Distribution transformers' secondary windings are usually configured in which manner?

The secondary windings of distribution transformers are typically configured in a parallel configuration. This arrangement allows for the sharing of load between the windings, which is particularly useful for providing a stable and balanced output voltage to the customer’s electrical system. When transformers are in parallel, they can handle greater total load without overloading any single transformer, enhancing reliability and efficiency.

In the parallel configuration, if one transformer needs maintenance or fails, the other transformer can continue to provide power, ensuring continuous service. This setup also helps in managing different load demands by allowing for easy connection or disconnection of individual transformers as needed.

The series configuration, where components are connected end-to-end, is not suitable for distribution transformers because it would not maintain a stable output voltage and could lead to overload situations. Star and delta configurations are primarily used for three-phase transformers, but these configurations pertain more to the primary side of the transformer or specific applications rather than standard distribution transformer's secondary windings in typical one or three-phase systems.