What is a principal justification for having a good one-line diagram?

A good one-line diagram is crucial in promoting electrical safety and thereby saving lives. This type of diagram provides a simplified representation of the electrical system, showing how components are interconnected. By clarifying the layout of circuits, voltage levels, and safety devices, it enhances situational awareness for workers who are tasked with maintaining or troubleshooting electrical systems. This reduces the risk of accidents, such as electrical shocks or shorts, by ensuring that all personnel have a clear understanding of the system they are working with, including potential hazards.

The primary goal of safety in electrical work is always the prevention of injury or fatalities, making it paramount that workers have access to accurate and clear diagrams. This visual tool becomes especially vital in emergency situations, where quick and informed decisions must be made. By providing information about where to isolate power or identify potential hazards, a one-line diagram directly contributes to safeguarding the lives of workers in the field.

Other aspects like saving time during inspections or enhancing worker productivity are beneficial but secondary in comparison to the critical safety implications that a clear understanding of the electrical system provides.