Making an Electrical Map of Your Home
Why Make An Electrical Map?
Making a map is a simple process, if a tad time consuming, but spending an hour one afternoon will save you a lot of time and energy later when you need to disable or enable power to a particular area or fixture in your home.
Making An Electrical Map
Start by removing one fuse or tripping one breaker and go through your house and test the overhead lights and other appliances attached to switches, as well as all outlets by attaching something portable to them (a small electric clock is handy).
One of your hidden kitchen outlets will be obvious because your fridge will be off. Mark which rooms and/or outlets are affected by that breaker until you have a list of every switch and outlet in your house, and post it inside or near the circuit box service panel.
Don’t be surprised if a circuit feeds sections of the house that aren’t next to each other, or if two fuses serve different sides of one room; sometimes electricians run wires hither and yon.
Do each fuse/breaker until you have your house mapped. This will help you pinpoint which areas need work or are being overloaded. For example, if every time you use your hairdryer it causes a blown fuse or trips a breaker, the dryer may be pushing that particular circuit over the edge, and you may need to switch to a different circuitry grid (it will be one of the rooms that continues to have power) or buy a less powerful hair dryer.
The blown fuse or tripped breaker protects your home by shutting down overloaded circuitry, and keeping it from getting too hot and creating the risk of fire. If it happens frequently, and in particular if you smell something like burning plastic, which is the casing on wires that are getting too hot, it’s time to call an electrician.
Once you have your house’s electrical system mapped, it will be possible to disable the power to specific lights, receptacles, outlets and switches without turning off the power to your whole house. To turn off the power to an area that you have mapped, simply trip the switch or unscrew the fuse serving it at your breaker box.
Tip: If you haven’t mapped your house and want to determine which fuse/breaker serves an outlet or switch, plug in a radio and turn the volume up enough that you can hear it from your breaker box. Flip switches or unscrew fuses until it goes silent.
Testing, Testing
Testing is an important step to home electrical repairs. Tests show if something that is giving you problems is wired correctly with respect to the natural laws of electrical currents and if it is completely free of current ("cold") and safe to work on.
Tip:Even after you disable the power to an outlet, switch or built-in light, residual current may still be flowing through the circuit. To make sure what you want to work on is cold, use an EMF tester or a standard 120-240 volt range circuit tester on outlets.
