2. THE BASICS: AUTOMATIC VOLTAGE REGULATOR SYSTEMS
In a perfect world, utilities would deliver power without voltage swells or sags. But the reality is that supply voltage is often higher than normal (a swell) or lower than nominal (a sag) over extended periods of time. To address these unacceptable power deviations, it is common to install an automatic voltage regulator (AVR) either before or after the step-down transformer. In doing so, it is important to determine the effect that installing the voltage regulator will have on existing system components.
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