DIY Frequently Asked Questions

Electrical FAQ's

Is there a special receptacle I should install outside?

Yes, we have a special box with a cover designed to protect. In addition, the receptacle should also have ground-fault circuit-interrupt protection.

Do you have a light switch that I can use to replace one in my house?

Yes, but is it a single pole or is it a three-way switch. A three-way switch is one that is used when a light is controlled by more than one switch.

What type of switches will I need to turn a light on from two different locations?

You will need a three-way switch at each location. A three-way switch will have three terminal screws on it–two brass colored screws and one that is black (or dark in color).

How do I wire a lamp switch?

With lamp wiring, there is a ribbed side and a smooth side. Unscrew the light switch. Strip and twist your wire. The ribbed side will go to the brass side of the light terminal. The smooth side will go to the silver side. Wrap around the terminals and tighten it down.

What type of switches will I need to turn a light on from three different locations?

Two of the locations will use a three-way switch and the other location will need a four-way switch.

How do I connect a wire to the terminal on my light switch?

Bend a stripped wire 180 degrees by bending it over the tip of needle nose pliers. Wrap the wire clockwise around the screw so that it will stay in place as you tighten the screw. Don’t over tighten and make sure there is no insulation under the terminal.

I’ve noticed that some outlets have a T-shaped neutral slot. What does this do?

It identifies the outlet as a 20-amp grounded receptacle and it should be used only on 20 amp circuits.

What is a transformer?

It’s a device that changes the voltage. In most home usage, it reduces the voltage for use on low-voltage equipment, such as thermostats, doorbells and low-voltage outdoor lighting.

What tool should I use to strip the plastic sheathing off wire?

A combination wire stripper tool has openings that fit different sizes of wire. When a wire is put into the correct one and pulled it will remove the covering without damaging the wire.

Is there a tool for removing the outer sheathing on cables such as Romex?

A utility knife will work, but an inexpensive a cable ripper is designed for the task and will not damage the wires inside.

I need to run some wire through my wall. Do you have any suggestions?

Instead of trying to feed the wire through, use a fish tape. This tool is a small wire on a real that is easier to feed through. Once you have fed it through the wall, attach the wire and pull the tape back through.

I think there is a short in a wire running to one of my rooms. Is there some way to test it to find out?

A continuity tester will let you know if there is a short. It is a tool that includes a battery so that it can supply a low-voltage current to devices and wires to see if there is a complete circuit.

If there is a short in the line, where should I look for it?

Search for loose taped wire; also look for worn fabric insulation on old wires and check any terminals have multiple wires since one of the wires may have slipped off.

How do I test a switch to see if it is working?

Use a continuity tester. First, shut of the electricity going to the switch and remove it. Touch the tester leads to both of the switch’s terminals. If the switch is working properly, the tester will light up when the switch is on and go out when the switch is turned off.

What is the easiest way to test an outlet?

Use a receptacle analyzer. Leave the power on, but make sure nothing is plugged into any outlet on the circuit, and turn off all switches on the circuit. Now, plug the analyzer into the outlet.  A series of lights will tell you if the outlet is wired correctly and working.

Which color of wire nut do I need?

Check the package, it will tell you what size and how many wires each color of nut will hold.

How do I use a wire nut?

Strip off about ½ inch of insulation from the wires you want to connect. Hold these wires next to each other and twist clockwise. Screw on the wire connector using only your hand strength. Make sure not bare wire is exposed.

Do you have something I can use to insulate and repair cords and wire with?

You can use heat-shrink tubing. It’s designed to fit something half its size in diameter.

Do I need special tape for wiring?

Yes, you should use electrical tape.

What does gauge mean?

Wires have size numbers that express their diameter. These are even numbers from 0 to 18, and smaller numbers indicate larger diameters that can carry more power.

I am putting a couple of more outlets in my garage can I use 14-guage wire?

While 14-guage wire is the minimum for most houses wiring, it can only be used for 15-amp circuits. Number 12-gauge wire is recommended for general home use. There is often a chart on boxes of wire that will show you recommend gauges for specific applications.

How is UF electric wire different from regular Romax cable?

If you lay cable underground, it must be UF (underground feed) cable, which has each individual wire insulated and has plastic wound around the insulated wire for weather and sunlight protection. Romax has a paper product around the wires.

What are voltage testers?

It’s an inexpensive tool that tests for live current. It can save your life. To use a voltage tester, simply plug its leads into a receptacle, or, if the cover plate is off, touch them to the screw terminals of the device. If current is present, the tester will light.

What type of wire should I use for a 220-volt outlet?

The best choice is one is a three-wire cable with a ground. Also, make sure it’s rated for the amperage you need.

I am running an underground cable in my lawn, what should I use to connect the wires?

You can use waterproof wire nuts if you do not have a waterproof box.

Do you have an extension cord for my window air conditioner?

Yes, you need to use a major appliance cord. A regular extension cord doesn’t have heavy enough wire to safely conduct the necessary current.

How do I create a bend or a turn in conduit?

You can use a connection fitting, much the same way you would use a plumbing fitting, or you can bend the conduit with a conduit bender.

What is the difference between an extension cord rated for outdoor use and a standard one?

The outer coating of the insulation is weather and sunlight resistant.

What is BX cable?

This is a trade name for an armored cable that wraps the wires in a flexible metal sheathing.

Do I need a special kind of fitting for outdoor conduit?

Use a fitting with covers and gaskets, made especially for outdoor use.

How large of a cord should I use when wiring an appliance?

Use cords with 16-guage wire for appliances pulling less than 15 amps and 12-guage wire for appliances pulling up to 20 amps?

What is Underwriters Laboratories?

It is a non-profit organization that tests and approves electrical products. Look for “UL” labels of approval to help ensure appliances are safe.

What do the colors of the plastic insulation mean on wires?

They are designed to indicate their use, but be careful, because they are not always hooked correctly. Hot wires, those carrying current at full voltage, are usually black, red or white with black marks. Neutral wires are usually with or gray. Ground wires are usually either green or bare copper.

Can I bury electrical cable directly under the ground without conduit?

Always check local codes. But generally, UF cable (underground feeder and branch-circuit cable) may be buried without conduit. It is rated for dry, damp, wet or corrosive locations. Do not embed it in concrete. NM (or nonmetallic-sheathed cable) should not be buried due to damage from moisture.

Is it okay to use an extension cord with a fuse on it rather than a surge protector for my computer?

No, a surge protector has components that trip before a spike in electricity damages your electronic equipment.

Can I bury conduit?

Use plastic conduit if you want to bury a conduit to carry an electrical line. Make sure the joints are waterproof.

How do I seal connections I make with plastic conduit?

Use PVC cement found in the plumbing department.

I am installing a ceiling fan; do I need a special electrical box?

Yes, special saddle boxes are designed for hanging heavy fixtures—up to about 50 pounds. Since a ceiling fan moves, these boxes are good for about a 35-pound ceiling fan.

I want to run a new wire to install some additional outlets. Do I have to run these wires through the wall?

You can use surface wire channels that allow you to run the wire on the outside of the wall and still maintain an attractive appearance.

What is an LB fitting?

LB stands for line box. It is often used at the point where you will begin pulling wire through the conduit. However, it is not a junction box and should not contain wire connections.

My dimmer switch feels warm. Is that safe?

It is normal for a dimmer to get warm during operation, and they have a built-in heat sink for that very reason. Always be sure the load on the switch does not exceed its rating.

Instead of using a grow lamp, will placing my plants under a regular fluorescent or incandescent lamp work?

It might, depending on the light. But it probably won’t be as effective. Different stages of plant growth require different light spectra. The initial growing stage requires a blue spectrum of light, whereas the later “flowering” stage is usually done with red–orange spectra. Manufacturers of grow light bulbs design them to product a specific light spectrum range and lumen output to create an ideal growing condition for starting plants.

What is a ground fault (circuit) interrupter?

An electrical device that shuts off the power in case of a short.

What do numbers on electrical cable mean?

They refer to the number and types of wire inside the cable. For example, 14-2 means the cable has two 14-gauge wires inside. 12-3 G means the cable has three 12-gauge wires plus a bare ground wire.

What do the numbers mean on electrical wire?

A wire marked 14/2 means that it’s a 14-gauge wire and it contains two wires inside the insulated jacket.

Do all the sockets in my house need to be a GFI?

Only the first one in the series needs to be a GFI (ground fault interrupter).

I need to replace a lightswitch in my house. What should I get?

You need to know if it’s a single pole or a three-way. If the light can be controlled in more than one location, then it is a 3-way pole.

How can I tell if a socket or switch has a current?

The best way is with a voltage tester. If it blinks, then power is still flowing through the circuit.

My new light fixture is rated for 60W bulbs. Is it OK to use 75W bulbs if I want the room to be brighter?

No. This could cause a serious fire hazard, as the bulbs could get too hot and melt parts of the fixture and even catch on fire.

The plugs in my outlet are very loose. Can this be fixed?

No, you should replace them … immediately. Loose contacts can lead to arcing, which can cause a fire.

Should I use the screw terminal or the holds in the back of the electrical outlet to attach the wires?

Technically, you can use either one. But wires “backstabbed” into these holes (as it is called) are more likely to fall out, which could start a fire. Most electricians recommend attaching the wires to the screw terminals, with the wire wrapped around the screw clockwise, to ensure a solid wired connection when the screw is tightened.

How does a voltage tester work?

A non-contact voltage tester measures the difference in electrostatic charge between the person holding the tester and the tip. If you hold it near an energized cable it will sound or flash (or both). These devices, however, do have limitations, including detecting ghost voltage (or phantom voltage), which has bled over from a nearby energized cable or device. Contact testers (or continuity testers, as they are called) have probes that are inserted into the slots in a receptacle. They can also test for correct grounding to make sure the receptacle is wired correctly. Be sure to read the manufacturer’s instructions carefully before using these products.

I’m replacing a light switch. How do I know which wire should be attached to each screw on the new light switch?

If you are replacing an existing switch, make a diagram of how the wires were attached to the old switch before you remove them. Snap a picture with your camera phone or draw a diagram. Then replace them in the same position on the new switch.

What R-value should I use?

The Department of Energy recommends R-values based on the type of fuel used and where you live. Generally, attics in homes heated by gas or oil in most southern locations should use R-19. For an electrically heated home in the same area, the recommendation is R-30. The minimum recommendation for homes in the coldest climates, regardless of heating method, is R-49.

Will a rechargeable battery ever wear out?

Yes, different brands will last longer than others will. Generally, batteries that are more expensive will last longer, but the savings of the longer life offset their initial expense.

Should I just throw away my old recyclable batteries?

No, laws require that they be recycled. This includes Nickel Cadmium (Ni-Cd), Nickel Metal Hydride (Ni-MH), Lithium Ion (Li-ion) and small sealed Lead (Pb) batteries. You can look for a battery recycling seal on the rechargeable batteries found in cordless power tools, cellular and cordless telephones, laptop computers and camcorders.

What is a time delay fuse?

Time delay fuses are used on circuits where appliance motors have initial surges of electrical power when the motor starts. This initial surge might blow a regular fuse.

I need a circuit breaker, but I don’t have it with me. Are they all the same?

No, it’s best if you bring in the old breaker and match it up. If you know the name of the brand of service box, we could also match it that way. Of course, you can make a guess and if you are right, you can save a trip back.

How do you figure amperage?

It is watts divided by volts. For example, a 1500-watt heater (divided by) 120 volts equals 12.5 amps.

Why are electric heaters limited to 1500 watts?

Because anything over that would exceed the safe amp rating of most wiring and would present a fire hazard.

I have some slots left on my circuit breaker box that do not have breakers in them. Can I add more circuits?

You need to see how many amps your box is rated for and then look at the existing circuits to see how many total amps are already being used. If you have not reached the maximum, it’s possible to add more, but its best to have a professional do the work inside the box unless you have the specific knowledge.

I have a circuit breaker that tripped. Is this dangerous?

Usually the problem is simply an overload and you only need to run fewer appliances on the circuit. However, if it is not overloaded and it keeps tripping, you should suspect a short. Also, look for a defective cord, socket or plug.

Can I add additional outlets to an existing circuit?

You need to figure the current circuit load in watts to see if it can handle additional use. The National Electric Code is 20 percent less than maximum. This means a 15-amp circuit has a safe capacity of 1,440 amps. A 20-amp circuit limit is 1,920 amps, a 25-amp circuit’s limit is 2,400 amps and a 30-amp circuit has a safe limit of 2,880 watts.

Is it all right to replace fuse or circuit breaker with a larger one to prevent them from blowing or tripping?

In most cases the answer is no. They are designed to blow at certain levels to protect equipment and for fire safety.

Do I need a special lamp for this droplight?

I recommend a rough service bulb. These heavy-duty bulbs will take rougher treatment and water droplets.

What is the difference between a floodlight and a spotlight?

The floodlight will have a broader light pattern, and a spotlight will focus on a more narrow area.

Do four-foot fluorescent fixtures come in different wattages?

Yes, the most common are 25-, 34- and 40- watt bulbs.

What is the advantage of a halogen bulb?

It provides brighter, cleaner light. However, they consume lots of electricity and they get very hot. You should ensure that it stays away from draperies, bedding, clothing, and hanging plants.

Do I need to buy a special bulb for my garage door opener?

It’s best to use a rough service bulb.

How can you recognize a socket used for a 3-way lamp?

This socket will have a regular contact tab inside, which all sockets have, plus another raised contact point.

How much energy do compact fluorescent light bulbs save?

Most estimates are 70%, which means that over the life of the bulb you can save as much as $100.

How do I troubleshoot a fluorescent fixture that doesn’t light?

It’s probably not the bulb, because they rarely go bad all at once. Wiggle the tube to make sure it is seated. Replace any damaged lamp holders. Replace the starter. Check the switch and outlet box to make sure it is getting power.

What’s making the tubes in my fluorescent light flicker?

Wiggle the tubes to make sure they are properly seated. Replace any tubes that are dark or have damaged pins. Replace the starter if there is one.

What’s causing my fluorescent fixture to hum?

The ballast probably needs replaced. Another sign of a faulty ballast is black tar like substance oozing from the fixture.

How do I know the size ballast I need for a fluorescent fixture?

You need to know how many bulbs there are and how long they are. However, make sure you check the starter before you change the ballast. In fact, you may want to replace the whole fixture.

How do I check the starter in the fluorescent fixture?

Older, delayed-start fluorescent lights flicker when they first light up. If this last more than a couple of seconds, make sure the starter is seated by pushing it in and turning clockwise. If the ends of the tube light up and the middle does not, the starter is bad. Remove it by turning counterclockwise.

The tubes in my fluorescent light are graying near the ends; does this mean they are wearing out?

Working tubes usually have a gray tinge on the ends, but dark gray or black is a sign that the tube is failing.

My fluorescent fixture does not seem to be putting out as much light as it used to. Could the tube be failing?

If the entire tube is dim, it may simply need washing. Try removing it and wiping it with a damp cloth.

I have low voltage outdoor lighting. Can I add additional lights?

You will have to look at your transformer to determine what its maximum wattage is. Most bulbs are four watts, but they come in different wattages, you will have to add up what you are currently using.

The dryer plug will not fit the receptacle in our new house. How can I remedy this?

In most new homes, there should be four-prong dryer and range receptacles. If you have a three prong power cord, you will need to change it.

What is a polarized plug?

One prong is bigger than the other is. This feature is designed to make sure that a 110-volt plug is never put into a socket that is not a 110-volt outlet.

I have some tools that have three prongs, but the outlet I want to use has only two prongs. Can I safely cut the extra prong off?

No, the third prong is the grounding prong. If you cut it off or use a plug adapter that is not grounded, you will disable a feature that is designed to protect against electrical shock.

Why do some appliances and tools only have two prongs and no grounding prong?

These products are “double-insulated” and do not need the added protection of a grounding plug. You can plug them into ungrounded outlets and still be protected.

Is it easy to replace a faulty plug?

Yes, start by snipping off the original plug. Slide the cord into the new plug, strip the wires and connect them to the proper terminals. For lamps and small appliances there are quick connect plugs. The snipped wire is inserted and a small lever is closed which holds the wire and pierces the wire to make the connection.

What is a ground fault interrupter?

It’s a safety device that shuts off the power if a wire in an outlet develops a leak that could electrocute someone. This hazard is so serious that the National Electrical Code requires all new homes be equipped with them in the bathroom, kitchen, workroom, outdoor, basement, garage and swimming pool circuits.

Do all of the outlets in my kitchen need to have ground-fault circuit-interrupters?

No, if the first in the series is GFCI then all are protected.

I have an older home that does not have ground fault interrupters. Can I install these myself?

Yes, you can replace your regular outlets with ground fault interrupters. If you do not want to rewire the outlet, you can use a portable model that is plugged into an existing outlet.

I need to install a receptacle for my kitchen range. Is it okay to use one designed for a dryer?

No, they may look similar, but they have different features. Make sure you check the manufacturer’s label to ensure you are buying one that is rated for the proper amperage.