What must be part of a project installer’s documentation for larger installations?

A one-line diagram is an essential component of a project installer’s documentation, particularly for larger installations. This type of diagram provides a simplified representation of the electrical system, indicating how the various components are interconnected. It helps in understanding the system design, functionality, and key operational elements. By using standardized symbols and a single-line approach, it communicates vital information without overwhelming detail, making it easier for both installers and inspectors to verify and understand the electrical layout.

Having a one-line diagram is crucial for ensuring safety and code compliance in larger projects. It allows for clear communication among all stakeholders, including engineers, electricians, and inspectors, about how the system is designed to operate. Additionally, it serves as a valuable reference for troubleshooting and maintenance, outlining the path of electricity and major components like transformers, switches, and protective devices which might not be as easily visualized in more complex presentations of the system's layout.