Standard delivery
£8 ex VAT · free over £200UK parcel delivery is £8 ex VAT, or free on orders over £200 ex VAT.
Heavier items may be charged at a weight-based or pallet rate, shown at checkout.
RF420250 – T/O RELAY RF420 150-250A
Lovato RF420250 is a three-pole Class 10A thermal overload motor protection relay with a 150-250 A operational current range and manual or automatic resetting.
£374.53
Why Choose the Lovato RF420250 Motor Protection Relay?
The Lovato RF420250 is a high-capacity three-pole thermal overload motor protection relay designed to protect industrial three-phase motors against overload conditions. Part of the Lovato RF420 motor protection relay series, it provides an adjustable operational current range of 150–250 A for demanding motor control applications.
The RF420250 features a Class 10A thermal release, manual or automatic resetting, integrated test button and trip indicator. Designed for high-current motor protection systems, it supports reliable operation and straightforward maintenance in industrial electrical installations.
With a rated operational voltage of 690 V, rated insulation voltage of 1000 V and IP20 frontal protection, the RF420250 is suitable for large motor starters and industrial control panels. Its screw fixing arrangement and auxiliary contacts provide flexible installation and control integration.
Key Advantages
- 150–250 A adjustable operational current range for high-current motor protection.
- Three-pole thermal overload relay for three-phase motor applications.
- Class 10A tripping characteristic for reliable motor overload protection.
- Selectable manual or automatic reset for flexible operation.
- Integrated test button and trip indicator simplify commissioning and maintenance.
- 1NO + 1NC auxiliary contacts for control and signalling circuits.
Key Features
- Lovato RF420 motor protection relay series.
- 150–250 A operational current range.
- 690 V rated operational voltage.
- 1000 V rated insulation voltage Ui.
- 6 kV rated impulse withstand voltage Uimp.
- Class 10A thermal overload protection.
- IP20 frontal protection rating.
- Manual or automatic resetting.
- Integrated test button and trip indication.
- 1NO + 1NC auxiliary contacts.
Reliable Thermal Overload Protection for Industrial Motors
Thermal overload relays protect motors by monitoring current levels and responding when sustained overload conditions occur. The Lovato RF420250 provides adjustable high-current protection for large three-phase motors used in industrial equipment and electrical installations.
With manual or automatic resetting, integrated testing facilities and auxiliary contacts, the RF420250 supports dependable motor starter operation while simplifying maintenance and fault identification.
Typical Applications
- Large three-phase industrial motor protection.
- Motor starters and motor control centres.
- Industrial machinery and production equipment.
- Pumps, fans and heavy-duty drive systems.
- Electrical control panels and switchgear.
- Industrial automation and process equipment.
Technical Specifications
Tick the specs you need, then view products that match.
| Current Range | 150–250 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 | RF420250 | |
| Product type | Thermal overload motor protection relay | |
| Number of poles | 3 | |
| Release type | Thermal | |
| Operational current | 150–250 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 | No | |
| Reset mode | Manual or automatic | |
| Test button | Yes | |
| Trip indicator | Yes | |
| Auxiliary contacts | 1 NO + 1 NC | |
| Frontal protection rating | IP20 | |
| Fixing type | Screw fixing | |
| Power terminal type | Screw and flat washer | |
| Power terminal size | M10 | |
| Auxiliary terminal size | M3.5 | |
| Operating temperature | -25–60 °C | |
| Storage temperature | -50–70 °C | |
| Maximum altitude | 3000 m | |
| Weight | 2460 g |
Frequently Asked Questions
What is the Lovato RF420250 used for?
The RF420250 is a three-pole thermal overload motor protection relay designed to protect high-current three-phase motors against overload conditions.
What is the current range of the Lovato RF420250?
The RF420250 has an adjustable operational current range of 150–250 A.
What tripping class does the RF420250 use?
The Lovato RF420250 has a Class 10A tripping characteristic.
Can the Lovato RF420250 be reset automatically?
Yes. The RF420250 supports both manual and automatic resetting.
Does the RF420250 include auxiliary contacts?
Yes. The relay includes 1 NO and 1 NC auxiliary contacts for control and signalling applications.
Trusted Motor Protection from Lovato Electric
The Lovato RF420250 provides high-current thermal overload protection, flexible resetting and integrated control features for reliable motor protection in demanding industrial applications.
