Primary distribution systems consist of feeders that deliver power from distribution substations to distribution transformers. AC power distribution systems are designed to provide electricity to users in the residential, commercial, and industrial sectors in a safe, efficient. The service entrance is a critical component in any electrical system. It is the point where electricity enters a building or property from the utility company's power lines. The service entrance diagram refers to the layout and configuration of the wiring system used for this purpose. Provide a main breaker on each service entrance.
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