What does the presence of a "3-prong" plug indicate?

The presence of a "3-prong" plug indicates that the device has a ground connection for safety. The third prong is specifically designed to provide a grounding path. This helps prevent electric shock in case of a fault, where the device could become energized due to a malfunction. The ground connection is critical in ensuring safe operation, as it allows excess electric current to be diverted safely to the ground instead of through a person or causing a fire hazard.

In contrast, low-voltage applications do not necessarily require a ground connection, and a 3-prong plug doesn’t indicate universal compatibility with all outlets since many older outlets do not have grounding capabilities. While some devices might have a higher amperage capacity, the primary function of the third prong is safety through grounding rather than an increase in capacity. This grounding feature is essential for appliances and equipment that could pose electrical risks, making it a vital part of the plug's design.