Inside the box, you'll find things like circuit breakers, busbars, terminal blocks, and wires. These parts control and distribute the electricity to different circuits safely. Find the grounding bar or PE bar Open the distribution box and find the position marked with the grounding plate or PE letter. It is not intended to be a comprehensive design guide; however, many features of design are explained herein. In modern electrical systems, cable distribution boxes (also known as electrical distribution boxes or distribution boxes) play a crucial role as the key hub for managing, distributing, and protecting circuits.