This comprehensive guide will walk you through the basics of electrical blueprints, the meaning of common symbols, techniques to interpret wiring and single-line diagrams, and practical tips to avoid mistakes. Knowing your distribution box helps you see which breaker does what. Check and update your labels often. Use. After reading and studying this handbook, electricians (or would-be electricians) will have a firm grasp on the many symbols used in electrical diagrams. In particular, you will understand how to read and interpret a wide variety of electrical diagrams and plans, and how to use them together for. In order to trace control system problems to the core, the ability to read and interpret various resources, from facility-level diagrams to machine-level wiring layouts, is critical. This. An electrical diagram is a graphical representation of an electrical system that shows how the components are connected and how the current flows through the system.