Why Choose the Lovato RF380040 Thermal Overload Relay?
The Lovato RF380040 is a three-pole thermal overload relay designed to protect three-phase motors against sustained overloads and phase failure. Part of the Lovato Electric RF38 series, it mounts directly onto compatible BF09–BF38 contactors for a compact motor-control assembly.
Its adjustable 0.25–0.40 A current range enables the relay to be matched to the protected motor’s rated current. The trip class 10A thermal release provides dependable overload protection, while phase-failure sensitivity helps protect motors when one supply phase is lost.
The RF380040 supports manual or automatic resetting and includes a test button, trip indicator and 1NO + 1NC auxiliary contacts. Its front face is rated IP20, and the relay is suitable for operational frequencies from 0–400 Hz.
Key Advantages
- Adjustable 0.25–0.40 A motor protection range.
- Phase-failure and single-phase sensitivity for enhanced motor protection.
- Direct mounting onto Lovato BF09–BF38 contactors.
- Selectable manual or automatic reset operation.
- Integrated test button and visible trip indication.
- 1NO + 1NC auxiliary contacts for signalling and control circuits.
Key Features
- Lovato Electric RF38 series thermal overload relay.
- Three-pole thermal release for three-phase motors.
- 0.25–0.40 A adjustable current setting.
- Trip class 10A.
- Phase-failure and single-phase sensitive operation.
- Manual or automatic reset selection.
- Built-in test button and trip indicator.
- Direct mounting on BF09–BF38 contactors.
- Front protection rating of IP20.
Reliable Thermal Protection for Three-Phase Motors
Thermal overload relays monitor the current drawn by a motor and interrupt its contactor control circuit when a sustained overload is detected. Correctly setting the RF380040 within its 0.25–0.40 A range helps protect motor windings against excessive heating and premature failure.
The relay’s phase-failure sensitivity provides additional protection where loss of one phase could cause damaging current imbalance. As an overload relay does not provide short-circuit protection, it must be used with suitable upstream fuses or another appropriate short-circuit protective device.
Typical Applications
- Protection of low-current three-phase motors.
- Motor starters using Lovato BF09–BF38 contactors.
- Industrial pumps, fans and ventilation equipment.
- Conveyors and material-handling machinery.
- Packaging and production equipment.
- Industrial control panels and automation systems.
