Final answer:
Distribution transformers are often equipped with tappable windings to maintain consistent secondary voltage across various locations despite variations in primary voltage, thanks to the transformer equation.
Step-by-step explanation:
Some distribution transformers are supplied with tappable windings in order to provide the same secondary voltage at different locations on the system where the primary voltage may not be the same. The reason for this is based on the transformer equation, which relates the primary and secondary voltages to the number of turns on their respective coils. By adjusting the number of active turns on a transformer's secondary coil, the output voltage can be regulated even if there are fluctuations or differences in the primary voltage.
This feature is essential for maintaining consistent voltage levels in power distribution systems, ensuring that end-users receive electric power at the correct voltage levels for their equipment. The transformer equation is given by the formula: (Secondary Voltage) / (Primary Voltage) = (Number of turns in secondary coil) / (Number of turns in primary coil). By having tappable windings, transformers can compensate for variations in the primary voltage, making them multipurpose and suitable for various locations and voltage requirements.