Over Voltage refers to voltage higher than the voltage at which equipment is designed to operate most effectively. It causes a reduction in equipment lifetime and increases in energy consumed with no improvement in performance. The 16th edition of the Wiring Regulations BS7671 makes the following statements in relation to overvoltage: “A 230V rated lamp used at 240 will achieve only 55% of its rated life” and “A 230V linear appliance used on a 240V supply will take 4.3% more current and will consume almost 9% more energy.” Various technologies can be used to avoid overvoltage, but it must be done so efficiently so that energy savings resulting from using the correct voltage are not offset by energy wasted within the device used to do so. Reliability is also important, and there are potential problems inherent in running full incoming power through electro-mechanical devices such as automatic voltage controller.
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