Lovato RF380040 is a three-pole 0.25–0.40 A trip class 10A thermal overload relay with phase-failure sensitivity for direct mounting on BF09–BF38 contactors.
£66.60
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.
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.
| HS Code | 85364900 |
|---|---|
| Manufacturer | Lovato Electric |
| Series | RF38 |
| Model | RF380040 |
| Product type | Thermal overload relay |
| Number of poles | 3 |
| Current adjustment range | 0.25–0.40 A |
| Trip class | 10A |
| Phase-failure sensitivity | Yes |
| Reset type | Manual or automatic |
| Auxiliary contacts | 1NO + 1NC |
| Auxiliary contact conventional thermal current | 10 A |
| Auxiliary contact designation | B600-R300 |
| Rated operational voltage | 690 V |
| Rated insulation voltage | 690 V |
| Rated impulse withstand voltage | 6 kV |
| Operational frequency | 0–400 Hz |
| Protection rating | IP20 frontal |
| Mounting type | Direct mounting on BF09–BF38 contactors |
| Overvoltage category | III |
| Pollution degree | 3 |
| Operating temperature | -25 to +60 °C |
| Storage temperature | -50 to +70 °C |
| Temperature compensation range | -20 to +60 °C |
| Maximum operating altitude | 3000 m |
| Weight | 158 g |
The RF380040 protects three-phase motors against sustained overloads and phase failure when installed with a compatible Lovato BF09–BF38 contactor.
The relay has an adjustable current setting range of 0.25–0.40 A.
The RF380040 is designed for direct mounting on Lovato BF09–BF38 contactors.
Yes. The relay can be configured for either manual or automatic resetting.
No. It provides thermal overload and phase-failure protection, so suitable upstream short-circuit protection must also be installed.
Lovato Electric RF38 thermal overload relays provide dependable motor protection, convenient contactor mounting and practical control features for industrial motor starters and automation panels.
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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...