At what setting should tap changers be configured for normal operation?

The tap changers on transformers are used to regulate the voltage output by adjusting the turn ratio of the transformer. For normal operation, tap changers are typically configured to operate at a setting that maximizes efficiency and voltage regulation under standard load conditions. A setting of 100% indicates that the transformer is functioning at its nominal voltage, providing the optimal performance expected during regular usage.

When operating at this setting, the transformer can provide the expected voltage level to the distribution system, ensuring that electrical equipment operates effectively and safely. This is crucial in maintaining the stability of the electrical grid and ensuring that all connected devices receive a reliable power supply.

Other settings, such as 50%, 75%, or 125%, may be used for specific situations where adjustments are necessary due to changing load conditions, but they do not represent the standard operational level. Each of these alternative settings could lead to under-voltage or over-voltage conditions, which might harm electrical devices or reduce overall efficiency. Thus, 100% is considered the baseline for normal operation in the context of tap changers.