Reading an SLD is a straightforward process once you understand the basic flow. You should always start at the top of the diagram, where the incoming power source (like the utility feed or a generator) is located. From there, you follow the lines and symbols downstream, tracing the path of the electricity as it moves through various components like transformers, switchgear, and protective devices, until it reaches the final loads.

This top-to-bottom or left-to-right approach helps you understand how voltage is transformed and distributed throughout the system. By following the diagram, you can identify the protective devices that safeguard each part of the system and locate the correct point to de-energize a circuit for safe work.