Have you ever wondered how the utility company knows how much power you used each month? This basic article explains how it all works with an electric meter.
To understand what is happening with power measurement, you first need to know where the electricity comes from that powers your home. Knowing how an electrical system works, makes explaining power consumption and measurement much easier.
The utility company often connects their power lines to the weatherhead on you electrical power pole. It is connected to a pipe that connects to your electric meter. This the the device that will measure the power your electrical system of your uses throughout the month.
The electric meter not only measures power, but is one way the utility company can disconnect power from your home. The electric meter is a glass-encased metering device. It's almost like an oversized mason jar. Since it is clear glass, you can see through the glass. Inside, the glass houses the measuring devices that include dials and wheels on the older model meters.
Usually, there are 5 dials that measure kilowatts and a large rotating wheel that sits below them. These type meters must be read by the owner of the property or the utility company will read it for you, sometimes for a charge.
The newer electric meters are digital and have an added feature to them. These devices are actually read from the utility companies office. My understanding is that a signal is sent down the line from the electric meter to the utility company that identifies your particular meter.
Electric meters read kilowatt hours. To simply that, 1 kilowatt hour = 1,000 watt hours. To simply that even further, if you turn on a 100-watt light bulb for ten hours, you'll consumer 1 kilowatt of power. 100 watts x 10 hours = 1,000 watt-hours or 1 kilowatt, since kilo = a thousand.
Each month you read the dial, there are five places to record your readings. To read the electric meter dial, start with the number digit on the left and read towards the right.
Let's say the reading is 02050. Your write these numbers down on your utility bill in the five spaces provided. Now to determine how much power you used since last month, simply subtract the reading from last month from this month's total kilowatts. It will look something like, 02050 - 01050 = 01000 kilowatt hours. That means you used 1,000 kilowatts over the course of the month.
One important thing to remember is that if the dial is between numbers, the reading should be recorded as the smaller number. For instance, if the dial is between the 1 and 2, the reading would be recorded as a 1 until it passes the 2 on the dial.
However, as you will notice when you look at the five dials, the first, third, and fifth dial numbers run clockwise like a clock. The second and fourth dials run counterclockwise. Just be careful when you read these dials to write down the proper numbers so that you're not over-billed.
Here are some more great tips about electric meters and your electrical service and panels.