Sx460 Stamford Automatic Voltage Regulator

Sx460 Automatic Voltage Regulator (AVR) is a half-wave phase-controlled thyristor-type device integral to the excitation system of a brushless generator. It regulates generator voltage and includes protection against under-speed and sensing loss. It derives excitation power directly from the generator terminals.

The Sx460 uses efficient semiconductors to ensure positive voltage build-up from residual levels. It connects to the main stator windings and the exciter field windings. This enables closed-loop control of the output voltage with a load regulation accuracy of +/- 1.0%.

The SX460 AVR powers itself from the main stator and samples voltage from the output windings for voltage control. Based on this sample voltage, the AVR adjusts the power to the exciter field and the main field. This maintains the generator’s output voltage within specified limits and compensates for variations in load, speed, temperature, and power factor.

A frequency-measuring circuit continuously monitors the generator’s output. It provides under-speed protection by reducing the output voltage as speed drops below a preset threshold. You can manually adjust the under-frequency roll-off point (UFRO) during factory settings and change it to 50 or 60 Hz in the field using a push-on link selection.