DIY Guide: Home Electrical Repairs

Home Renovation

Are you trying to tackle some home repairs on your own? Plumbing and electrical systems in your home may seem completely different, but they have significant similarities. Water enters your home through a pipe with pressure, and when you turn on a tap, the water flows at a certain rate in gallons per minute. Similarly, electricity enters your home through wires with voltage, and when you turn on an electrical device, the electricity flows at a certain rate in amperes or amps.

When replacing a receptacle, make sure that it matches the one you are removing. If you have a grounded type, you must purchase a receptacle that has a ground terminal screw and slots for three-prong grounded plugs.
Unlike water, electricity is meant to do work, and it is converted from energy to power, which is measured in watts. Since household electrical consumption is relatively high, the unit of measure most often used is the kilowatt, which is equal to 1,000 watts. The total amount of electrical energy you use in any period is measured in terms of kilowatt-hours (kwh).

The electric meter is the instrument that records how much electricity you use. This meter tells the power company how much electricity they need to charge you for. There are two types of electric meters in general use. One type displays a row of small dials on its face with individual indicators. Each meter dial registers the kilowatt-hours of electrical energy. For example, if you leave a 100-watt bulb burning for 10 hours, the meter will register 1 kilowatt-hour (10×100 = 1,000 watt-hours, or 1 kwh). Each dial registers a certain number of kilowatt-hours of electrical energy. From right to left on most meter faces, the far right is the one that counts individual kilowatt-hours from 1 to 10; the next one counts the electricity from 10 to 100 kilowatt-hours; the third dial counts up to 1,000; the fourth counts up to 10,000; and the dial at the extreme left counts kilowatt-hours up to 100,000. If the arrow on a dial is between two numbers, the lower number should always be read.

The article provides information about electric meters and the three main lines responsible for supplying electricity to homes. There are two types of electric meters, one with individual dials and the other with numerals in slots like an odometer. The latter is read from left to right, and some meters use a multiplying factor to calculate the true figure in kilowatt-hours. The article explains how to read your meter to verify charges on your electric bill and become a better watchdog of electrical energy consumption in your home.

The three main lines supply 110-120/220-240 volts AC to homes, providing 110-120-volt power for lighting, receptacles, and small appliances, and 220-240-volt power for air conditioning, an electric range, a clothes dryer, a water heater, and electric heating. The power company’s service equipment disconnects the service from the interior wiring system, and it’s usually a main fuse, main breaker, main disconnect, or “the main.” The article explains how the main entrance panel, also known as the main box or entrance box, handles the distribution of power throughout the building. The three wires from the meter enter this box, and the heavily insulated black and red lines are attached to the tops of parallel copper bars called buses, while the neutral wire is attached to a separate grounding bar.

The article also discusses overload protection and how circuit breakers automatically trip open to interrupt the flow of electrical current when it overloads the circuit. Power is distributed through various electrical circuits that start in the main entrance panel, and the hot lines are attached directly to the hot main buses, while the neutral wire is always connected to the ground bus and should never pass through a fuse or circuit breaker.

In your electrical system, fuses and circuit breakers act as safety devices. Without them, operating too many appliances on a single circuit could cause the cable carrying the power for that circuit to get extremely hot, short circuit, and possibly start a fire. To prevent this, circuit breakers and fuses are designed to trip or blow, stopping the flow of current to the overloaded cable. For example, a 15-ampere circuit breaker should trip when the current through it exceeds 15 amperes. A fuse that blows or a circuit breaker that trips is not faulty; it is doing its job properly, indicating that there is trouble somewhere in the circuit. A blown fuse or tripped circuit breaker usually means there are too many appliances plugged in to that circuit or some malfunctioning device, like an appliance with an internal short, is connected to the circuit. Before replacing a blown fuse or resetting a tripped circuit breaker, locate and eliminate the cause of the trouble.

It is crucial never to try to defeat this built-in safety system by replacing a fuse with one of a higher current-carrying capacity. The fuse or circuit breaker capacity should be equal to or less than the current-carrying capacity of the conductors. Circuit breakers do not blow like fuses; they are switches that automatically trip open to interrupt the flow of electrical current when it overloads the circuit. To reset a tripped breaker, turn it fully off and then back on.

Circuits to all the devices in your home that require electrical power start from the fuses or circuit breakers. There are two types of circuits: feeder and branch. Feeder circuits use thicker cables that travel from the main entrance panel to smaller distribution panels called subpanels, or load centers. These auxiliary panels are located in remote parts of a house or in outbuildings and are used for redistribution of power, such as in a garage. Branch circuits run from either the main entrance panel or from other smaller panels to the various points of use in your home. For 110-120-volt needs, a circuit branches out through a circuit breaker from one of the main buses and from the ground bus. For 220-240 volts, many circuits use only the two main buses. But all three wires are needed for devices that operate on both 110-120 volts and 220-240 volts. The 110-120-volt branch circuits go through fuses or breakers, which are labeled either 15 or 20 amps. The 15-amp branches go to ceiling lamps and wall receptacles in rooms where less energy-demanding devices, such as table lamps, are found. The larger 20-amp circuits go to receptacles in the kitchen, dining, and laundry areas where heavy-duty appliances are used.

A 15-amp circuit has a capacity of 1,800 watts, and a 20-amp circuit has a capacity of 2,400 watts, but it is recommended to limit the load on a 15-amp circuit to 1,440 watts and a 20-amp circuit to 1,920 watts. To determine the load on a circuit, add up the wattages of all devices and lamps connected to it. Take into account motor-driven appliances that draw more current when starting up. For example, a refrigerator may draw up to 15 amps initially but will settle down to around 4 amps. If the total current load exceeds the capacity of the circuit, the fuse will blow or the circuit breaker will trip.

It is important to practice proper safety measures when working with your home’s electricity. While some repairs require a licensed electrician, many can be done by a do-it-yourselfer. Regularly inspect wiring and replace cords with damaged insulation. To work safely with electricity, never break the conductor’s insulation, turn off the power before doing any work on a circuit, and prevent others from accidentally turning the power back on while you are working.

Electrical Safety Tips

Some home electrical repairs require a licensed electrician, but the repair or replacement of many electrical components can be done by a do-it-yourselfer. Make safety your first priority, and you’ll be amazed at what you can do to maintain and upgrade the electrical devices in your home.

All electrical devices and electrical wires are designed to provide the greatest measure of electrical safety, but you can defeat any built-in safeguards with carelessness and ignorance. To work safely with electricity, be aware of the following hazards and precautions:

• Never do anything that would break the conductor’s insulation. Do not, for example, staple an extension cord to a baseboard or wall. The staple can cut through the insulation and create a short circuit, which, in turn, can start a fire. Moreover, you should examine all wiring regularly and discard any cord with brittle insulation. Replace the old cord with a new one that has good insulation.

• Turn the power off before replacing a receptacle or a switch or doing any other work on a circuit. If your system operates with fuses, remove the fuse for the circuit you’re working on and slip it into your pocket or toolbox. If you leave it nearby, someone might put the fuse back in while you’re working on the circuit. If your home’s electrical system uses circuit breakers, trip the appropriate circuit breaker to its OFF position. Then, to make sure no one accidentally flips the circuit breaker back on while you’re working, put a piece of tape and a sign over the circuit breaker’s handle telling people what you’re doing.

• When working on an electrical circuit, it is important to join wires and connections inside a designated electrical box. Solderless connectors are the best option, either in the form of crimp-on or screw-on wirenuts. It is crucial to never connect wires in inaccessible areas such as behind a wall or ceiling without a designated box. When connecting insulated wires, ensure that no bare wire is exposed beyond the connection, and the insulation reaches the solderless connector or terminal screw.

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  One of the most effective ways of joining wires is through the use of solderless connectors called wirenuts. Twist the conductor ends together and screw the wirenut into the twisted ends, ensuring no bare conductor is exposed.

  All members of the household must know how and where to turn off the master switch to cut off all electrical power.

• Do not wade in water if there is a chance of contact between water and electricity until the master switch is shut off.

• Always assume that an electrical receptacle or apparatus is energized until proven otherwise through a circuit tester or by pulling a fuse or tripping the disconnect plug.

• When working with electricity, use only insulated pliers.

• While working with a fuse box or circuit breaker box, stand on a wooden platform or dry board. Use a wooden stepladder instead of an aluminum one to minimize the risk of shock when working with electrical wiring.

• You can save time by identifying which electrical circuits activate each receptacle in your home and then creating a diagram or printing the information inside the circuit breaker or fuse box.

Electrical Grounding

Proper grounding of your electrical system is crucial to your safety. Electricity follows the path of least resistance, which could be you if an electrical component or appliance is not grounded.

Grounding directs electrical energy into the earth by providing a conductor that has less resistance than you. This is done by attaching one end of a wire to an appliance’s frame and fastening the other end to a coldwater pipe. Most electrical cable with plastic coating contains a bare wire that carries the grounded connection to every electrical box, receptacle, and appliance in your home. You can verify whether your electrical system is grounded by checking the receptacles. If you have receptacles that accept plugs with two blades and one prong, your system should have three wires, one of which is a grounding wire. The prong carries the safety ground to the metal frame of any appliance that has a three-wire plug and cord.

An appliance’s metal frame can pose a safety hazard to you and your family. If the insulation of a power cord wears away just where the cord enters the metal frame, contact between the metal current conductor and the metal frame could make the entire appliance electrical. Touching a charged metal frame of the appliance while touching a water faucet or radiator can make the current surge through you.

It is important to inspect and maintain the electrical system to avoid potential safety hazards caused by conductor/metal contact. Check the entry points of wires into metal pipes, lamps or electrical boxes to ensure that the surface is free of burrs that could damage the wire and its insulation. Washers and grommets can protect the wire at these entry points, but the best way to ensure safety is to ground the entire system and ensure that the ground circuit is electrically continuous. Safety should always be a top priority when performing home repairs, and it is advisable to seek the help of a professional electrician when needed.

When a circuit trips, it is important to have a list of all the branch circuits in your home to identify which receptacles and fixtures are on each branch circuit. You can remove a fuse or trip a circuit breaker to see which equipment or devices are de-energized. Once you have identified the receptacles, fixtures, and appliances on each circuit, write this information on a card and attach it inside the main entrance panel. If a circuit goes off, check for visual or audible indication of the problem, disconnect the faulty equipment and inspect the fixtures for signs of malfunction. If the circuit holds, the problem may be too much current draw for the circuit to handle, so remove some of the load from the circuit.

In case a new fuse blows or the circuit breaker does not reset, the issue may be with the connected equipment or the circuit cable itself. Check all the connected items and examine them for faults until the offending equipment is identified. If the circuit still goes out with no loads connected, there may be a fault in the wiring, probably due to a short in a junction or receptacle box, or in the cable itself. If you suspect faulty electrical wiring, call an electrician.

Although circuit breakers are usually trouble-free, they may fail occasionally. This results in the circuit not energizing, even when there is no fault. If the circuit breaker has a burnt plastic smell, a loose and wobbly trip handle, or rattles when moved, it has probably failed. Turn off the circuit, check the breaker with a continuity tester, and replace it if necessary.

Coping With a Power Outage

If the power goes off in the entire house, it may be due to a general power outage or a problem in the residential wiring system. To begin with, check whether the outage is a general power outage or restricted to your home. Look around the neighborhood to see if everyone else’s lights are off if it’s nighttime, or call a neighbor during the day to see if others are affected. If you have a circuit breaker main disconnect, check whether it has tripped to the OFF position. If the main entrance is wired with fuses, pull out the fuse block and check the fuses with a continuity tester to see if they are still good.

If the trouble is a general power outage, call the power company. If your main breaker is still in the ON position or both main fuses are good but your neighbors have power and you don’t, the fault lies between your main entrance panel and the power transmission lines. Call the power company, as this part is their responsibility. If you find a tripped main breaker or blown main fuses in your main entrance panel, the problem lies within the house and may be serious. Do not attempt to reset the breaker or replace the fuses. It may be a system overload, using more current than the main breaker can pass, or a dead short somewhere in the house.

The first step is to go through the house and turn off everything possible. If you have a circuit breaker panel, flip all the breakers to the OFF position. Reset the main breaker to the ON position and then trip the branch circuit breakers back on one by one. If one of them fails to reset, or if the main breaker trips off again as you trip the branch breaker on, the source of the trouble lies in that circuit. The circuit needs to be cleared of the fault.

If all of the breakers turn back on and the main breaker remains on, there are two possible scenarios. First, something that was disconnected earlier may be faulty, so inspect each item along the line for possible faults and plug them back in one at a time. Eventually, you will discover which item is causing the problem, either by visually noticing or by seeing a breaker trip off when it is reconnected. Alternatively, the problem may be systemwide overloading, which is characterized by the main breaker repeatedly tripping out when everything in the house is running, yet no electrical faults can be found. To solve this problem, you can either reduce the total electrical load or have a licensed electrician install a new larger main entrance panel with new branch circuits to serve areas of heavy electrical usage and help share the total load.

If the main panel has fuses, the troubleshooting approach is similar, but you will need a supply of fuses on hand. Start by pulling all the cartridge fuses and unscrewing all the plug fuses in the panel. Replace the main fuses and put the fuse block back into place. Then, one by one, replace each fuse or set of fuses until the one that’s causing the outage blows out again. This is the circuit that must be cleared. General overloading, however, will cause the main fuses to go out again, in which case you should call in an electrician to test for overloading and suggest remedies.

To prepare for power outages, assemble an emergency blackout kit that includes candles or oil lamps and matches for area lighting, a flashlight or battery lantern for troubleshooting, a circuit tester, a tool kit for making electrical repairs, and various replacement parts and lightbulbs. With a little preparation and knowledge, you can handle your next power outage without being left in the dark.

Restoring a Circuit: A Guide

Older residential wiring systems in homes use a two-wire system for the 110-120-volt branch circuits. One of the wires is hot, while the other is neutral. In some cases, the neutral can also function as a ground, but this is not always the case. If it is not, the system is ungrounded and can be dangerous. To determine whether your circuits are ungrounded, check the receptacles. Ungrounded receptacles only have two openings for each plug. Modern wiring requires three conductors, which means that receptacles have three openings: two vertical slots and one rounded hole centered above or below them.

©2006 Publications International, Ltd. A plug-in polarity checker can enable you to make sure your outlets are installed properly.

While both two-pronged and three-pronged plugs can be used with these receptacles, only the three-pronged ones have an equipment grounding line for electrical equipment. Additionally, one of the vertical slots is smaller than the other, so newer two-pronged plugs can only be inserted in one direction. This ensures that the equipment is properly polarized, with hot sides connected to hot sides and neutral sides connected to neutral sides.

For safety and proper operation, ensure that all receptacles on each circuit are connected with the correct conductors and that there are no polarity reversals along the line. Unfortunately, even professional electricians may not connect receptacles correctly. You can use an inexpensive tester called a polarity checker to test your receptacles. The tester looks like a three-pronged plug and has three neon bulb indicators. Plug it into a receptacle to check its polarity. The lights will indicate whether the polarity is correct and, if not, which lines are reversed. If there is a reversal, turn off the circuit, remove the receptacle from the electrical box, and switch the wires to the proper terminals. If the equipment-grounding circuit is not working, use a continuity tester to trace the circuit until you find the disconnection or missing link. Reconnect it to restore the circuit’s effectiveness.

Replacing an Electrical Receptacle: A Step-by-Step Guide

Tools You’ll Need Here are the tools you will need when replacing an electrical receptacle: Replacement receptacle Screwdriver Single-edge razor blade or utility knife Grounding screws or clips Wire stripper with cutting blade

Almost everyone has dealt with an electrical receptacle that doesn’t work properly or at all. How does this happen? There are two possible explanations.

Improper use can lead to permanent damage of an electrical receptacle. Even something as simple as sticking a hairpin or paper clip into it can cause damage and shorten the life of the receptacle. Plugging in an appliance with a short circuit can also cause the same damage. If the receptacle is damaged, it must be replaced.

Another reason for an electrical receptacle to not work efficiently and safely is due to age and overuse. Signs of a worn-out electrical receptacle include the weight of the cord pulling the plug out or the plug blades not making constant electrical contact within the slots. In this case, the old receptacle should be replaced.

To replace an electrical receptacle, follow these steps: deenergize the circuit, inspect the old receptacle, remove the plate covering the receptacle, remove the screws holding the receptacle in the electrical box, disconnect the wires, and connect the wires to the new receptacle. Make sure the replacement receptacle matches the old one and is of the same type. Connect the wires in a clockwise direction and ensure all uninsulated wire is secured safely under the screw heads. Finally, push the receptacle back into the box and replace the cover plate.

The slots in certain electrical outlets are not the same size. One slot is wider than the other and should be used for the white or neutral wire, while the narrower slot should be used for the black or hot wire. Some plugs are designed with one wide and one narrow blade to fit into the outlet properly. This is called a polarized plug and ensures the hot and neutral wires remain correctly identified from the circuit to the appliance. If you want to learn more about electrical work, check out the related HowStuffWorks articles which cover topics like replacing a wall switch, rewiring a lamp, installing a fluorescent light, repairing a doorbell, and installing a ceiling fan.

FAQ

1. What are some common electrical repairs that can be done at home?

There are a few common electrical repairs that homeowners can tackle. One is replacing a light switch or outlet. Another is fixing a tripped circuit breaker. You can also replace a light fixture or ceiling fan. However, it’s important to remember that more complex repairs, such as rewiring a room, should be left to a licensed electrician.

2. What tools do I need for home electrical repairs?

For basic electrical repairs, you’ll need a few tools such as wire cutters, wire strippers, pliers, and a voltage tester. You may also need a screwdriver or drill, depending on the repair. It’s important to have a basic understanding of how to use these tools safely before attempting any electrical repairs.

3. How do I safely turn off the power before making a repair?

Before starting any electrical repair, you should always turn off the power to the circuit you’ll be working on. To do this, locate your electrical panel and flip the switch that corresponds to the circuit you’ll be working on. You can also turn off the main circuit breaker to shut off power to the entire house. Always double check that the power is off with a voltage tester before starting the repair.

4. What should I do if I encounter a problem I can’t fix?

If you encounter a problem you can’t fix, it’s important to call a licensed electrician. Attempting to fix a problem you don’t fully understand could be dangerous and result in further damage to your electrical system. A licensed electrician will have the knowledge and experience to safely diagnose and repair any electrical issue.

5. Can I replace a circuit breaker myself?

Replacing a circuit breaker should be left to a licensed electrician. Circuit breakers have live electrical connections that can be dangerous if not handled properly. A licensed electrician will have the knowledge and tools to safely replace a faulty circuit breaker.

6. How do I know if I need to replace an electrical outlet?

If your electrical outlet is loose, cracked, or discolored, it may need to be replaced. You should also replace an outlet if it feels hot to the touch or if it frequently trips the circuit breaker. If you’re unsure if your outlet needs to be replaced, it’s best to call a licensed electrician for an inspection.

7. What should I do if I see sparks when I plug something in?

If you see sparks when you plug something in, immediately unplug the device and turn off the power to the circuit. This could be a sign of a loose or damaged wire, which can be dangerous and cause an electrical fire. Call a licensed electrician to inspect the outlet and make any necessary repairs.

8. Can I install a ceiling fan myself?

Installing a ceiling fan can be a DIY project, but it’s important to follow the manufacturer’s instructions carefully. You’ll need to turn off the power to the circuit, assemble the fan, and attach it securely to the ceiling. If you’re unsure about any part of the process, it’s best to call a licensed electrician for assistance.