Siemens SIRIUS 3RH21 coupling contactor relays are 24 V DC contactor relays with low coil power for direct control from solid-state PLC outputs. Versions without surge suppression, with integrated diode or suppressor diode, and with operating range 0.7–1.25 × Uc (2.8 W) or 0.85–1.85 × Uc (1.6 W) are available. They cannot be expanded with auxiliary switches.
Technical data
| Size | S00 |
|---|---|
| Mounting | Screw or snap-on mounting on TH35 DIN rail |
| Connection | Screw (box) or spring-loaded terminals, depending on article number |
| Standards | IEC 60947-1, IEC 60947-4-1, IEC 60947-5-1 |
| Contacts | 4 |
| Rated operational current Ie/AC-15 at 230 V | 10 A |
| Coil | 24 V DC |
| Coil power (24 V) | 2.8 W or 1.6 W (depending on version) |
| Suitable for | Direct control from solid-state PLC outputs |
| Note | Cannot be expanded with auxiliary switches |
Article numbers
| Contacts | Coil circuit | Operating range | Coil power | Screw terminals | Spring-loaded terminals |
|---|---|---|---|---|---|
| 4 NO | No surge suppression | 0.7–1.25 × Uc | 2.8 W | 3RH2140-1HB40 | 3RH2140-2HB40 |
| 3 NO + 1 NC | No surge suppression | 0.7–1.25 × Uc | 2.8 W | 3RH2131-1HB40 | 3RH2131-2HB40 |
| 2 NO + 2 NC | No surge suppression | 0.7–1.25 × Uc | 2.8 W | 3RH2122-1HB40 | 3RH2122-2HB40 |
| 4 NO | No surge suppression | 0.85–1.85 × Uc | 1.6 W | 3RH2140-1MB40-0KT0 | 3RH2140-2MB40-0KT0 |
| 3 NO + 1 NC | No surge suppression | 0.85–1.85 × Uc | 1.6 W | 3RH2131-1MB40-0KT0 | 3RH2131-2MB40-0KT0 |
| 2 NO + 2 NC | No surge suppression | 0.85–1.85 × Uc | 1.6 W | 3RH2122-1MB40-0KT0 | 3RH2122-2MB40-0KT0 |
| 4 NO | Integrated diode | 0.7–1.25 × Uc | 2.8 W | 3RH2140-1JB40 | 3RH2140-2JB40 |
| 3 NO + 1 NC | Integrated diode | 0.7–1.25 × Uc | 2.8 W | 3RH2131-1JB40 | 3RH2131-2JB40 |
| 2 NO + 2 NC | Integrated diode | 0.7–1.25 × Uc | 2.8 W | 3RH2122-1JB40 | 3RH2122-2JB40 |
| 4 NO | Integrated diode | 0.85–1.85 × Uc | 1.6 W | 3RH2140-1VB40 | 3RH2140-2VB40 |
| 3 NO + 1 NC | Integrated diode | 0.85–1.85 × Uc | 1.6 W | 3RH2131-1VB40 | 3RH2131-2VB40 |
| 2 NO + 2 NC | Integrated diode | 0.85–1.85 × Uc | 1.6 W | 3RH2122-1VB40 | 3RH2122-2VB40 |
| 4 NO | Integrated suppressor diode | 0.7–1.25 × Uc | 2.8 W | 3RH2140-1KB40 | 3RH2140-2KB40 |
| 3 NO + 1 NC | Integrated suppressor diode | 0.7–1.25 × Uc | 2.8 W | 3RH2131-1KB40 | 3RH2131-2KB40 |
| 2 NO + 2 NC | Integrated suppressor diode | 0.7–1.25 × Uc | 2.8 W | 3RH2122-1KB40 | 3RH2122-2KB40 |
| 4 NO | Integrated suppressor diode | 0.85–1.85 × Uc | 1.6 W | 3RH2140-1SB40 | 3RH2140-2SB40 |
| 3 NO + 1 NC | Integrated suppressor diode | 0.85–1.85 × Uc | 1.6 W | 3RH2131-1SB40 | 3RH2131-2SB40 |
| 2 NO + 2 NC | Integrated suppressor diode | 0.85–1.85 × Uc | 1.6 W | 3RH2122-1SB40 | 3RH2122-2SB40 |
Technical data and article numbers are based on Siemens catalog IC 10 · 2026 (chapter 5, SIRIUS 3RH2 contactor relays) and are for information only. Image is representative. Coil voltages not listed in the table are available on request according to the Siemens catalog.
For price, stock and lead time, use the Request a Quote button or call +90 533 945 27 94. Sending the article number from the table is enough.
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