There are a few ways to calculate the power required to run a whole house on a generator. First I would recommend finding out what level of service your house currently has. Most homes have 150A or 200A service. Larger homes could have 300A or 400A service. This number is usually printed on the main breaker in the breaker box. You may have to call the power company to ask them if you are not sure.
If you multiply that amperage (A) number by the voltage (120), you get the maximum service that the power company can deliver to the house. For a 200A service, that would be 24kW. Most whole house generators are 20kW or less, so one could not safely run the entire house on a generator. Most installations only power certain important circuits in the house to get the power requirements below 20kW.
If you know the maximum wattage for your house, the actual use should be much lower than that. If you have a mechanical electric meter with a rotating disk, you can calculate wattage by timing how long the disk takes to make a full revolution. There is a black line on the disk which you can use for this. Most meters have a Kh factor of 7.2, check your meter to make sure. Here is a picture of a meter, you can see the spinning disk in the middle and the Kh factor of 7.2 written on the side:
I took a video showing the rotating disk in the meter.
You can see it takes about 5 seconds for a full revolution.
The equation to calculate wattage is:
(Kh factor x 3600)/ rotation time in seconds = wattage
For this meter:
7.2 x 3600 / 5 = 5,184 watts. That is not bad for 2 air conditioners running, television and lights on and all appliances plugged in. This does not mean that a 7,500 watt generator would be sufficient. This is a steady state value, the peak load when a compressor kicks on or when all of the lights and appliances are on at the same time - ovens, toasters, etc could be much higher.
No comments:
Post a Comment