R438 Avr For Leroy Somer Generator

R438 AVR for Leroy Somer Generator is built to fully replace the original version, same fit, form and function

For both AREP & PMG excitation systems, the alternator voltage regulator is the R438.With AREP excitation,

the R438 electronic AVR is powered by two auxiliary windings which are self-sufficient of the voltage match circuit. The first winding has a voltage in proportion to that of the alternator (characteristic Shunt),

the second has a voltage in proportion to the stator current (compound characteristic: Booster effect).
The power supply voltage is rectified and filtered before being used by the AVR monitoring transistor.

This principle ensures that regulation is not unnatural by distortions generated by the load.

This excitation system consists of a "PMG" (permanent magnet generator).

This is fitted at the rear of the machine and connected to the R438 AVR.

The PMG supplies the AVR with constant voltage which is independent of the main alternator winding.

As a result the mechanism has a short-circuit current capacity and good immunity to distortions generated by the load.

The AVR monitors and corrects the alternator output voltage

by adjusting the excitation current. 50/60 Hz selection via the ST3 jumper.

The LAM system is integrated in the R 438 AVR as standard. Role of the "LAM" (Load Adjustment Module)

On function of a load, the rotation speed of the generator set decreases.