Plenty of home improvement and remodeling projects require either new wiring or replacements for old, worn, or fried connections. For extensive work, it is obviously best to hire an electrician, but some projects might be within the skill level of the average DIYer. Read this article for advice before taking on your next wiring job.
Basics of Wiring
When working with wiring, always cut the power supply at the breaker box first before beginning any actual work. Then, test the local area with a neon tester to make sure that the power is off and that it is safe to go ahead.
Most wiring in a home is either 12-gauge or 14-gauge. Typically, when attaching existing wiring to a device or fixture, you will follow the color code by matching each color wire with its corresponding twin. Light switches, for example, operate on the black wire and will connect directly to another black wire already in the system.
Electrical wiring in the US follows the same basic color codes: red and black wires denote live wires, white wires serve as the ground, and blue, yellow, or other colors are used for switches or other specific purposes.
Connect to the Outlet
Usually, the wiring which you are installing will be affixed to the final outlet in the current run of cable. This can be determined by finding the outlet with wires connected only to two of the four terminal screws. Make sure the current is shut off to the circuit and then remove the faceplates to each outlet to find the one you’re looking for.
Attaching Cable for New Wiring
Loosen the screws holding the receptacle in place and remove it in order to add wiring. Take care to make sure you attach the correct size of cable. If 12-gauge is being used, continue with 12-gauge cable; the same applies to 14-gauge. White wire will be attached to the chrome terminal on the receptacle while black wire will be attached to the brass one. The ground wire will be attached to the box itself, but only if it is made of metal.
Adding New Wiring From a Junction Box
New wiring can also be tied into a junction box, so long as there is excess capacity. Once the power is shut off, carefully trace the cables connecting to the box to be sure you’re not connecting a 240v supply to a 120v outlet, or vice versa.
To tie in the new wiring, first locate the main supply wire by tracing the white wires, as all of these will be attached to the white wire on the supply line. Take out the unused plug and run the new wiring from the box. Clamp the cable to secure it to the junction box.
Tying in New Wiring at a Ceiling Light
If your light fixture isn't controlled by a switch, you can tie new wiring in order to add it. Make sure the power supply is shut off and then connect the wires according to the color code: white to white and black to black. Connect the ground wires together and attach them to the metal box and the light.
Always Match Connectors to Type of Cable Used
Depending upon the type of box you have purchased, it may or may not come with built-in connectors. There are two main types of cable connectors you will have to differentiate between when making a new connection. Armored types have inner rims to hold fiber bushings at the end of the cable, and nonmetallic kinds have a two-screw clamp that will fasten the installation around the cable. You must always leave at least six inches of wiring inside the box so that you have enough slack to make a connection.
Make All Connections in Approved Boxes
Use only boxes that are approved for your electrical application and never use an open-line splice when adding wiring. Properly position all boxes so that they’re always accessible.
Running New Cable Between Multiple Floors
Drill a hole wide enough to accommodate the hardware from top to bottom through the floor in a recessed area behind the wall. Then thread a cable through the newly drilled hole using a wire with a hooked end and a string with a weight attached, as is shown in the diagram to the right.
Adding New Wiring From Ceiling Boxes
Homes with attics may be more easily wired by using ceiling boxes. This method uses gravity to make the job of adding wiring easier. Start by attaching your cable to the box as previously described. Then, saw a hole at the desired position and install the cable box. Run new cable by adding more holes in places such as the 2x4 board plate and ceiling material.
Adding New Wiring on the Same Wall
Cable can be run between existing and newly installed outlets by running it through the wall. Find the spot (not on a stud) for the new outlet and mark an approximate location. Then, using a stud finder, locate and mark the studs in the wall. Start your marks with the wall stud before the existing outlet and finish with the stud on the opposite side of the new outlet location, as shown.
Now it’s time to mark the exact dimensions of your new outlet. Make sure that it is level with the old one before you use a keyhole or drywall saw to cut the opening in the wall.
With the same drywall saw, cut a three inch strip of drywall starting at the middle of your first marked stud and ending in the center of the last. Switch to a hand or circular saw and made two cuts, about an inch apart and 3/4-inch deep in the exposed studs. Take a hammer and chisel to the wood between the cuts to remove it.
Once you have tested the existing outlet to guarantee that the power is off, take off the cover of the existing outlet box. Add a wire through a knockout, threaded end first, and tighten the clamp if there is one. If there’s not, place a new wire clamp on the cable and tighten the screw to hold it in place. Take the nut off the clamp to feed it through the knockout in the box, then replace the nut and tighten. Attach the wires once the cable is secure and then screw the receptacle back in and put the face plate back on.
Move to the new box and take away one of its knockouts. Self-clamping boxes need only be installed and tightened. Otherwise, use a Madison hanger on each side. Run the wire from the existing outlet behind the wall, using the notches, and up into the new box. Clamp the wire and replace the receptacle into the wall.
Finish reassembling all of the hardware before turning the power back on and testing the current to be sure the wiring is working properly. If everything checks out, it’s time to clean up. Attach cable protectors over the notches in the wall and put the strip of drywall you cut earlier back into place, repairing the damage with spackling and drywall tape.
Tuesday, July 24, 2018
Tuesday, July 17, 2018
Common Electrical Mistakes Made by Homeowners
Common Electrical Mistakes Made by Homeowners
Electrical wiring can be easy enough for the average homeowner, but there are some common mistakes that happen far too often. These may seem innocent enough at the time, or they may go completely unnoticed, but their consequences can be severe: A simple pinched wire or loose connection can lead to a fire that burns your house down. So work carefully and always follow the local electrical code rules. If you make a mistake or damage some wiring in any way, stop and fix the problem before finishing the rest of the project. Common electrical mistakes are disasters waiting to happen.
1. Improperly Installed Wire Staples
When installing NM (Romex) electrical cable, you typically must secure it to the wall, ceiling, or floor framing with cable staples. These are easy to install but just as easy to get wrong. Amateur electricians commonly hammer the staples too tightly, which can pinch the wires inside the cable, possibly damaging the insulation or creating a point of electrical resistance, which can make the wires hot.
A pinched wire is particularly dangerous because if the metal staple cuts through the insulation, it can lead to an arc fault, a very common cause of electrical fires.
2. Box Installation Mistakes
Nailing an electrical box to wall or ceiling framing seems simple enough, but often they are installed too deep for the drywall or other finish material. If you’re installing 1/2-inch drywall on a wall in a living room, for example, the face of the box should extend 1/2 inch out from the face of the wall stud. This ensures that the face of the box will be flush with the drywall when it is installed.
If a box is mounted too deeply and there is more than 1/4 inch between the box's front edges and the face of the wall finish, install a box extension ring to bring the box flush with the wall surface.
3. Improper Wire Sizing
Electrical wiring size relates to how much amperage (amps), or electrical current, it can safely handle. For example, 14 AWG (gauge) wire is rated for a maximum of 15 amps; 12 AWG is rated for 20 amps. If you're tapping into a circuit that has a 20-amp breaker, you must use 12 AWG electrical cable. If you use 14 AWG wiring on that circuit, the wiring won't be adequately protected by the 20-amp circuit breaker, and the wires could overheat and cause a fire without the circuit breaker tripping.
4. Over-Fusing a Circuit
Over-fusing is a common mistake that happens in older houses with fuse boxes (rather than breaker boxes). With older-style fuses, the screw-in fuses all have the same size of base, and it's possible to replace a 15-amp fuse with a 20-amp fuse, even though the circuit wiring is rated for a maximum of only 15 amps. If there's a problem in the circuit, such as a short or arc fault, the fuse may not blow before the wiring overheats, which can cause a fire.
All fuse boxes today should use Type S, or "tamper-proof," fuses that have a specific base size for each amperage rating, preventing over-fusing.
5. High-Wattage Light Bulbs
Everyone has been guilty of this at one time or another. Most light fixture in a home have a maximum rating for light bulb wattage, and 60-watt is the most common. The maximum wattage is usually posted next to the socket for safety purposes. If you ignore the notice and use a bulb with higher wattage than the maximum rating—for example, using a 100-watt bulb in a 60-watt fixture—the bulb can melt the wiring insulation in the fixture, creating a potential shock and fire hazards.
The solution is simple: Don't exceed the wattage maximum or, better yet, use LED bulbs instead of incandescent. LEDs have much lower wattage ratings (by a factor of seven) with the same amount of light output.
6. Short Wires in a Box
When making a connection in a junction box, the length of wire in a box is important. The general rule of thumb is to install 6 inches of wire in a box in order to have enough to make proper connections. You need enough wire to strip and connect the wires to use the wires in the future, if necessary. Once connected wires are folded neatly into the box.
On the other hand, having too much wire in a box can be just as bad as too little. In this case, when you try to jam too much wire in the box and also install devices in the same box, there is always the chance that the wires could get damaged and short out.
7. Loose Wire Connections
Connections of wires should be made with wire connectors. Wires should not simply be twisted together and wrapped with electrical tape, as this connection can easily come loose.
Loose connections on switches and outlets pose another problem. When tightening a wire around a terminal screw on a device, bend the stripped wire into a semicircular loop and put the open end of the loop towards the right. Tighten the screw in a clockwise motion until tight. This will draw the bare metal end of the wire around the screw, thus closing the loop tighter. If you have the open end the other way, the loop will actually open up a bit, causing the connection to not be as secure.
8. Connecting Wires to the Wrong Terminals
Connecting a wire to the wrong terminal on an outlet, appliance, or other electrical device can cause several potential problems and can be very dangerous.
When wiring an outlet, for example, the hot wire of a circuit connects to the brass-colored screw terminal; this is connected to the short straight slot on the face of the outlet. The neutral wire connects to the silver-colored terminal, which connects to the longer straight slot of the outlet.
The ground wire is simple. It connects to the green screw on the outlet, which cannot be mistaken for the other two. The ground connection is made through the D-shaped slot on the outlet.
9. Overloading Circuits
Whether it's too many holiday lights or a pile of wires for the entertainment center. You get one of those handy multi-outlet power strips and plug in every cord you can fit into the strip. But the strip plugs into one outlet, which is on single circuit that can only handle only 15 amps, and you're trying to pull 18 amps from it. If you're lucky, the breaker keeps tripping until you get the message. If not, you can overheat the circuit wiring and potentially cause a house fire.
Electrical wiring can be easy enough for the average homeowner, but there are some common mistakes that happen far too often. These may seem innocent enough at the time, or they may go completely unnoticed, but their consequences can be severe: A simple pinched wire or loose connection can lead to a fire that burns your house down. So work carefully and always follow the local electrical code rules. If you make a mistake or damage some wiring in any way, stop and fix the problem before finishing the rest of the project. Common electrical mistakes are disasters waiting to happen.
1. Improperly Installed Wire Staples
When installing NM (Romex) electrical cable, you typically must secure it to the wall, ceiling, or floor framing with cable staples. These are easy to install but just as easy to get wrong. Amateur electricians commonly hammer the staples too tightly, which can pinch the wires inside the cable, possibly damaging the insulation or creating a point of electrical resistance, which can make the wires hot.
A pinched wire is particularly dangerous because if the metal staple cuts through the insulation, it can lead to an arc fault, a very common cause of electrical fires.
2. Box Installation Mistakes
Nailing an electrical box to wall or ceiling framing seems simple enough, but often they are installed too deep for the drywall or other finish material. If you’re installing 1/2-inch drywall on a wall in a living room, for example, the face of the box should extend 1/2 inch out from the face of the wall stud. This ensures that the face of the box will be flush with the drywall when it is installed.
If a box is mounted too deeply and there is more than 1/4 inch between the box's front edges and the face of the wall finish, install a box extension ring to bring the box flush with the wall surface.
3. Improper Wire Sizing
Electrical wiring size relates to how much amperage (amps), or electrical current, it can safely handle. For example, 14 AWG (gauge) wire is rated for a maximum of 15 amps; 12 AWG is rated for 20 amps. If you're tapping into a circuit that has a 20-amp breaker, you must use 12 AWG electrical cable. If you use 14 AWG wiring on that circuit, the wiring won't be adequately protected by the 20-amp circuit breaker, and the wires could overheat and cause a fire without the circuit breaker tripping.
4. Over-Fusing a Circuit
Over-fusing is a common mistake that happens in older houses with fuse boxes (rather than breaker boxes). With older-style fuses, the screw-in fuses all have the same size of base, and it's possible to replace a 15-amp fuse with a 20-amp fuse, even though the circuit wiring is rated for a maximum of only 15 amps. If there's a problem in the circuit, such as a short or arc fault, the fuse may not blow before the wiring overheats, which can cause a fire.
All fuse boxes today should use Type S, or "tamper-proof," fuses that have a specific base size for each amperage rating, preventing over-fusing.
5. High-Wattage Light Bulbs
Everyone has been guilty of this at one time or another. Most light fixture in a home have a maximum rating for light bulb wattage, and 60-watt is the most common. The maximum wattage is usually posted next to the socket for safety purposes. If you ignore the notice and use a bulb with higher wattage than the maximum rating—for example, using a 100-watt bulb in a 60-watt fixture—the bulb can melt the wiring insulation in the fixture, creating a potential shock and fire hazards.
The solution is simple: Don't exceed the wattage maximum or, better yet, use LED bulbs instead of incandescent. LEDs have much lower wattage ratings (by a factor of seven) with the same amount of light output.
6. Short Wires in a Box
When making a connection in a junction box, the length of wire in a box is important. The general rule of thumb is to install 6 inches of wire in a box in order to have enough to make proper connections. You need enough wire to strip and connect the wires to use the wires in the future, if necessary. Once connected wires are folded neatly into the box.
On the other hand, having too much wire in a box can be just as bad as too little. In this case, when you try to jam too much wire in the box and also install devices in the same box, there is always the chance that the wires could get damaged and short out.
7. Loose Wire Connections
Connections of wires should be made with wire connectors. Wires should not simply be twisted together and wrapped with electrical tape, as this connection can easily come loose.
Loose connections on switches and outlets pose another problem. When tightening a wire around a terminal screw on a device, bend the stripped wire into a semicircular loop and put the open end of the loop towards the right. Tighten the screw in a clockwise motion until tight. This will draw the bare metal end of the wire around the screw, thus closing the loop tighter. If you have the open end the other way, the loop will actually open up a bit, causing the connection to not be as secure.
8. Connecting Wires to the Wrong Terminals
Connecting a wire to the wrong terminal on an outlet, appliance, or other electrical device can cause several potential problems and can be very dangerous.
When wiring an outlet, for example, the hot wire of a circuit connects to the brass-colored screw terminal; this is connected to the short straight slot on the face of the outlet. The neutral wire connects to the silver-colored terminal, which connects to the longer straight slot of the outlet.
The ground wire is simple. It connects to the green screw on the outlet, which cannot be mistaken for the other two. The ground connection is made through the D-shaped slot on the outlet.
9. Overloading Circuits
Whether it's too many holiday lights or a pile of wires for the entertainment center. You get one of those handy multi-outlet power strips and plug in every cord you can fit into the strip. But the strip plugs into one outlet, which is on single circuit that can only handle only 15 amps, and you're trying to pull 18 amps from it. If you're lucky, the breaker keeps tripping until you get the message. If not, you can overheat the circuit wiring and potentially cause a house fire.
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