Advice on how to diagnose the cause of a power outage and how to turn the power back on
When the electrical power goes out in your house, the first thing to do is determine the source of the problem. Is it in your home’s electrical system or with the utility company’s electrical supply to your home?
If the electrical power is unavailable in your entire house and your neighbors appear to have lost power too, call the utility company.
If any of your home’s electrical power works—receptacles or lights in another room, for example—the problem is with your home’s system.
The latter problem is generally caused by an overloaded circuit, but can also be caused by a short circuit or loose wiring. Generally figure that the problem is an overload if it occurred when someone was using a hair dryer, electric heater, air conditioner, or some other electrical appliance that draws a lot of current.
As discussed in The Main Electrical Panel & Subpanels, circuit breakers (or fuses in older electrical panels) automatically shut down an electrical circuit if too much current flows through wires or if the electrical system has a failure.
If the circuit is overloaded, a circuit breaker should trip or a fuse should blow.
If a GFCI receptacle or circuit breaker is part of the non-working circuit (typically in a kitchen, bath, or outdoors), you can often solve the problem by simply pushing the reset button on the GFCI device.
If the circuit that isn’t working doesn’t include a GFCI device, check the electrical subpanel or main panel that serves the circuit. Look to see whether one of the circuit breakers has flipped off. This may not be as obvious as it sounds. A tripped circuit breaker won’t necessarily be in the “Off” position—it may be halfway between “Off” and “On.”
Turn off or unplug everything from the troubled circuit. Then reset the breaker. Turn it all of the way to “Off” and then to “On.”
If your system is protected by a fuse box instead of an electrical panel with circuit breakers, replace the fuse that is “blown.” Look for aa broken element beneath the fuse’s glass surface. It’s best to use a tool called a fuse puller to remove and replace the faulty fuse. Do not touch the metal parts with your fingers!
If the circuit blows immediately after you reset the breaker or change the fuse, a charred wire or defective device in the circuit will probably need replacement.
If the circuit doesn’t blow, turn the lights back on and plug in appliances one by one to check for the overload or short circuit.
If one device that draws a lot of current seems to overload the circuit, you can turn off other devices when using it, but it is probably a better idea to have your electrical service upgraded. If the lights or receptacles still don’t work, a loose wire is probably causing the problem. In the case of a charred or loose wire, you will need to call in an electrician.
Do not do your own electrical repair unless you are accomplished at and knowledgeable about electrical work.
If you are capable of doing this work, be sure to follow all safety precautions:
• Never work on live electrical wires. Always shut off the circuit first.
• Do not stand in water or on a damp floor, even when working on low-voltage wiring such as telephone wires.
Lights Dim When Appliances Kick On
When this happens, the cause is too many electrical devices drawing power from one circuit. If plugging some devices into receptacles on other circuits doesn’t solve the problem, you may have to upgrade your home’s electrical service panel.
For today’s electrical needs, a main electrical panel should deliver 100 amps of power or more; 150- or 200-amp services are even better for homes fitted with generous lighting and electrical amenities.
A main panel sized smaller than 100 amps may be overloaded, which can cause lights to dim when appliances kick on and may lead to frequent home power outages. If this is the case in your home, talk with an electrical contractor about installing a new, larger electrical service panel.
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