulk | — |
| Must Operate Voltage | 93.5 VAC | 93.5 VAC | 195.5 VAC | 187 VAC | — |
3RT20281AG24 — same 110 VAC coil; adds a second NO contact pair (2NO/2NC vs 1NO/1NC). Shared 93.5 VAC dropout threshold and box packaging.
3RT20281AL20 — 230 VAC coil for higher-voltage control systems; 81 VA inrush; bulk packaging. Must-operate rises to 195.5 VAC per 0.85× specification.
3RT20281AN20 — 220 VAC coil; 81 VA inrush; bulk packaging. Must-operate at 187 VAC; useful where 230 V supply sag is a concern.
3RT20281AG20 Specifications
| Parameter | Value |
|---|---|
| Coil Voltage | 110 VAC |
| Coil Power (inrush) | 79 VA |
| Contact Rating | 38 A |
| Contact Form | 3PST-NO (3 Form A) |
| Auxiliary Contacts | 1 NO / 1 NC |
| Mounting | Chassis Mount, DIN Rail |
| Must Operate Voltage | 93.5 VAC |
| Operate Time | 40 ms |
| Operating Temperature | 25°C ~ 60°C |
| Encapsulation | Box |
| Base Product Number | 3RT2028 |
The S0 frame accommodates motor loads up to 38 A AC-3. The 93.5 VAC must-operate spec defines pickup under nominal 110 V supply (±10% tolerance implied). Operating range extends to 60°C ambient, suitable for enclosed MCC buckets without supplemental cooling in most indoor installations.
Engineering verification checklist
- Confirm control-circuit voltage matches 110 VAC nominal; verify sag tolerance against 93.5 VAC must-operate threshold
- Verify auxiliary contact logic (1NO/1NC) suits the interlock or signal requirement in the circuit
- Check panel enclosure temperature profile; operating limit is 60°C ambient
- Validate DIN rail clip engagement for the target enclosure rail profile
- Confirm 38 A AC-3 rating covers full-load current of the connected motor branch
- Verify must-operate voltage against any upstream transformer tap or long control runs
- Compare enclosure packaging (box vs bulk) for any derating or environmental exposure differences