So, whats a Watt?

A watt is as familiar to the average American as the electrical plug in the wall.  He knows it’s there and that some things take more watts than others and that watts cost money in the monthly “electric” or “light bill” but most people don’t know much beyond that.  Maybe you don’t either. 

A watt is simply a measure of the pressure and rate of flow of an electrical current.  Whew.  Watts are simply the voltage times the amperes…the pressure times the rate of flow.  If we know that the current is 5 amps (5 amperes) in a 120-volt circuit, we know the wattage involved is 5 x 120 or 600 watts.

Most times we will know that a light bulb or another appliance is a “100-watter”.  We usually are told by the manufacturer what the wattage requirement is on a 120-volt line.  We don’t hear about the amperes as much.  But you can determine the amperes by dividing the 100 watts by 120 volts to determine that for the 100-watt light bulb on a 120 volt circuit the current will have to be about 0.83 amps.
 
Chances are the amp rating you’re most familiar with is your home fuse box or circuit breakers.  You might have a 15-amp protective device on an electrical circuit in your house.  Now you know how much “load” you can put on that circuit.  You know it’s a 120 volt line that can only take 15 amps before the fuse or breaker blows.  Since volts times amps equal watts, you know that 120 times 15 means that 1800 watts is the most you can put on that line at one time.  Now you can count up the light s, appliances, air conditioners, or what-have-you that you might be thinking of to put on that electrical circuit before you plug them in and risk blowing a fuse or tripping a circuit breaker.