If you are working with electrical wiring, there certain common electrical wiring mistakes that you should be familiar with. These mistakes can lead to short circuits, shocks and even fires. It is a good idea to know how to look for these electrical wiring mistakes so that you can correct them and avoid making them in the future.
According to the U.S. Fire Administration, recent statistics show that electrical fires accounted for 6.3%, (nearly 24,000), of all residential fires. One of the leading causes of these fires was wiring. Outdated wiring may not have the capacity to handle the increased number of electrical appliances in today’s average home. Although breakers should be triggered when an overload occurs, there is a possibility that there are worn connectors that no longer function. If this is the case, an electrical fire is highly probable.
Electrical Wiring Mistakes and Solutions
Although there are many fires that occur as a result of faulty wiring, you can prevent them from happening by being aware of common electrical wiring mistakes. This will help you to recognize and avoid errors that could lead to dangerous situations in your home or business. Here are some common electrical wiring mistakes and solutions:
Mistake 1-Making Connections Outside the Electrical Box
Junction boxes serve the purpose of protecting connections from accidental damage that may occur. They can also contain sparks and heat due to a loose connection or short circuit. Wires should always be connected to the electrical box to ensure that they are being protected properly.
Solution: If you see a connection that is not made in an electrical box, install a box and reconnect the wires inside it. This can be done fairly easily and there are online tutorials available to help at home do-it-yourselfers perform this task. If you don’t feel confident, you may want to hire an electrician to do the job for you.
Mistake 2-Cutting Wires Too Short
Cutting wires too short is a common electrical wiring mistake. Wires that are too short can result in poor connections. It is best to plan in advance to make sure this doesn’t happen and always count on having too much rather than too little. Wires should protrude at least three inches from the box.
Solution: Once a wire is cut, you may think there’s not much you can do to make it longer. However, there is an easy fix. You can add 6-inch extensions on to existing wires. Wire connectors that are easy to install in tight spots can be purchased in hardware stores and home improvement centers.
Mistake 3- Leaving Plastic-Unprotected Sheathed Cable
Plastic sheathed cables that are left exposed between framing members are easily damaged. In fact, the electrical code requires that cable is protected in these areas. Cable can be especially susceptible to damage if it runs under a wall or ceiling framing.
Solution: Protect the exposed cable by nailing or screwing a board that is 1 ½ thick alongside the cable. The cable does not have to be stapled to the board. If you are running the wire along a wall you can use a metal conduit for this purpose.
Mistake 4- Poor Support for Outlets and Switches
Loose switches and outlets are not only an eyesore, they’re dangerous. Connections that are not secure can move around, causing wires to loosen from terminals. After some time, these wires can arc and overheat causing a fire hazard.
Solution: You can shim under the screws to make a tight connection to the box. This can be done using spacers that can be purchased at home improvement centers or hardware stores. You can also use small washers or a coil of wire wrapped around the screw for this purpose.
Mistake 5-Installing a Three Slot Receptacle without a Ground Wire
Two slot outlets are fast becoming outdated because they are not grounded. To update to new safety regulations and accommodate modern appliances, it may be tempting to replace them with three slot receptacles. However, if you do not install a ground wire, these outlets are no safer than their two slot alternatives.
A tester can help you determine if your outlet is grounded. A series of light will let you know if the outlet is wired correctly and what faults exist if any. You can buy these items at hardware stores or home improvement outlets.
Solution: If you find that a three slot outlet is in an ungrounded box, it is best to follow reliable instructions on how to properly replace a two-slot outlet with a three slot outlet. If you don’t feel confident, it’s best to leave this work to a trained professional. In a worse case scenario, simply put the two slots outlet back where they were originally placed. This is safer than having a three-slot receptacle without a ground wire.
Mistake 6- Recessing Boxes Behind the Wall Surface
Electrical boxes should be flushed to the wall surface if the surface is made of a combustible material. If they are recessed behind walls that are made of wood, they can heat the surface which can lead to sparking and fire.
Solution: If you find an electrical box that is recessed behind the wall, it is best to install a metal or plastic box extension to solve the problem. If you are using a metal extension on a plastic box, it is a good idea to connect the metal extension to the ground wire in the box using a grounding clip and a short piece of wire.
Mistake 7- Installing Cable Without a Clamp
If a cable is not secured with a clamp, it can move around and strain connections. In metal boxes, a sharp edge can cut the insulation of the wires if they rub against it. Because of this, cables must be connected to the box with an approved cable clamp. In single plastic boxes, cable clamps are not necessary, but the cable must be stapled within 8 inches of the box. A larger box should have built-in clamps and the cable must be stapled within 12 inches of the box.
Solution: The relatively simple solution to this is to install a clamp. However, you must make sure that the sheathing on the cable is trapped under the clamp and about ¼ inch of the sheathing is visible inside the box. Some boxes have built-in cable clamps. If this is not the case, buy the clamps separately and install them along with the cable.
Mistake 8-Overfilling Electrical Boxes
As stated earlier in this article, there is an increased number of appliances and devices being used in modern households. This can make for more cables which may be stuffed in a box that cannot accommodate them. Although the National Electrical Code specifies a minimum box size to reduce the risk, it doesn’t eliminate the chances of overcrowding which can lead to short-circuiting and fire.
Solution: The solution to this electrical wiring mistake is to buy a larger box. However, this is easier said than done as many factors should be taken into consideration when trying to find the correct size box for your safety needs. You must first count all the items in the box, which include the hot and neutral wires, the ground wires, the cable clamps, and count 2 for each device (including switches and outlets but not light fixtures).
Multiply the total by 2.00 for 14 gauge wire and 2.25 for 12 gauge wire to get the minimum box size in cubic inches. Then find a box that is at least this big. A plastic box will have the volume stamped inside or on the back of it but steel boxes won’t be labeled. Therefore, you will have to measure the height, width, and depth and then multiply the three to come up with the volume.
Mistake 9- Reversing Hot and Neutral Wires
If you connect a hot wire to a neutral terminal in an outlet, it can result in an electric shock that can be potentially fatal. You may not even realize anything is wrong until a person actually gets shocked because the electrical system may function as expected despite the unknown danger.
Solution: The best way to avoid this from happening is to be familiar with the different colors of electrical wires and the function of each, as well as the proper way they should be connected. Here are some tips:
- White wires should always be connected to the neutral terminal of outlets and light fixtures.
- Neutral terminals are always marked usually by a silver or light colored screw
- Hot wires should be connected to the other terminal (not the neutral).
- A green or bare copper wire will be the ground wire.
- The ground should be connected to the green grounding screw or to a ground wire or grounded box.
Mistake 10-Wiring a GFCI Backward
GFCI outlets are protective devices that work by shutting off power when it detects differences in current that could result in shock. They have two pairs of terminals, one pair that is labeled ‘line’ for incoming power for the GFCI outlet itself. The other set is labeled ‘load’ and it provides protection for downstream outlets. If the two are mixed up, the outlet will not be effective.
Solution: Make sure you are educated on how to properly connect the outlet and switch the wiring if an error is found.
Preventing Code Violations
Wiring properly and avoiding fire hazards are not only intended to keep your entire family safe; it is necessary in order to meet the requirements of the NEC (National Electrical Code). If these codes are not followed, there could be issues with insurance or passing inspections down the road. Here are some code violations that you should be familiar with as to avoid them from happening.
Choose the Correct Circuit Breaker: Circuit breakers are protective devices, but different types will be effective in different applications. There are standard circuit breakers, ground fault circuit interrupters and arc fault interrupters. It’s a good idea to familiarize yourself with how each should be used in accordance with NEC codes.
Use Tamper Resistant Receptacles: These are installed to stop children from getting an electrical shock that may occur when they insert foreign objects into outlets. They are required in all locations as per national electric code.
Don’t Install the Wrong Cover on an Outdoor Receptacle: There are several types of covers that can be used for outdoor receptacles. To determine which one will be suitable, you have to figure out how likely the outlet is to become affected by the weather and dampness. The NEC requires that all 15 and 20 amp receptacles be rated as weather resistant and tamper resistant if they are installed in wet or damp locations.
Make Sure There Are Enough Receptacles Installed: One of the missions of the NEC is to reduce the use of extension cords as they can lead to fires and tripping hazards. The NEC mandates that a receptacle outlet needs to be within a reach of a 6 ft. appliance cord from any point along a wall line and can not be measured across a passageway.
Use Sufficient Electrical Bonding: Electrical bonding is defined as the practice of intentionally electrically connecting all exposed metallic items, not designed to carry electricity in a room or building. This is a measure that protects everyone against electric shock. It is not the same thing as grounding and must be done in addition to grounding.
There are definitely many things to think about to avoid electrical wiring mistakes. Although small problems may be easy to fix, bigger jobs should be taken care of by a trained professional. He will see to it that your wiring is done safely, efficiently and up to code. Good luck ensuring the wiring in your home is done properly so that you and your family are kept safe.
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