Even when you understand that you can't overload an electrical outlet or you will have problems, it isn't to figure out why you can't seem to use more than two appliances at one time. In a nutshell, when a particular circuit has too many appliances plugged into it, the circuit will easily short out from use.
Circuits are Either Dedicated or General-Purpose Circuits
You have electrical outlets throughout your home that serve all of your electrical needs. Dedicated circuits feed power to one appliance that uses a significant amount of energy, such as a clothes dryer or stove. A dedicated circuit can also be for a row of outlets, such as those used for small kitchen appliances. In the breaker box, these circuits should be labeled "dryer", "stove", or "kitchen counter." General-purpose circuits are those that feed power to areas in your home where lights, clocks or fans are likely to be plugged in.
Houses in the United States Have Either 15 or 20 amp Circuits
Each circuit in your home is either 15 or 20 amps, and you should only load each circuit up to 80% capacity to avoid problems. This means that with a 15 amp circuit, using 120 volts, should only carry a total load of 1440 watts. A 20 amp circuit can safely hold 1920 watts. This means that if you have your dishwasher running, which requires 1400 amps to run, and you try to run your microwave at the same time (700-1400 amps), you can easily blow a fuse. If you have your microwave and dishwasher plugged into the same circuit and it is only a 15 amp one, you will have problems.
Avoiding Short Circuits in the Home
If you have a lot of appliances that draw significant power located in one room, you have to try and use different circuits for each large appliance. You may have several circuits available in your kitchen, for example, but you will have to test outlets to find the various circuits. Understand that even a toaster oven will use 1400 watts of power, leaving that circuit virtually useless for anything other than lights or clocks. Know what draws a lot of power when it is being used, and avoid using more than one large appliance per circuit.
If you are having a lot of power outages because of appliance usage, consider calling in a professional electrician such as Palmer Electric Inc. that can map out the various circuits in your home for you. Your electrician will be able to help you problem solve, and move outlets to different circuits if necessary.