What is the purpose of the transformer installed between Panelboard DD and Panelboard G?

The purpose of the transformer installed between Panelboard DD and Panelboard G is to supply step-down voltage. This means that the transformer decreases the voltage level from the primary side (input) to a lower voltage level on the secondary side (output), making it suitable for its load or for further distribution.

In electrical systems, particularly in commercial and industrial settings, transformers are often used to match voltage levels. For instance, if the incoming voltage is higher than what the load or equipment connected to Panelboard G requires, a step-down transformer ensures that the voltage is reduced to an appropriate level, thus protecting the equipment from potential damage due to high voltage.

Other options such as supplying step-up voltage, converting AC to DC, or isolating circuits, while they each have specific applications in electrical systems, do not accurately describe the function of a transformer in this context. A step-up transformer is used to increase voltage, while converters would not be involved in simply managing voltage levels. Additionally, isolation transformers serve a different purpose, primarily focused on safety and noise reduction rather than voltage adjustment. Therefore, the correct understanding of the transformer's role is foundational to managing electrical systems effectively.