Lovato RF420420 is a three-pole Class 10A thermal overload motor protection relay with a 250-420 A operational current range, phase-failure sensitivity and manual or automatic resetting.
£658.87
The Lovato RF420420 is a high-capacity three-pole thermal overload motor protection relay designed to protect three-phase motors against overload and phase failure conditions. Part of the Lovato RF420 motor protection relay series, it provides an adjustable operational current range of 250–420 A for demanding industrial motor control applications.
The RF420420 is phase-failure and single-phase sensitive and provides manual or automatic resetting to suit different control requirements. Its Class 10A tripping characteristic, integrated test button and trip indicator support dependable motor protection, commissioning and fault identification.
With a rated operational voltage of 690 V, rated insulation voltage of 1000 V and an operational frequency range of 50–60 Hz, the RF420420 is engineered for high-current industrial motor protection systems. Screw fixing and integrated auxiliary contacts support installation and connection within motor control panels and starter assemblies.
Thermal overload relays help protect electric motors against damaging overload conditions by responding when sustained current exceeds the selected operating range. The Lovato RF420420 combines an adjustable 250–420 A current setting with phase-failure sensitivity and a Class 10A tripping characteristic for high-current three-phase motor protection.
Manual or automatic reset selection allows the relay to be configured for different operating requirements, while the integrated test button, trip indicator and auxiliary contacts support control circuit integration, testing and maintenance in industrial motor starter systems.
| HS Code | 85364900 |
|---|---|
| Manufacturer | Lovato Electric |
| Series | RF420 |
| Model | RF420420 |
| Product type | Thermal overload motor protection relay |
| Number of poles | 3 |
| Release type | Thermal |
| Operational current | 250–420 A |
| Rated operational voltage | 690 V |
| Rated insulation voltage Ui | 1000 V |
| Rated impulse withstand voltage Uimp | 6 kV |
| Operational frequency | 50–60 Hz |
| Tripping class | 10A |
| Phase failure detection | Yes |
| Reset mode | Manual or automatic |
| Test button | Yes |
| Trip indicator | Yes |
| Auxiliary contacts | 1 NO + 1 NC |
| Frontal protection rating | IP20 |
| Overvoltage category | III |
| Pollution degree | 3 |
| Fixing type | Screw |
| Power terminal type | Screw and flat washer |
| Power terminal screw | M10 |
| Operating temperature | -25–60 °C |
| Storage temperature | -50–70 °C |
| Maximum altitude | 3000 m |
| Quantity per package | 1 |
| Package dimensions | 150 × 152 × 178 mm |
| Package volume | 4058.4 cm³ |
| EAN | 8013975169445 |
The RF420420 is a three-pole thermal overload motor protection relay designed to protect three-phase motors against overload and phase failure conditions.
The RF420420 has an adjustable operational current range of 250–420 A.
The Lovato RF420420 has a Class 10A tripping characteristic.
Yes. The RF420420 supports both manual and automatic resetting.
Yes. The RF420420 is phase-failure and single-phase sensitive for additional motor protection.
The Lovato RF420420 combines high-current thermal overload protection, phase-failure sensitivity and flexible resetting for dependable motor protection in demanding industrial control applications.
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2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...