Tuesday, January 22, 2008

from the power plant to your house

Your local power plant generates a great deal of electricity. It has to travel a very long distance to get to your house. If the electricity left the plant at 240 volts it would not make it.

They generate it at thousands of volts and they do something else. They generated it as alternating current.

You have probably heard of AC and DC current. But do you really know the difference?
First let’s mention DC or direct current. This is current like that from a battery. It flows in one direction and one direction only. The current goes direct to the source.

AC or alternating current does just that. The current changes direction 60 times a second.
This gives it a pulse like action and makes it better for long distance travel. This is done by an AC generator (alternator). Without getting too technical, let’s just say that it is set up to alternate the current as it spins.

Let’s say that the AC power leaves the plant at 14 thousand volts. Most times it will pass through a relay station to boost the power. When it gets to your house it is still 14,000 volts. So now we have to change it to 120 volts house current. This is accomplished by transformers. They transform the electricity either lower or higher.

Here is the basic principle of transformers. Take two coils of wire in close proximity.
One coil has 100 turns of wire and the other 50. If the electric current is passing through the 100 turn coil it will transfer itself to the 50 turn coil and when it comes out the pressure or voltage will be half of what it was.

And this works in reverse also. If the above situation was reversed the voltage would be doubled. Transformers can either lower (buck) or raise (boost) the voltage.

On the electric pole near your house is a transformer. They usually feed about three houses. The electricity from the transformer comes to you in two 120 volt wires (black) and one neutral wire(bare). This service wire is also called a triplex for that reason.

Power comes from the transformer to the rain head and then to the meter can, where the electric meter is located. It travels from the meter to your main breaker box. Some residences, like mobile homes, have a main box outside with a 100 or 200 amp breaker and another main box inside.

In this way, power can be shut off and the mobile home moved safely.

We have followed the power from the plant to your house.

Electric power for your home is AC current because it travels better than DC. The basic principle of transformers is wrapped up in the number of turns in a coil of wire. Buck transformers lower the voltage and boost transformer raise it.

Your power comes to you (from your transformer) in the form of a triplex with two 120 volt wires and one neutral wire. Mobile homes usually have a main breaker box outside as well as inside. This is to disconnect power to move the home safely.

Next we will talk about what happens when the power gets to you.

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