Installing a Light Fixture

If you are intending to install a light fixture by yourself, it might be good to know that the task is relatively easy. Almost anyone can do the job by just learning a few electrical procedures that are simple. You also need to know some essential electrical safety measures, but aside from that, you can get on with the task fast. Installing light fixtures also requires some basic tools and a chair or ladder if you have to install the fixtures on a high surface.

Step 1 - Turn Off the Power Supply

Before beginning the project, it is important that you turn off the current first to avoid an electric shock. You can turn off the circuit breaker or remove the fuse which gives power to the area you will be working on.

Step 2 - Remove the Fixture Covers

If the fixtures you will be working on has a glass cover on, remove it first, as well as the light bulbs on the existing fixture if there is one.

Step 3 - Disconnect the Light Fixture

If there is an existing light fixture, disconnect it first from the electrical box. There should be one or more screws, which can be found on the fixture, that is used to mount it on the electrical box.

Step 4 - Remove the Mounting Brackets

If there is an old light fixture, remove its mounting brackets first before installing the new one.

Step 5 - Find Out the Existing Connections

To make a successful installation, observe how the existing fixture has been connected by wires. This step is essential since it is also the way in which you are going to install the new one. Usually, there are 2 methods that are used for connection. The wires might be connected directly with the screws that are on the light fixture, or there may be wires that come out of it which are connected to the wires that are coming from the electrical box found within the ceiling or wall.

Step 6 - Disconnect the Wires

You will have to disconnect the wires connecting the old fixture to the circuit, but you will have to memorize how it was connected to the light fixture.

Step 7 - Connect the New Fixture (Direct Connection)

Get the wires that come out from the electrical box which is mounted on the wall or ceiling and connect them with your new light fixture. There should be 3 wires, colored white, black and green. The white wire is the negative wire, and the black wire is the positive wire, while the green wire is the ground wire. A bare copper wire may also be used for the ground. If you are going to connect these wires directly to the light fixture, you should connect the black wire to the brass screw, while the white wire should be connected to the silver screw. The green ground wire should be connected with the green screw.

Step 8 - Connect the New Fixture (Wire Connection)

If the fixture you have already has wire connections, you will have to connect these with the wires coming from the electrical box. You have to use the colored wire nuts for this. These are made of plastic and should be included with the fixture package. When using this type of connection, you have to follow the same color coding for wires, i.e. black to black, white to white, and green to green.

Step 9 - Mount the Fixture

Mount the new fixture to the electrical box with the screws provided. If you are using heavy fixtures, you will have to mount it on the mounting bracket, which needs to be installed first.

Step 10 - Turn on the Power

Fix the right light bulb to the fixture you wired and switch on the power supply.

Source: Electrician/Doityourself.com

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How Ground Fault Protection Works

A "GFCI" is a ground fault circuit interrupter. A ground fault circuit interrupter is an inexpensive electrical device that, if installed in household branch circuits, could prevent over two-thirds of the approximately 300 electrocutions still occurring each year in and around the home. Installation of the device could also prevent thousands of burn and electric shock injuries each year.

The GFCI is designed to protect people from severe or fatal electric shocks. Because a GFCI detects ground faults, it can also prevent some electrical fires and reduce the severity of others by interrupting the flow of electric current.

The Problem

Have you ever experienced an electric shock? If you did, the shock probably happened because your hand or some other part of your body contacted a source of electrical current and your body provided a path for the electrical current to go to the ground, so that you received a shock.

An unintentional electric path between a source of current and a grounded surface is referred to as a "ground-fault." Ground faults occur when current is leaking somewhere, in effect, electricity is escaping to the ground. How it leaks is very important. If your body provides a path to the ground for this leakage, you could electrocuted.

Some examples of accidents that underscore this hazard include the following:

• Two children, ages five and six, were electrocuted in Texas when a plugged-in hair dryer fell into the tub in which they were bathing.
• A three-year-old Kansas girl was electrocuted when she touched a faulty countertop.

These two electrocutions occurred because the electrical current escaping from the appliance traveled through the victim to ground (in these cases, the grounded plumbing fixtures). Had a GFCI been installed, these deaths would probably have been prevented because a GFCI would have sensed the current flowing to ground and would have switched off the power before the electrocution occurred.

How the GFCI Works

In the home's wiring system, the GFCI constantly monitors electricity flowing in a circuit, to sense any loss of current. If the current flowing through the circuit differs by a small amount from that returning, the GFCI quickly switches off power to that circuit. The GFCI interrupts power faster than a blink of an eye to prevent a lethal dose of electricity. You may receive a painful shock, but you should not be electrocuted or receive a serious shock injury.

Here's how it may work in your house. Suppose a bare wire inside an appliance touches the metal case. The case is then charged with electricity. If you touch the appliance with one hand while the other hand is touching a grounded metal object, like a water faucet, you will receive a shock. If the appliance is plugged into an outlet protected by a GFCI, the power will be shut off before a fatal shock would occur.

Availability of GFCIs

Three common types of ground fault circuit interrupters are available for home use:

• Receptacle Type: This type of GFCI is used in place of the standard duplex receptacle found throughout the house It fits into the standard outlet box and protects you against "ground faults" whenever an electrical product is plugged into the outlet. Most receptacle-type GFCls can be installed so that they also protect other electrical outlets further "down stream" in the branch circuit.
• Circuit Breaker Type: In homes equipped with circuit breakers rather than fuses, a circuit breaker GFCI may be installed in a panel box to give protection to selected circuits The circuit breaker GFCI serves a dual purpose - not only will it shut off electricity in the event of a "ground-fault," but it will also trip when a short circuit or an overload occurs Protection covers the wiring and each outlet, lighting fixture, heater, etc. served by the branch circuit protected by the GFCI in the panel box.


• Portable Type: Where permanent GFCls are not practical, portable GFCls may be used One type contains the GFCI circuitry in a plastic enclosure with plug blades in the back and receptacle slots in the f rant. It can be plugged into a receptacle, then, the electrical product is plugged into the GFCI. Another type of portable GFCI is an extension cord combined with a GFCI. It adds flexibility in using receptacles that are not protected by GFCls.

Where GFCIs Should Be Considered

In homes built to comply with the National Electrical Code (the Code), GFCI protection is required for most outdoor receptacles (since 1973), bathroom receptacle circuits (since 1975), garage wall outlets (since 1978), kitchen receptacles (since 1987), and all receptacles in crawl spaces and unfinished basements (since 1990).

Owners of homes that do not have GFCls installed in all those critical areas specified in the latest version of the Code should consider having them installed. For broad protection, GFCI circuit breakers may be added in many panels of older homes to replace ordinary circuit breaker. For homes protected by fuses, you are limited to receptacle or portable-type GFCIs and these may be installed in areas of greatest exposure, such as the bathroom, kitchen, basement, garage, and outdoor circuits.

A GFCI should be used whenever operating electrically powered garden equipment (mower, hedge trimmer, edger, etc.). Consumers can obtain similar protection by using GFCIs with electric tools (drills, saws, sanders, etc.) for do-it-yourself work in and around the house.

Installing GFCIs

Circuit breaker and receptacle-type GFCIs may be installed in your home by a qualified electrician. Receptacle-type GFCIs may be installed by knowledgeable consumers familiar with electrical wiring practices who also follow the instructions accompanying the device. When in doubt about the proper procedure, contact a qualified electrician. Do not attempt to install it yourself.

The portable GFCI requires no special knowledge or equipment to install.

Testing the GFCIs

All GFCIs should be tested once a month to make sure they are working properly and are protecting you from fatal shock. GFCIs should be tested after installation to make sure they are working properly and protecting the circuit.

To test the receptacle GFCI, first plug a night light or lamp into the outlet. The light should be on Then, press the "TEST" button on the GFCI. The GFCI's "RESET" button should pop out, and the light should go out.

If the "RESET" button pops out but the light does not go out, the GFCI has been improperly wired. Contact an electrician to correct the wiring errors.

If the "RESET" button does not pop out, the GFCI is defective and should be replaced.

If the GFCI is functioning properly, and the lamp goes out, press the "RESET" button to restore power to the outlet.

Source : Electrician/Doityourself.com/Content Provided By the DOE

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How to Install Electrical Wiring

Use these tips and instructions for adding new electrical wiring. Take a few minutes to read the directions thoroughly. Following these instructions can save you time and effort and ensure a safe installation.

BASIC PRINCIPLES OF GOOD WIRING

Before beginning any electrical repair, shut off the power. Remove the fuse or trip the breaker for the circuit you will be working on in your service panel. Use a neon tester to be sure the power is off. If there is any doubt, you can remove the main fuse or trip the main breaker. Remember: Removing the main fuse or tripping the main breaker will usually shut off the power to the entire house.

Electrical wires are color coded to prevent wiring errors. White wires almost always connect to other white wires or to chrome terminal screws on switches and receptacles. Some wiring devices–such as receptacles–are back-wired by pushing the bare wire end into spring grip holes. These wiring devices are plainly labeled to show which color goes into each spring grip hole. Switches are nearly always connected into black wires in cables. The only exception is where a cable is extended, making it necessary for the white wire to play the role of the black wire. When this is necessary, the white wires should be painted black to prevent future wiring errors. Study the wiring diagram. This will help you understand the basic principles of good wiring. Also, find a good electrical how-to book. It's one book every homeowner should keep on hand for ready reference. Most home wiring is complete with either No. 14 gauge or No. 12 gauge wiring. No. 14 is the smallest wiring permitted under most codes. Always use the same size cable for a continuation of any extended wiring circuit.

CONNECT NEW WIRING TO LAST OUTLET IN CABLE

New wiring should be connected to the last outlet in a run of cable. To locate the last outlet in the run, shut off the current. Remove the cover plates from each outlet on the circuit. The last outlet in the run has wires connected to only two of the four terminal screws. The two unused terminal screws on the last receptacle serve as a starting point for wiring to a new outlet.

ATTACHING CABLE FOR NEW WIRING

Shut off the power to the circuit you will be working on at the service panel. Loosen the screws holding the receptacle in the box and remove it, as shown. Attach the the earth wire (the bare or green) to the chrome terminal. The yellow (or green in some instances) wire should be connected to the receptacle and the box maintaining the equipotential bonding on the earth system. The earth wires should only be connected to the correct screw terminals on the recepticle to the brass terminal on the receptacle and to the box, if the box is metal. Use care to match the size of the original cable. If No. 12 wire is used, continue with No. 12. If No. 14 wire is used, use No. 14 for continuing the cable. The size of the cable is usually stamped on the side of the cable. New wiring can be connected to continue the run beyond the last receptacle. Note that the new wires are pulled through knockout plugs in the back of the outlet box.

ADDING NEW WIRING FROM A JUNCTION BOX

New wiring can also be tied into a junction box, unless the wiring in the junction box is already at maximum capacity. Before tying in at a junction box, always trace the cables leading to the box to check the voltage. Be sure you are not connecting a 120-volt outlet to a run of wire providing 240 volts for larger appliances. To tie in new wiring at a junction box, first shut off the current at the service panel. Locate the main supply cable coming into the junction box from the service panel. Locate the supply wire by tracing the white wires. All white wires in the junction box will be attached to the white wire on the supply line. Knock out the unused plug on the junction box and run the new line from the box as illustrated. Be sure to use a cable clamp to secure the cable to the junction box.

TYING IN NEW WIRING AT A CEILING LIGHT

You can tie in new wiring at a ceiling light if the light is not controlled by a switch. Shut off the current at the service panel. Tie white wires to white wires and black wires to black wires, as illustrated. Connect the ground wires as illustrated. If you are using a metal box, attach them to the box as well as the light fixture. Knock out an opening in the outlet box, and continue the new wiring as illustrated.

ALWAYS MATCH CONNECTORS TO TYPE OF CABLE USED

Some boxes come with built-in connectors. Armored cable connectors have inner rims to hold fiber bushings at the end of the cable. Nonmetallic cable connectors are designed to grip the installation around the cable with a two-screw clamp. Regardless of the type of cable used, always leave about 6" to 8" of wiring in the box to allow plenty of wire for making easy connections. You can tighten the nut on either type of cable connector by placing a screwdriver in the notch and tapping the screwdriver lightly.

MAKE ALL CONNECTIONS IN APPROVED BOXES

Always remember that connections must be made in an approved box. Never connect one cable to another by an open-line splice. All switch, outlet, and junction boxes must be positioned so they are always accessible. You can easily remove knockout plugs with a nail punch, screwdriver or metal rod.

RUNNING NEW CABLE BETWEEN MULTIPLE FLOORS

Drill a hole through the floor from bottom to top, as illustrated. Be sure the hole is drilled into the recessed area behind the wall rather than in the open. Be sure to use a bit that's large enough to permit free passage of the wiring cable.

Run the cable through the newly drilled hole to the desired location for the new receptacle or switch. Bring the cable through the opening by using a weight on the end of a string and a wire with a hook on the end.

Using this same technique, you can add one outlet to another by drilling up through the floor, pulling the cable under the floor, and then running it to the desired position on the opposite wall. The same wiring can be pulled through for either receptacles or switches.

ADDING NEW WIRING FROM BOXES IN CEILING

If your home has an unfinished attic, it may be easier to add new wiring by attaching it to boxes in the ceiling. In this way, gravity works for you rather than against you. Attach the cable to the box as previously described.

Cut a hole in the wall at the desired location for the switch or receptacle, and run the cable from the box in the ceiling to the new outlet location. Bring the new cable through the wall and ceiling by cutting and drilling holes in and through the wall, the 2x4 plate, and the ceiling. A special fish tape is available for these types of jobs.

ADDING NEW WIRING ON THE SAME WALL

You can connect new cable from an existing outlet to a new outlet on the same wall by running it inside the wall. Mark the approximate location of the new outlet. Using a stud finder locate and mark the wall studs. Start one stud before the existing outlet and end one stud after the new outlet. Mark the exact location of the new box. Make it the same height as the existing box. Do not locate it over a stud. Using a drywall or keyhole saw, cut the opening for the new box. Using a utility knife and a drywall saw, cut a strip of drywall about 3" wide out of the wall, below the outlets. Start at the center of the first stud you marked and end at the center of the last stud; watch for nails as you cut. Carefully remove the drywall strip. Using a hand or circular saw, make two cuts 1" apart and 3/4" deep in each of the exposed studs. Using a hammer and a chisel, remove the wood between the two saw cuts.

Be sure the power is off to the existing outlet. Remove the cover plate and the receptacle. Remove one of the knockouts in the bottom of the box. Run the new wire behind the wall and up through the knockout in the box. Tighten the clamp and attach the wires. If the box does not have a clamp, place a wire clamp on the new cable. Tighten the screw to hold the clamp on the wire. Be sure the nut is off the wire clamp and run the wire up to the box as before. Feed the threaded end of the clamp up through the knockout, replace the nut and tighten. Replace the receptacle and the cover plate. On the new box, remove one of the knockouts in the bottom of the box. If the box you are using is a self-clamping box, insert the box into the wall and tighten. If not, insert the box into the wall, insert a Madison hanger on each side of the box, and bend the tabs over into the box to tighten. Finish running the wire from the existing box through the notches and up behind the wall into the box as before. Clamp the wire and install the receptacle as in the figure. Install the cover plate, turn on the power, and test the circuit with a neon tester. Shut off the power again to safely finish the project. Nail metal cable protectors to the exposed studs over the notches. Replace the drywall strip you removed earlier. Use the spackling compound and drywall tape to complete the installation. Cable can be pulled from an existing box on one wall to a new outlet on the opposite side of the same wall.

Attach a cable to the existing receptacle in the box as previously described. Allow ample slack in the cable to permit easy connection to the new box to be installed on the opposite wall. Bring the cable through the new opening with a wire, as illustrated in. Connect the cable to the new box, attach the desired receptacle, and mount the box to the wall with box supports if it is not near a stud.

TOOL AND MATERIAL CHECKLIST

• Two-Wire Cable
• Switches
• Screwdriver
• Extra-Long Bit
• Conduit
• Fish Tape
• Outlet Boxes
• Electrical Tape
• 1/4" Drill
• Cable Connectors
• Pigtails
• Hand or Circular Saw
• Madison Hangers
• Drywall Tape
• Cable Protector Plates
• Switch Boxes
• Side Cutter Pliers
• Wire-nuts
• Chisel
• Drywall or Keyhole Saw
• Three-Wire Cable
• Receptacles
• Brace
• Ripping Bar
• Wire
• Neon Tester
• Stud Finder
• Hammer
• Spackling Compound

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Check your state and local codes before starting any project. Follow all safety precautions. Information in this document has been furnished by the National Retail Hardware Association (NRHA) and associated contributors. Every effort has been made to ensure accuracy and safety. Neither NRHA, any contributor nor the retailer can be held responsible for damages or injuries resulting from the use of the information in this document.

Source : electrician/doityourself.com

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Battery Types Summary

The lead-acid battery is the most common type of battery in use today. There are other types of storage batteries, each having certain advantages.

• If the electrolyte is a paste, the cell is referred to as a dry cell. If the electrolyte is a solution, the cell is called a wet cell.

• The advantage of a carbon-zinc battery is that it is durable and very inexpensive to produce.

• The alkaline cell has the advantage of an extended life over that of a carbon-zinc cell of the same size.

• The nickel-cadmium battery has the advantage of being a dry cell that is a true storage battery with a reversible chemical reaction.

• The edison cell has the advantage of being a lighter and more rugged secondary cell than a lead-acid storage battery.

• The mercury cell has the advantage of maintaining a fairly constant output under varying load conditions.

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Battery Operations Summary

Once the basic theory behind the operation of batteries is understood, we can apply these concepts to better understand the way batteries are utilized.

• The output voltage of a battery connected in series is equal to the sum of the cell voltages.

• A battery that is connected in parallel has the advantage of a greater current- carrying capability.

• Secondary cells can be recharged; primary cells cannot be recharged.

• The unit for battery capacity is the ampere-hour.

• Internal resistance in a battery will decrease the battery voltage when a load is placed on the battery.

• Shelf life is a term that is used to measure the time that a battery may sit idle and not lose more than 10 percent of its charge.

• The charge of a battery may refer to one of two things: (1) the relative state of capacity of the battery, or (2) the actual act of applying current flow in the reverse direction to restore the battery to a fully-charged condition.

• Discharge refers to the act of drawing current from a battery.

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