The R438 Voltage regulator is powered by up to two auxiliary windings that are independent of the voltage match circuit. The first winding has a voltage that is equivalent to the alternator voltage while the second winding has a voltage that is equivalent to the stator current.

Power supply voltage is filtered and rectified before use by the Leroy Somer R438 monitoring transistor. This ensures that distortions generated by the load do not affect the regulation. The Permanent Magnet Generator (PMG) is fitted at the rear and connected to the Leroy Somer R438 AVR. The PMG ensures constant voltage supply to the AVR, which is independent of the main alternator winding. The result: the machine has a short circuit current capacity and adequate protection from load generated distortions. To monitor and correct the alternator, the AVR adjusts the excitation current.
The AVR R438 comes with a standard Load Adjustment Module (LAM) system. This system decreases the rotation speed of the generator when a load is applied. When the load goes below the present frequency threshold, the LAM triggers a drop-in voltage to approximately 13-25%.
Key specifications:

Phase to phase voltage sensing
Compatible with other modules to give additional functionalities
Electronic protection
Voltage regulation of +/- 0.5% at steady state and constant speed
Electronic protection functions (overload and short circuit)
In-built LAM system to cope with increased loads applied to the engine
Rated overload current of 8A – 10s
Built to withstand high-level vibration and harsh weather
Close loop control of the generator’s output voltage by controlling the exciter field current.

Key Points:

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Original Leroy Somer R438 AVR
P.N AEM110RE017

Largest AVR Stock in USA