Feeder voltage regulator accuracy standards

IMPROVED ACCURACY of automatic feeder voltage regulators will permit increasing feeder load or increasing feeder length without exceeding specified limits for consumers´ voltage under varying conditions of load, temperature, frequency, and so forth. To obtain maximum benefits in system design and operation from increased regulator accuracy, distribution engineers must know what limits of error to expect for their operating conditions. The standards for “Accuracy of Control Devices for Induction Voltage and Step Voltage Regulators,” which have been included in the proposed revision of ASA C57, “Standards for Transformers, Regulators, and Reactors,” will provide a practical basis for specifications. The purpose of this article is to aid distribution engineers in gaining a working knowledge of these new standards.