Why Does The Power Go Out When It Rains?

During the summer months there are several things that can cause the power to fail. These power failures, or blackouts, typically occur during rain or wind storms. Here are some things that can cause this to happen.

Power lines are typically kept in place on poles with porcelain bushings and insulators. During periods of heavy rain the insulation properties of the porcelain bushings, insulators, and switches can be reduced. These devices can also crack or break allowing water to get in and cause a power shortage. This causes a fuse to blow which results in a power failure.

The wind that accompanies rain storms can cause trees to sway, branches to break, or whole trees to be knocked over. These events can cause anything from brief interruptions to the power (noticeable when the lights flicker) to full blackouts. When a tree comes into contact with a power line the electricity is automatically cut and restarted. If the tree is no longer touching the power line then the power stays on and we just notice a quick flicker. If the tree is still touching the power line then the power stays off and a crew is sent to fix the problem.

In prolonged rain storms water can accumulate and cause flooding. Flooding can damage both overhead and underground electrical equipment. In either case excessive water buildup can cause a short in the electrical equipment which leads to a blackout.

Brief power interruptions are generally harmless except that they can damage sensitive electronic equipment. Even a brief power flicker can cause a computer to automatically shut down. This can lead to loss of unsaved data, corrupt files, or even damaged hard drives. To avoid this it is best to shut off electronic equipment during storms or to connect your equipment to an uninterruptible power supply (UPS) . These devices offer both surge protection and backup power for when the power flickers or goes out completely.

To prepare for prolonged power outages it is useful to have candles, flashlights (with fresh batteries), a gas powered lantern or stove, or even a power generator. A power generator can be used to keep the fridge running, keep the lights on, or power a TV or radio to allow you to stay up to date with the power restoration process.

While the summer rains are always welcome to water our lawns and gardens they can bring power interruptions and failures. While there isn’t much we can do to prevent these power failures from occurring we can always make sure we are prepared so that when they happen they are only minor inconveniences or even a pleasant break from the hot weather.

1 Comment »

admin on August 22nd 2010 in Home power

One Response to “Why Does The Power Go Out When It Rains?”

  1. Monex Investigation responded on 19 Dec 2010 at 1:24 am #

    Virtually all power-line noise originating from utility company equipment is caused by a spark or arcing across some power-line related hardware. While not power-line noise a gap can exist in the commutator of a motor.