In this howto there are procedures that will expose you to your home’s electrical system. If you have any doubts about your ability to work with home electrical systems then you should call a professional electrician.
A Friend is asking about a couple outside outlets that aren’t functioning and they have checked a few things but haven’t been able to find out why the outlets aren’t working or what they might need to repair.
The first thing about outside outlets is that if the home is reasonably new then the outlets are required to be on GFCI circuits. This means if there is a short or problem then the outlet will shut off hopefully before the person using it gets harmed.
When it comes to the location of the GFCI protection it could be in a few places. It could be on the outside outlet or the outside outlet could be on an inside circuit such as one providing power for the bathroom or kitchen which also needs to be GFCI protected and one of those outlets might have the GFCI outlet circuit breaker. The final place would be GFCI protection in the electrical box and this is becoming more common due to recent changes in the Electrical Code.
If someone was using the outside outlet and they tripped the GFCI circuit breaker on the outlet then it would shut down the entire circuit. This means that you will easily see that outlets in the kitchen or bathroom are not working and maybe a reset of that breaker will fix the problem after the outside tool has been unplugged. Either that or you would check your circuit breaker box and see if any of your breakers have been tripped.
Our friend has checked all of the GFCI outlet Breakers and the main circuit breaker box for any tripped breakers and has not found any. The next step would be to inspect the outside outlet for any damage.
With an appropriate tester inserted into the outside outlet you should be able to see if the outlet is getting any voltage. You may also be presented some troubleshooting information. If you see no voltage or information then you can use the sniffer probe that works with the outlet tester to double check which circuit breaker this outlet is on. When you have problems like this never take the word of some hand written notes on your breaker box to know which outlet or items are on which circuit. Often they get mixed up or electricians get confused. A continuity tester will test the wires from the outlet to the circuit breaker box. Reset that circuit breaker just to make sure it is functioning and not half tripped.
You can now test that the circuit is being provided voltage through the breaker by checking the positive wire to ground and reading the voltage on the circuit. Whatever the Circuit is rated at is what you should read. A small difference in voltage of a few percent may be acceptable if your power supplier is not providing the best quality to your home but you should not see a 50% or even 15% drop in voltage from the wire connector on the breaker. If you do then you need to replace the breaker.
If you find proper results and find that there is zero voltage when you turn the breaker off then turn it off and move to the outlet that is causing problems.
Sometimes when a short to ground happens such as an outside tool cutting through a power cord, the outside outlet will burn its self out. To check your outlet I suggest that you just replace it with a good outlet but once the power is off to the outlet you can remove the face plate and then visually inspect the outlet. A burnt out outlet often will show actual burns and melting plastic on the outlet and the wires leading to the outlet might also have insulation burnt off them. Other times the outlet might look reasonably clean and just not function.
There are tests for continuity that you can run from the prongs of the outlet to the screw heads where the wires connect but at this point because outlets are so cheap you should simply replace the outlet after inspecting the wires running to it and run your tests again.
Any outlet that fails can not be repaired so replacement is a good solution for diagnostics and repair.
Final Notes
Diagnosing Electrical Circuits does take some experience working with this type of equipment. If you have had limited training then some of the steps such as inserting a tester into the outlet or checking your breakers and GFCI Outlet Breakers and resetting them is something a home owner can do. Also you need to check your state and local regulations as to how much work you can do on your electrical. Normally you can do minor repairs with no problems.
and as first stated whenever you find you are into a project beyond your skill level always get help from a professional.