Simple Electrical Repairs

As a long-time do-it-yourselfer, I'm used to working with electricity.  I've been zapped a few times (that's pretty much always a consequence of taking shortcuts, or doing something that you KNOW is unsafe), but nothing too serious, and, if you're reasonably handy, there's no reason you can't do many electrical repairs yourself.

First, a caveat:  In most cases, you are allowed to do your own electrical work, but you still must follow the applicable codes, and you may need a permit.  Contact your local building and safety department for clarification.  If you're not comfortable doing the work, don't do it - saving a few bucks is not worth taking foolish chances.

If you're sufficiently scared, let's look at a few common problems, and how to fix them.  Before you start, you'll need a few tools - Wire Cutters, Wire Stripper, Screwdrivers (Flat Blade and Phillips), long nose pliers, and a voltage tester (for more complex issues, you may need a multi-meter, instead of a voltage tester).

Replacing a light switch (or installing a dimmer), is simple.  Let's assume you're replacing a standard wall switch with an identical one.  Here's what you do:

• Shut off the power at the circuit breaker.  Don't assume the labels on the box are correct - test it first.  Experienced electricians will sometimes work on a "hot" circuit, but you shouldn't.  When you turn off the breaker, lock it out so no one can turn it on (or at least put a note on it, to warn anyone that you're working on it).
• Remove the plate cover, and take out the two screws holding the switch in the box.  There should be enough slack in the wires to allow you to pull the switch away from the wall.
• There will most likely be two black wires hooked up to terminals on the switch - these are the power leads.  One will supply power to the switch, and the other will send power to the light or appliance to be energized.   Depending on your home's wiring, there may or may not be a green or bare ground wire attached to the switch.
• Remove the wires from the old switch.  There are two methods that are typically used to hook the wires up to the switch - they'll either be hooked up with screws, or inserted through holes in the back of the switch and retained with spring clips.  If the latter method us used, it's easiest to just cut the wires flush with the switch body.
• Strip the insulation off the wires, and connect them to the switch.  In most cases, it's best to use the screw terminals - bend the wire in a half circle around the screw in a clockwise direction, and tighten securely.  
• Carefully push the switch back in the box, being careful to avoid loosening the wires.  Tighten the screws to hold it in place, and reinstall the plate cover.  Turn on the power, and test it - you're done!

If you have three wires (not counting the ground wire) hooked up to your switch, it probably means you have a three-way switch.  You'll need to replace it with a new three-way switch, and you should hook it up the same as the old one.  If you replace one three-way, I think it's best to replace the other one at the same time.

Replacing an outlet is almost exactly the same, except you'll need to connect an extra wire.  After shutting off the power and removing the old outlet, look at your wires.  In most cases, there will be three wires hooked up to the outlet - Black, White, and Green (or Bare).  It's Very important to hook these wires up to the right terminals on your new outlet.

• Look at your new outlet - the screws on one side will be silver, and the other side are brass.  The black wire is the "hot" wire, and it should be attached to the brass side.  The white wire is the "neutral" wire, and is hooked up to the silver side.  If you mix up the hot and neutral wires, the outlet will still work, but the polarity will be reversed, and could be dangerous.  If you're not sure which is which, get help to determine which is which.  If you have a third wire (green or bare), it will be attached to the green wire on the outlet.

The other thing that's important is to make sure your wire size is adequate for the outlet.  Wire size is determined by gauge - the smaller the number, the larger the wire.  For a standard, 15 amp circuit (a standard outlet and a 15 amp fuse or circuit breaker), 14 gauge wire is adequate. If you have 12 gauge wire, you can use  20 amp breakers and outlets.  Please note - if you use a 20 amp breaker, you MUST use at least 12 gauge wire and 20 amp outlets.  It's OK to use a smaller breaker and outlets with the larger wire, but not the other way around.

 Replacing a light fixture is not difficult, and it can be a great way to dress up a room.

• Kill the power, and remove the old fixture.  Again, you should have a black (hot) wire and a white (neutral) wire.  You may or may not have a green or bare ground wire.
• Check to make sure the junction box is firmly attached, and able to support the weight of the fixture.  If you're installing a ceiling fan, you must have a metal box that's firmly attached to a ceiling structural beam.
• Strip the wires, and connect the black wire from the new fixture to the black power wire using the proper size wire nut.  The fixture will probably have wire nuts included, or you can pick them up in any hardware store.  They're color coded, and the package will list what size/quantity of wires for which each is designed.  To use the wire nut, just lay the two wires together, and screw it on securely - test it by pulling on the wire.  Repeat for the white wire.  The ground wire, if available, will usually be connected directly to the fixture with a screw terminal.
• The new fixture will have a strap that attaches to the junction box.  Make sure it's securely attached, then attach the fixture to it per the included directions.  Ceiling fans will have specific mounting directions, so you'll need to follow them carefully.
• When you're done, check to make sure you're putting the proper wattage bulb in the fixture, then test it.  Do not exceed the recommended wattage, or you could cause a fire.

Correcting a circuit breaker or fuse that repeatedly trips is a little more complicated.   Unless you're experienced, you may need some help.  You'll want to add a circuit if you find you're blowing fuses or tripping breakers, or if you are adding a room or appliance that needs it's own dedicated electrical supply.

If you blow fuses, you need to check to see how many amps you're using.  For this, you'll need a digital multimeter that has a clamp-on inductive amp meter.  With that, you can measure the amount of current being used (measured in amps).  A standard circuit has a 15 amp breaker.  If you put the meter around the wire leading from the breaker, it will tell you how many amps you're pulling.  Put it on there and check, then go turn everything on that is on that circuit - if you're close to 15 amps, you've got too much, and you should change things up.

If you've just started to blow your breaker, it's possible you have a short,a bad breaker, or a bad appliance that is causing the problem.  To test for this, turn everything off that works on the suspect breaker. Check one thing at a time, and see if something is using more power than it should (everything should have a label showing it's wattage rating).  Volts * Amps = Watts, so something that is rated for 800 watts should use a maximum of around 7 amps (7*115 =805).  Most of the time it will use a shade less that it's rated wattage.  Most likely,  you'll find something that either blows the circuit right away or uses more power than it should.  If you find it, repair or replace it - adding a circuit won't solve the problem.  If you can't find a problem, you probably just have too much on one circuit.

If you're lucky, you'll have an empty spot in your breaker box.  If you do, you can just buy a new breaker (in this example, a 15 amp single pole), and install it in the box.  Breakers are made to fit specific boxes, so you'll have to get exactly the same thing that's in yours.  Most of them just snap into place - if you can't see how it works, ask at the hardware store and they'll tell you.  You can snap in a new breaker without killing the power to the whole box, but it's safest to turn off the main breaker at the top of the box while you're messing around in there.  Even with the main breaker off, there will be power at the terminals where the power line comes into the house.  Use your meter and carefully check for voltage, so you know where it is.

After you put your new breaker in, you'll need to run your wires to it. You'll want to run romex cable all the way from the main panel to your new circuit.  Remember, use at least 14 gauge wire for a 15 amp breaker, 12 gauge for a 20 amp.  In any case, run cable that has a separate ground wire, even if your existing wire doesn't have the ground.  If the area you're running power to is unfinished, or if you have access to an unfinished area below or above it to run the wire, it's pretty easy.  If you have to pull cable across a finished area, you may need professional help.

In any case, run your cable, and hook up your outlets or lighting fixtures as described above.  Every junction should be in a junction box, and any cable run should go inside the wall or ceiling.  Anything run along the surface of a finished wall should be in conduit.  The black wire should always be hot (hooked up to the breaker), and the white wire is neutral.  If you look in your panel, you'll see a buss bar with all the white wires connected.  In most cases (but not all), the ground wire will be hooked to the same bar. 

As I said before, if you're not comfortable working with electricity, get a professional.  If you're not intimidated, however, there are many simple repairs you can safely tackle yourself.  Start off small, shut off the power before you start, and you'll be able to repair most of the issues commonly found in the home.