Siemens 3RT20281BP40 S0 Contactor
Primary Specifications — 3RT20281BP40
| Parameter | Value |
|---|---|
| Coil Voltage | 230 VDC |
| Must Operate Voltage | 184 VDC |
| Coil Power | 5.9 W |
| Contact Rating (Current) | 38 A |
| Contact Form | 3PST-NO (3 Form A) |
| Mounting | Chassis Mount, DIN Rail |
| Operate Time | 170 ms |
| Operating Temperature | 25°C ~ 60°C |
| Encapsulation | Box |
| Features | Auxiliary Contacts (1NO/1NC) |
This is a size S0, 3-pole contactor from Siemens' 3RT2 series. The 230 VDC coil requires approximately 80% of nominal voltage to pull in (184 VDC must-operate threshold). The integrated 1NO/1NC auxiliary block provides auxiliary signaling without changing the main device footprint. Chassis or standard 35 mm DIN rail mounting is supported.
S0 38 A Coil Voltage Comparison
All parts below share the same 38 A contact rating, 5.9 W coil power, and DIN/chassis mounting. Coil voltage is the differentiating parameter; must-operate voltage scales proportionally.
| MPN | Coil Voltage | Must Operate | Encapsulation | Operate Time |
|---|---|---|---|---|
| 3RT20281BP40 | 230 VDC | 184 VDC | Box | 170 ms |
| 3RT20281BM40 | 220 VDC | 176 VDC | Box | 170 ms |
| 3RT20281BF40 | 110 VDC | 88 VDC | Box | 170 ms |
| 3RT20281BG40 | 125 VDC | 100 VDC | Box | 170 ms |
| 3RT20281BE40 | 60 VDC | 48 VDC | Box | 170 ms |
| 3RT20281BW40 | 48 VDC | 38.4 VDC | Box | 170 ms |
| 3RT20281BJ80 | 72 VDC | 57.6 VDC | Box | 170 ms |
| 3RT20281BB40 | 24 VDC | 19.2 VDC | Bulk | 170 ms |
| 3RT20281BF44 | 110 VDC | 88 VDC | Box | 170 ms |
Readers must verify suitability of any listed alternate for their specific control voltage and auxiliary contact configuration.
3RT20281BM40 — 220 VDC coil; 176 VDC must-operate; same box packaging; operation identical at 220 VDC vs 230 VDC.
3RT20281BF40 — 110 VDC coil; must-operate 88 VDC; offers half the control voltage for lower-power DC control architectures.
3RT20281BF44 — 110 VDC coil with 2NO/2NC auxiliary configuration instead of 1NO/1NC; use when dual auxiliary poles are required.