Stamford PG36658Q2 Automatic Voltage Regulator

The Stamford PG36658Q2, also known as the SX460 Automatic Voltage Regulator, is a self-excited analogue AVR designed to regulate excitation in Stamford brushless generators to maintain a stable output voltage. It is a two‑phase sensing device that couples the main stator windings with the exciter field to form closed‑loop voltage control, a configuration commonly used on Stamford UC22 and UC27 alternators. The SX460 delivers voltage regulation within approximately ±1.0% under steady‑state conditions and includes protections for under‑speed and sensing loss to guard against improper excitation during abnormal operation, with a remote voltage trim option available to adjust the regulator’s setpoint without direct access to the AVR. The PG36658Q2/L designation identifies the factory part number for this SX460‑based AVR. Stamford notes that the SX460 is obsolete and has been superseded by the AS440, so genuine replacements are typically sourced through authorised Stamford AvK dealers for maintaining older gensets. In installations that originally used SX460, this AVR provides controlled excitation to support stable voltage during load changes and helps protect connected equipment from voltage fluctuations.