When Power Goes Off, Check for Blown Fuse : Electrical Repair: Prevent circuit overloads by balancing the use of home appliances. Learning how to reset circuit breakers and replace fuses is simple.

<i> Abrams is a Los Angeles general contractor and a free-lance writer</i>

If you are like most of us, you have probably experienced an electrical power failure in your home, either from an electrical storm, earthquake, power company equipment failure or a circuit overload.

There is not much any of us can do about the first three causes, but it is very important to know how to prevent overloading household circuits and how to reset circuit breakers or replace fuses when they blow.

Preventing circuit overloads is primarily a matter of balancing appliance use, especially appliances that produce heat. Do not, for example, use a toaster at the same time that a coffee maker is in operation.

Do not use a hair dryer while your electric iron is being used. All household circuits are designed to handle a certain safe electrical load and will shut down when they are overtaxed. Devices that produce heat draw a great deal of current, so using them simultaneously should be avoided whenever possible.

So let’s say you have blown it (literally) and overloaded a circuit, causing the power to go off. Now what, call an electrician? No, not yet. You might be able to fix it yourself in a few minutes. Here’s how.


First, you must find your power box. If you are in a house or an apartment building of less than 10 units, chances are the box is at the back of the structure. A good way to find it is by looking up at the power lines from the utility pole.

The box is usually directly below the point at which the lines attach to the building. In larger apartment buildings and condominiums, each unit usually has its own circuit box, normally found on a wall behind a bedroom door.

Once you find the power box you have to determine which circuit has blown. If you open the box and find circuit breakers (i.e. switches that move left/right or up/down) you may notice that one of the “toggles” is out of line with all the others. To reset it, move the toggle to the full “off” position, then back to “on.” If it is not clear which one is tripped, simply reset all the breakers in the box.

If, upon opening the power box you find fuses (i.e. glass “dials” that unscrew like a light bulb), look for a dark or burnt spot in the center of any of the fuses and replace it with another fuse of the exact same amperage (always stamped on the bottom of the fuse, e.g. 15, 20, 30). Blown fuses sometimes look perfectly good, so if this is the case, you must replace all of them one by one with a good spare, each time checking if the power comes back on.

If, when checking the circuit breakers or fuses you find a breaker that will not reset or a fuse that blows out immediately, it could be the result of a defective appliance or fixture causing a short circuit.

To determine if this is the case, unplug everything in the room(s) where the power is out and then recheck the breakers or fuses. If the power does come on, you can conclude that your house wiring is OK and the short was caused by one of the lamps, radios, TVs or other items that were plugged in. By plugging each item in one at a time and noting at which point the power goes out again, you will determine which one is at fault.

If you follow the steps above and are unsuccessful, repeat them, only a little more slowly the second time. Sometimes a circuit breaker or fuse will not “catch” immediately after tripping. And, naturally, be sure that any spare fuses you try are good.

Of course, it’s always better to avoid electrical problems by using appliances one at a time, but sooner or later even the most careful among us will overdo it.