Why Choose the Lovato RFN420250 Thermal Overload Relay?
The Lovato RFN420250 is a heavy-duty thermal motor protection relay designed to protect three-phase motors against sustained overload conditions in demanding industrial applications. As part of the Lovato RFN420 motor protection relay series, it provides an adjustable high-current protection range and is specifically designed for applications where phase failure or single-phase sensitivity is not required.
The RFN420250 provides selectable manual or automatic resetting, allowing the reset method to be configured according to the requirements of the motor control system. Its Class 10A tripping characteristic, integrated test button and trip indicator support dependable protection and straightforward maintenance, while integrated normally open and normally closed auxiliary contacts allow connection to control and signalling circuits.
With an adjustable operational current range of 150–250 A and a rated operational voltage of 690 V, the RFN420250 is designed for high-current three-phase motor applications. Its screw-mounted construction, IP20 frontal protection and robust power terminals make it suitable for industrial switchgear, motor control panels and machinery installations.
Key Advantages
- Heavy-duty thermal overload protection for three-phase motors.
- 150–250 A adjustable operational current range for high-current motor applications.
- Selectable manual or automatic reset to suit different control requirements.
- Class 10A tripping characteristic for defined motor overload protection.
- Integrated test button and trip indicator simplify testing and fault identification.
- Integrated 1 NO + 1 NC auxiliary contacts for control and signalling circuits.
Key Features
- Lovato RFN420 motor protection relay series.
- 150–250 A adjustable operational current range.
- Three-pole thermal release.
- 690 V rated operational voltage.
- 1000 V rated insulation voltage.
- Selectable manual or automatic reset mode.
- Class 10A tripping characteristic.
- Non-phase-failure and non-single-phase-sensitive operation.
- Integrated test button and trip indicator.
- 1 NO + 1 NC auxiliary contacts.
Reliable Motor Protection for Industrial Machinery
Thermal overload relays such as the Lovato RFN420250 protect electric motors by responding to sustained overcurrent conditions that can cause excessive heating and equipment damage. Its adjustable 150–250 A operating range allows the protection setting to be matched to the motor's full-load current, while the Class 10A tripping characteristic provides a defined thermal overload response.
The RFN420250 is designed for high-current motor circuits where phase failure sensitivity is not required. Its selectable manual or automatic reset, test button, trip indicator and auxiliary contacts provide flexible integration into industrial control systems, making it suitable for demanding motor control, machinery and switchgear applications.
Typical Applications
- High-current three-phase motor overload protection.
- Industrial motor control panels and switchgear.
- Large pumps, fans and ventilation equipment.
- Compressors and processing machinery.
- Conveyors and material handling systems.
- Heavy industrial machinery and automation systems.
