Maximum load of a breaker panel.

How can I tell the maximun load of my breaker panel? It's a very big one and still have 2 empty spots that I intend to put 2 20-amp breakers in. I wonder if it will go over the maximum load. Thanks.

 

If you are not already overloaded, it is not very likely that adding two 20-amp circuits will push you over the top. This is especially true if your main breakers are 200 amps, and if the two new circuits are just for general lighting and receptacles. Most people would not go to all the trouble to do a demand load calculation just to add two new circuits for intermittent use.

The load on a panel is not determined by the number or size of the branch circuits.

 

It is intended that you can use all the slots. The main breaker would be getting warm if it was loaded. But,,, it really doesnt matter how many breakers are connected to it, what matters is how much current you are using. If the elect water heater was going, you had elect range all on hi, the central AC running, an air compressor in the garage while welding then there would be some concern. The main will let you know if you are severly overloaded. Here is an example. You could put 25 recepticals on one circuit and have something plugged in to everyone of them. As long as you only run 1 or 2 large appliances such as the vacuum at a time you are fine. Only the things that are on and running are using power and somethings use very little. You could have the vac on and the clock and the radio and maybe a light. When you turn the vac off there is very little being used. If you turned 2 vacs on you would be in danger of overloading. If none are on you may only have a bit from other stuff such as the clock running and you could support hundreds of clocks from a circuit. If its hot out and you have AC running you might consider not using the dryer to keep large loads off at the same time.