If circuits are equipped with a grounded neutral conductor, what can you tap into?

The correct answer indicates that circuits with a grounded neutral conductor allow for the tapping into two-wire DC circuits from at least two ungrounded conductors. This is based on the principle that when dealing with circuits, the presence of a grounded neutral provides a reference point for the voltage, ensuring safety and proper operation of the electrical system.

When working with two-wire DC circuits, the ungrounded conductors provide the necessary voltage, and the grounded neutral allows for a safe return path. This ensures that potential faults do not lead to hazardous situations. Moreover, tapping into such circuits is compliant with safety standards as it mitigates the risk of shock or fire that could occur if an ungrounded conductor were accessed improperly.

In contrast, the other options either limit the types of circuits that can be utilized or do not provide a safe electrical configuration. Single-phase circuits may or may not incorporate grounded neutrals, depending on their design, while the notion of accessing only ground conductors disregards the requirements for a return path in an electrical setup. Three-wire AC circuits typically involve a different configuration that is distinct from the parameters set forth in the question. Hence, they do not align with the details regarding grounded neutral conductors.