What is a key difference between a 3 wire, single phase and a 3 wire, three phase secondary system?

A key difference between a 3 wire, single phase and a 3 wire, three phase secondary system lies in several aspects, including the number of neutral wires, number of hot legs, and voltage availability.

In a 3 wire, single phase system, there is typically one hot leg and one neutral wire. This setup allows for a straightforward power distribution suitable for residential use, providing a single phase voltage supply, often 120 volts or 240 volts depending on the configuration.

In contrast, a 3 wire, three phase system consists of three hot legs and may or may not include a neutral wire, depending on the specific configuration and load requirements. This system delivers power more efficiently and supports a higher overall voltage availability, which is particularly advantageous for industrial and commercial applications. Three-phase systems can provide a more balanced load and reduce the risk of voltage fluctuation, making them preferable for heavy machinery and equipment.

Thus, the correct answer encompasses all these distinctions, highlighting that each of these characteristics plays a significant role in differentiating the two types of systems.