Generator regulator (carbon brush) - Volvo Penta 14594565 (BR28 N1) is the automatic voltage regulator of the generator: it reads the output voltage and corrects the field excitation so the voltage stays stable as the load changes.
A failing AVR shows up before it dies: voltage dips 5–30 V when a large motor starts, lights flicker, or the control panel reboots. When it fails completely the set delivers only residual voltage or trips on overvoltage.
Specifications and compatibility
This item is supplied against the equipment reference; confirm the application from the set nameplate before ordering.
How to verify before ordering
- Check that the reference printed on the AVR label (for example AS440, MX341, R120) matches exactly; variants differ in sensing range and excitation level.
- Confirm the excitation input voltage and the generator type it serves. They are not interchangeable across generator makes or speed ranges.
- Inspect wiring and brushes before replacing the module: a loose connection produces exactly the same symptoms as a burnt AVR.
Frequently asked questions
How do I know the fault is the AVR and not the generator?
Measure output voltage at steady load. If it is low and does not respond to the excitation trim, while windings and rotating diodes are healthy, the AVR is the suspect. A cross-test with a spare AVR confirms it in minutes.
Can the voltage be trimmed after installation?
Yes. Most of these regulators have a voltage and a stability trim pot. Set them at no load to the site nominal voltage, then verify under load before signing off.
Related parts
See the spare parts catalogue or request a quotation quoting the equipment reference. Third-party trademarks are cited for identification purposes only.
