What do you do when all the power in the house goes off? Usually this is due to a general power outage in an entire neighborhood or district, but sometimes the problem lies in an individual residential wiring system.
The first step is to see whether the outage is a general power outage or restricted to your home. If it's nighttime, look around the neighborhood to see if everyone else's lights are off. During the day, call a neighbor to see if others are affected. Or, if you have a circuit breaker main disconnect, check to see whether it has tripped to the OFF position. If the main entrance is wired with fuses, pull the fuse block out and slip the fuses free. Check them with a continuity tester to see if they are still good. With a probe lead touched to each end of the fuse, the tester light will come on if the fuse is good.
If the trouble is a general power outage, all you can do is call the power company. If your main breaker is still in the ON position or both main fuses are good but your neighbors have power and you don't, the fault lies between your main entrance panel and the power transmission lines. The reason could be a downed service drop, a faulty or overloaded pole transformer, or some similar problem. Call the power company; this part of your system is their responsibility. If you find a tripped main breaker or blown main fuses in your main entrance panel, the problem lies within the house and may be serious. Do not attempt to reset the breaker or replace the fuses. The difficulty may be a system overload, using more total current than the main breaker can pass. Or there may be a dead short somewhere in the house.
The first step is to go back through the house and turn off everything you can. Then, if you have a circuit breaker panel, flip all the breakers to the OFF position. Once the breakers are off, reset the main breaker to the ON position. One by one, trip the branch circuit breakers back on. If one of them fails to reset, or if the main breaker trips off again as you trip the branch breaker on, the source of the trouble lies in that circuit. The circuit will have to be cleared of the fault.
If all the breakers go back on and the main breaker stays on, you're faced with two possibilities. One is that something you disconnected earlier is faulty. Go back along the line, inspect each item for possible fault, and plug each one back in. Sooner or later you'll discover which one is causing the problem, either visually or by noticing that a breaker trips off when you reconnect it. The other possibility is systemwide overloading.
This is characterized by recurrent tripping out of the main breaker when practically everything in the house is running but there are no electrical faults to be found. To solve this problem, you can either lessen the total electrical load or install a new larger main entrance panel with new branch circuits to serve areas of heavy electrical usage and help share the total load. This job requires a licensed electrician.
The troubleshooting approach is similar if the main panel has fuses, except you'll need a supply of fuses on hand. First, pull all the cartridge fuses and unscrew all the plug fuses in the panel. Replace the main fuses, and put the fuse block back into place. Then, one by one, replace each fuse or set of fuses until the one that's causing the outage blows out again. This is the circuit that must be cleared. General overloading, however, will cause the main fuses to go out again. If this happens, call in an electrician, who can test for overloading and suggest remedies.