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RF420420 – T/O RELAY RF420 250-420A
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.
£395.32
Why Choose the Lovato RF420420 Motor Protection Relay?
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.
Key Advantages
- 250–420 A adjustable operational current range for high-current motor protection.
- Three-pole thermal overload relay for three-phase motor applications.
- Phase-failure and single-phase sensitive design for enhanced motor protection.
- Selectable manual or automatic reset for flexible operation.
- Class 10A tripping characteristic for motor overload protection.
- 1 NO + 1 NC auxiliary contacts for integration with control and signalling circuits.
Key Features
- Lovato RF420 motor protection relay series.
- 250–420 A operational current range.
- 690 V rated operational voltage.
- 1000 V rated insulation voltage Ui.
- 6 kV rated impulse withstand voltage Uimp.
- 50–60 Hz operational frequency.
- Class 10A thermal overload protection.
- IP20 frontal protection rating.
- Integrated test button and trip indicator.
- Manual or automatic resetting.
Reliable Thermal Overload Protection for Industrial Motors
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.
Typical Applications
- High-current three-phase industrial motor protection.
- Motor starters and motor control centres.
- Heavy industrial machinery and production equipment.
- Pumps, fans and material handling systems.
- Electrical control panels and switchgear.
- Industrial automation and process equipment.
Technical Specifications
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| Current Range | 250–420 A | |
|---|---|---|
| Device Type | Thermal Overload Relay | |
| Load Voltage | 690 V | |
| Monitored Supply | Single-phase | |
| Reset Type | Manual or automatic | |
| Monitoring Function | Temperature / thermistor | |
| Contacts | 1NO + 1NC | |
| 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 |
Frequently Asked Questions
What is the Lovato RF420420 used for?
The RF420420 is a three-pole thermal overload motor protection relay designed to protect three-phase motors against overload and phase failure conditions.
What is the current range of the Lovato RF420420?
The RF420420 has an adjustable operational current range of 250–420 A.
What tripping class does the RF420420 use?
The Lovato RF420420 has a Class 10A tripping characteristic.
Can the Lovato RF420420 be reset automatically?
Yes. The RF420420 supports both manual and automatic resetting.
Does the RF420420 provide phase failure detection?
Yes. The RF420420 is phase-failure and single-phase sensitive for additional motor protection.
Trusted Motor Protection from Lovato Electric
The Lovato RF420420 combines high-current thermal overload protection, phase-failure sensitivity and flexible resetting for dependable motor protection in demanding industrial control applications.
