Distribution System

In power outage situations, restoration crews focus on those repairs that will restore power to the greatest number of customers in the least amount of time. Typically, they begin with main lines (1)--those that can restore power to perhaps thousands of people. Then they move to primary lines that can affect hundreds (3); secondary lines that affect dozens (4); and finally to service drops (5) at individual homes. Here’s how the power flows from the a power plant to your house:

1.	Electricity travels from the power plant over high-voltage transmission lines.
2.	At a substation, the electricity’s voltage is lowered so that it can travel over the distribution system.
3.	Main lines carry electricity to secondary lines.
4.	Service lines carry electricity to neighborhoods.
5.	Service drops carry electricity from pole-mounted transformers – which lower the voltage again – to your home.

Note that if a substation is damaged, all customers “downstream” from the substation may be affected. In addition, even when primary lines have been repaired, you may have a problem with your secondary line, your transformer or the service drop to your home that keeps you in the dark even when your neighbors’ lights are back on!