Common wiring mistakes to avoid

Q. I just had a new two-car garage built and I am remodeling the old one-car garage into a family room. I plan to do some of the wiring myself. What are some of the common wiring mistakes I should avoid?

A. If you have ever seen a new house or remodeling project being wired, it looks pretty simple. The electrician just drills some holes in wall studs and runs some heavy insulated wire through the holes to the various conduit boxes throughout the house.

Don't be fooled. It is much more difficult to do it properly, particularly in a remodeling project where the existing framing is retained. If you make a serious mistake, someone could get electrocuted. Minor mistakes can result in a wire overheating inside a wall. If it gets hot enough, a fire can start inside a wall cavity and spread throughout your house quickly.

The first step is to contact your local building inspectors. Check to see if you need a permit and if an unlicensed electrician is even allowed to do electrical work. If you are allowed to do the work yourself, it would still be wise to have an inspector come to check your work before the walls are closed in order to make sure it meets local codes.

Keep in mind, if you do the electrical work, you are responsible for it as long as it exists. If you sell your house 10 years from now and the new owners are injured due to your unlicensed electrical work, you may be liable.

One of the most common wiring mistakes made is drilling clearance holes too close to the edges of a stud. The edge of the hole in the stud should be no closer than 1¼ inches from the edge of the stud. This is to keep nails, driven into the stud for drywall, from reaching and piercing the insulation on the wiring. If a hole must be closer than 1¼ inches, a protective metal nail plate must cover that area of the stud edge.

Even though it saves time, don't group low-voltage, communication and line voltage (120 volt) lines through the same holes in the studs. Line voltage wires carrying standard alternating current can cause interference with communication wires, such as ones from a computer or telephone. Line voltage wires should always be separated at least six inches from other wiring within a wall.

A more serious problem is if a line voltage line shorts out to a communication or low-voltage wire. This not only can cause a fire to start, but it can destroy any equipment attached to the low-voltage wiring. I have seem the entire low-voltage control system on a furnace destroyed in this way.

Plan all your wiring before purchasing the conduit boxes so you know what size boxes to get. Even the proper-sized wiring can get warm when electric current runs through it. Switches and connections with wire nuts can get even warmer. If you group too many wires, switches, etc., into a small conduit box, it may overheat and become a hazard.

Don't ever hang anything, such as a support for a dropped ceiling or a recessed light fixture, from electrical wiring. This can stretch and weaken the insulation over time which may cause higher resistance, overheating or even a short.

What’s the Story Behind Aluminum Wiring?

According to the U.S. Consumer Product Safety Commission (CPSC), problems with aluminum wiring manufactured prior to 1972 include …

• Expansion and contraction of wires.
• Easily damaged during installation, because it’s a soft metal.
• Corrosion.

Aluminum wiring heats up more easily than copper wire from electrical currents passing through it because it has a higher resistance. As a result, aluminum wire must be one gauge size larger for a given circuit than if copper were used. Thus, a 15-amp circuit could use No.14 copper wire but would require No.12 aluminum. As a conductor, aluminum heats up when a current passes through it. Like any heated wire, it expands and contracts as it heats and cools, but aluminum is damaged more than copper by this cycle of temperature changes.
Adding to this problem are the connections (or terminations) at devices and fixtures. Aluminum tends to oxidize when it comes in contact with some other types of metals—the same ones that often compose the termination material (such as brass terminal screws). Now we’ve got a metal that’s already touchy about heating and cooling, and it’s also corroding and offering even more resistance to the current. The corrosion adds to aluminum’s natural resistance, making that resistance even worse.
As a result …

• The connections deteriorate and loosen at the terminals.
• There is arcing or a discharge of electricity across the gap between the end of the wire and the terminal.
• There is possibly enough heat to melt the insulation and cause a fire. Aluminum wiring can easily be damaged because it’s so soft. If a piece gets nicked while the insulation is being stripped during installation, the nicked area is weakened and can deteriorate faster than the rest of the wire as it heats up. So much for that 50 percent savings in material cost when this stuff was installed!

Aluminum Wiring

Human beings always are looking to substitute new, less-expensive versions of successful products that have been tried and true for years. Sometimes this works well (a cheap, hand-held hair dryer versus a full-size, hair salon, sit-in-the-chair-and-put-your-headinside hair dryer); sometimes it doesn’t (Yugos and Vegas versus most other automobiles). In the electrical world, the use of aluminum wire for running branch circuits falls into the latter category of substitutes gone bad.
Aluminum wire was installed in at least 1.5 million homes between 1965 and 1973. The material cost was as little as 50 percent of the price of copper wire, which made it a hit with homebuilders, even if it ended up being a false bargain for homebuyers. Unforeseen problems with the connections of the wire to devices lead to it being labeled a potential fire hazard and ultimately banned from most residential use. Although I could find no figures as to the actual number of homes that burned down due to electrical fires from aluminum wiring, there were enough to initiate studies, accusations, lawsuits, and not-so-veiled warnings regarding its use. The problem wasn’t immediately apparent because aluminum-wired circuits can take years to reach a failure point while still remaining functional. According to Dr. Jesse Aronstein (in his report “Reducing the Fire Hazard in Aluminum-Wired Homes,” prepared for the Electrical Safety Conference-Electrical Fires at the University of Wisconsin-Extension in March 1982 and revised May 10, 1996), a seemingly indefatigable researcher in this area, “The probability of an aluminum-wired connection overheating in a home varies considerably according to the types of connections, the installation methods used, and the circuit usage, along with many other factors. Without detailed knowledge of the installation in a particular home, it is not possible to provide specific advice on corrective measures.”
Is aluminum wiring a red flag in your house-purchasing adventure? Yes, but there are ways to deal with it intelligently.

Checking Smoke Alarms

The best smoke-alarm systems are connected to your house’s wiring and have a battery backup. A standalone, battery-powered alarm is better than nothing at all, but a wired/battery system is preferred. Check the house for smoke detectors and then check the detectors themselves. Press the test button on each smoke detector. If you don’t hear the annoying screech designed to just about wake the dead, you have a dead battery, a dead circuit, or a dead detector.

Testing The Home Electrical Installation

With a couple of simple testing devices, you can check for wiring problems including …

• Whether power is present at a device or fixture.
• Grounding continuity.
• Defective receptacles, switches, and fixtures.
• Whether outlets are properly wired.

A voltage tester should be in every electrical do-it-yourselfer’s toolbox. Consisting of two probes connected at a plastic housing that contains a small neon bulb, a voltage tester lights up when it detects an electrical current. It also can detect which incoming wire is the hot wire and the presence of a grounding conductor. The probes of the tester either are inserted into a receptacle’s slots or are held against the terminal screws that secure the wire to the receptacle. If the probes do not detect a current when inside the slots but do detect one when held against the terminal screws, this indicates that the receptacle itself needs replacement. If there’s no current at the screws, there’s a problem with the circuit.
Note: With back-wired devices, the probes are inserted in the slots next to the wires. The receptacle will have to be removed from the box. To safely remove the receptacle, turn the power off at the panel first, then remove the screws securing the receptacle, pull it out, and, finally, test it.
After removing the cover plate, be sure the switch is in the “Off” position. Place one probe on the metal box that holds the switch; if the box is plastic or nonmetallic, place the probe on the white or neutral wire. You’ll have to remove the switch from the box in order to reach the neutral wire; be sure to turn the power off first and then turn it on again for your test. Place the second probe on each of the black wires, or on the terminal screws holding the wires if they’re side wired. One of them—the line side or black wire supplying power from the circuit—should light up. If neither of them does, there is a problem with the circuit.
After you find the line side, turn the switch to “On” and place the probe on the other black wire, which is the load side, while keeping the other probe on the neutral wire. In the “On” position, the switch completes the circuit and the load side carries power to the light fixture. If the tester doesn’t light up, the switch is faulty and needs to be replaced. You test a fixture by holding the probes against each of the terminal screws with the light switch “On.” If your test shows a current, but the light isn’t working, you need either a new fixture or new light bulbs.

House Inspection Preliminaries

Note whether the house has fuses or circuit breakers and the size of the service. Look for an overall impression of the condition of the wiring and the number of loads. A sure sign of a shortage of receptacles is the presence of multiple-outlet plug strips or multiple outlet plugins, especially in the kitchen.
Are there enough ceiling lights? Do rooms seem too dark? Keep in mind that every room should have a switch-controlled light fixture. This doesn’t mean the fixture has to be installed in the ceiling or on the wall. A switch-controlled receptacle, a common feature in new homes, meets this code requirement because a floor or table lamp can be plugged into the receptacle and turned on from a wall switch.

With utilities bills soaring, some Seattleites turning to solar power

By Nicole Tsong
Seattle Times staff reporter

Photovoltaic (solar) panels atop Barbara Roberts' and Fred Huntsman's Ballard home ensure they have almost no electrical bills in summer. On sunny days, they can generate a surplus of power that goes back in the grid for other homes to use.

The Seattle Times Barbara Roberts and Fred Huntsman enjoy a cup of tea in their light-flooded kitchen. They decided to remodel their Ballard home using active solar and passive solar, with large double-paned windows that bring in lots of light and some heat.

Stephanie Brown is addicted to reading how many kilowatts her house's solar-powered system has produced. She records output and the weather daily.

Even when the sky is gray and cloudy, Brown's solar system often will generate a kilowatt or two, reducing her electricity bill through winter. In summer, she pays only about $15 per month.

Until 2003, Brown didn't think she could afford to install the necessary equipment to generate solar power on her West Seattle home. But she refinanced her house and used equity to install the more-affordable hot-water system (about $6,000) and the pricier solar electric system ($28,000), known as photovoltaic.

With current tax breaks and incentives, it generally takes 20 to 25 years to recoup the solar investment, said Mike Nelson, director of the Northwest Solar Center, an extension program of Washington State University.

But new incentives from the state that should be available to residents this year will significantly cut the time it takes to make the money back on a solar electric system.

"I decided it was worthwhile for me to be a pioneer," Brown said.

How solar makes sense here

Seattle's gray winters may seem counterintuitive to investing in solar power, but solar experts point to Germany, the world's leader in solar installations, which receives about 70 percent of the sun Seattle sees.

Since solar power is based on light, not heat, solar systems are still making electricity or heating water in winter. Utilities in Washington state also allow you to bank your summer production and use it in the winter.

The average Seattle home with a solar electrical system receives about 25 to 50 percent of its electricity from the sun, said Nelson. Use electricity conservatively, and it can go even higher.

Solar energy includes active solar, which converts light into energy using equipment or materials, and passive solar, which uses light and heat without additional equipment.

The two most common types of active solar systems for the region include:

• Solar thermal systems: This hot-water system uses solar power to heat water that — in a heat exchange — heats your hot water. The system, which requires a second tank, can be used with electric or gas hot-water systems, and even with on-demand water systems that don't include a tank.

• Photovoltaic systems, or solar electric: This system uses photovoltaic (solar) panels to collect electricity from the sun and transfers it through an inverter into your home's electrical system.

State law requires electric utilities here to provide net metering, which allows you to "bank" electricity your home produces that you don't use, which instead goes into the general grid. You get credit for the energy later.

What does it cost?

Conventional solar electric systems range from $6 to $10 per watt installed, according to the City of Seattle. A 2,000-watt or 2-kilowatt (kW) system would cost $12,000 to $20,000 and generate about 2,000 kilowatt hours per year. The average 2,000-square-foot house in Seattle uses about 10,500 to 11,000 kilowatt hours per year.

A thermal system for heating water typically costs $5,000 to $6,500, said Pam Burton, president of Solar Washington, a nonprofit solar advocacy group.

But the state has new production incentives for utilities to pay solar owners 54 cents per kilowatt produced from solar modules and inverters (which synchronize electricity collected to the grid) made in Washington. For a 3-kW system, that would be roughly $2,000 a year, Nelson said. (A new factory is being built in the state that should provide the modules later this year.)

With those higher payments and other federal tax breaks and state incentives, owners can effectively recoup their investment in seven years once the factory-built panels are available in our state, Nelson said.

When the state authorized production incentive payments of 15 cents per kilowatt produced in 2005, solar systems installed in Washington jumped from about 30 that year to nearly 450 in 2006, he said.

Net metering that lets you bank electricity also makes solar systems more affordable, and the sales tax on photovoltaic and solar hot-water system equipment and installation is waived until 2011.

Nelson considers solar systems an investment similar to the debate on buying a house vs. renting.

"Remember at the end of that time you spent your money, you [still] have it all," he said. "If you bought the electricity, you'd have a drawer full of receipts. The difference is, do you want to be a renter or an owner?"

Passive solar

For those who can't or don't want to invest in an active solar system, passive solar is another option that can be incorporated into remodels or new construction.

Passive solar means siting a building or placing windows, for example, in a way to take full advantage of natural sunlight and using interior materials that retain heat from the sun, such as water, concrete floors or adobe. It also can include natural ventilation, according to the American Solar Energy Society.

Passive solar makes more sense in Eastern Washington, where there is more sunlight, Nelson said, but designing your home with plenty of quality windows for lots of light and good insulation will conserve electricity and heat anywhere.

The big payoff

Barbara Roberts and Fred Huntsman, who added photovoltaic and hot-water systems to their 1929 Ballard home, also included passive solar design in their kitchen remodel, which floods the room with light and provides some heat. With almost no electrical costs in the summer, they say they are thrilled with the results.

"It just makes me happy that I'm doing something in a positive motion instead of being reactive," she said. "It's green, it's not going to pollute the air and I like that tremendously."

Stephanie Brown's electric bill is half of what it once was — $40 to $50 per month in the winter, down from $125 to $140 despite an electric baseboard heating system. Her gas bill is steady at $14 to $16 per month, and her three-person household never runs out of hot water.

She loves her solar lifestyle so much that she's considering installing a solar space-heating system for her basement, with radiant flooring that works by either the sun or water heater warming water in tubes underneath the floors.

"I had several people that said, 'Oh, I didn't think you could do all that in Seattle,' " Brown said. "Trust me, in the summer, the sun is north of us, we're getting plenty."

Nicole Tsong: 206-464-2150 or ntsong@seattletimes.com

Who Does the Inspection?

Professional house inspectors are very much a mixed bag. Some are extremely thorough and produce very detailed reports; others are less-impressive and depend too much on checklists and filling in the blanks. The very best person to inspect your electrical system is a licensed electrician, but you don’t want to be dragging one along every time you look at a prospective house. Save that for final candidates. Meanwhile, you can do a preliminary inspection yourself.

Caveat Emptor or Buyer Beware!

Whether it’s new, old, or in its teenage years, you’re taking a certain chance when you buy a house. All the warranties and assurances in the world won’t prevent leaks, squeaks, and lawsuits over roofing or siding materials, for example. I can speak from experience on the last one, because our house—purchased new in 1994—features the infamous Louisiana-Pacific LP Siding, the subject of a massive class-action suit and a multi-million-dollar settlement. The same scrutiny applies to electrical work. You have the law on your side with seller disclosure Form 17 and builder warranties, but you want to preclude any problems after you move in by ferreting them out before signing the final papers. An inspection and a disclosure form keep a seller honest and can bring up unseen problems that were unknown even to the seller.

Examine your prospective house

Your electrical inspection and checklist don’t just apply to your current home but also to a prospective residence. Despite the diligence of inspectors, they still can make errors when checking and approving newly constructed homes and remodeled additions. Any home purchase, regardless of the age of the house, should include a general inspection and an electrical inspection. This inspection will be more exacting than one in your own home because you will have no familiarity with a house that’s new to you, whereas you already know that your kitchen lights start flickering an SOS in Morse code every time you turn on your food processor and that they need to be corrected. An inspection will tell you more than simply the condition of the system. It will enable you to consider changes and additions and their possible costs before you buy. These factors can affect your purchase negotiations, especially if major work is called for such as installing a new service panel.

New homes, both those of your own design and those under construction by developers, deserve special attention with regard to your electrical needs. The planning and construction phases are certainly the ideal times to wire for as many light fixtures, receptacles, dedicated circuits for your computers, and specialized cable for phones and media as you desire. If you’re not sure about future TV or phone locations, wire every room for them and don’t worry about it. The labor cost to install wiring is far cheaper when the walls are open to the framing studs than after they’re finished.

When New and Old Collide

Old electrical systems can be safely added onto if the following considerations are followed:

• You have room in your service panel or fuse box for additional circuits.
• Individual existing circuits aren’t fully utilized and can carry an additional load.
• The wiring and insulation of these circuits are intact and not worn.
• You properly join new wire to old.
  

You can’t see inside your walls and observe how every receptacle, switch, and light has been wired, but you can get an idea if an addition has been made to the original system.Look for the following telltale signs:

• A receptacle or switch style that doesn’t match the others in your house (The cover plates also might be a different style.)
• A fixture located in an odd place such as a crawl space
• A receptacle that isn’t as evenly spaced as others
• A receptacle that is cut into a plaster wall while all the others are cut into the baseboards—a common feature in turn-of-the century homes
• Any switch or receptacle that is surface mounted on a wall rather than cut into the wall

Do you have unfinished attic or basement space? These are prime areas for added fixtures to be tied into existing wiring and should be checked thoroughly.

Good Wire, Bad Wiring

An original service of knob-and-tube wiring, if properly installed, is and can remain a safe electrical system. Left alone, it would satisfy the electrical demand for which it was designed without any problems.
When it isn’t left alone, or when the loads increase and stretch the system’s capacity, the problems and hazards begin. Add-ons are pretty easy to spot, especially those done by homeowners. Dead giveaways include …

• Sloppy installation.
• Loose, unsecured wires.
• Wires running across the edge of floor joist rather than passing through them in unfinished basements.
• Improper taping at connections through the use of unapproved materials such as masking or adhesive tape.
• Mixing two different gauges of wire on the same circuit.

Other issues include worn and frayed insulation and brittle wire ends where they are attached to loads or switches. This problem is exacerbated as the wire ends get bent and unbent when switches, receptacles, and light fixtures are replaced over the years due to general wear and tear or the desire for something new.

Jump Up to 200 Amps

If you’ve got a small service, say up to 100 amps with a fuse box, in a two-story house and you’re thinking of upgrading to circuit breakers, replace it with a 200-amp panel. Don’t argue about it or debate its need, just do it. The last house we owned was a 1924, three-bedroom, one-story bungalow on a street of one-story bungalows. You could easily maintain that it only needed a 125-amp service, but a funny thing happened as Seattle real-estate prices headed toward the stratosphere: These one-story homes started becoming two stories. Owners decided it was more cost-effective to stay put and add on rather than to move. Five of our former neighbors on one block did this very remodeling to their homes. My point is that you cannot predict future needs. Given the relatively small cost difference between a 125-amp service and a 200-amp panel, there’s no point in installing the smaller service in a two-story house. One exception to my 200-amp rule is the presence of gas appliances. Our first house, for example, was adequately serviced by a 125-amp panel because we had a gas furnace, water heater, stove, and clothes dryer. As a result, the biggest single electrical loads in the house were the refrigerator and the washing machine, neither of which were huge draws on the system.

Do You Need to Replace the Existing Circuits?

Installing a new 200-amp service panel in an older, two-story house, replacing all the existing circuits, and adding new ones to bring the entire system up to code—all this is an expensive proposition. The service alone can cost roughly $1,800 to $2,000. You can easily spend four times that amount wiring the house, depending on its size and the complexity of the new system. I hesitate to quote figures because every house is different, as are local labor rates, but an electrician can give you a ballpark figure, which is subject to change when an actual estimate is drawn up. Some people will replace and upgrade just to be on the safe side, while others should replace and upgrade. The following are signs that you should consider changing your electrical system:

• An undersized service (60 to 100 amps for a large, two-story, all-electric house)
• An insufficient number of circuits
• Too few receptacles and switch-controlled lights
• A lack of GFCIs
• Overloaded circuits with fuses that burn out regularly
• Frayed or deteriorated insulation on your current wiring Too often, homeowners ignore the basic mechanics of a house (electrical, plumbing, and heating/air conditioning) when remodeling and pay too much attention to aesthetics, such as cabinetry, painting, and floor finishes.

It’s easy to understand why: These are characteristics we see day after day. No one sees the new, modern, sheathed cable running through the walls to equally new grounded outlets, all of which are nicely distributed on properly sized circuits. I can’t begin to count the number of older homes I’ve been in that were beautifully redecorated but still only had one or two receptacles—and old receptacles at that—per room. There’s no excuse for living in an underpowered house as we begin the twenty-first century.

Wire Systems Old and New

A main difference between old electrical systems and new ones is the presence of a grounding conductor in contemporary wiring. Modern cable contains all three wires—hot, neutral, and ground—wrapped in protective thermoplastic insulation. Your house might have cable running through it rather than the old knoband-tube or metal-wrapped BX cable systems, but this is no guarantee that it’s got a grounding conductor. Cable installed in the 1950s only contained a hot wire and a neutral wire. The only way you’ll know for sure with your own cable is to check your electrical panel. You’ve already read that old wiring isn’t necessarily bad wiring, with the (sometimes) exception of BX cable, which can become damaged and be conducive to short circuits. The abuse usually occurs later as it gets hacked into. Replacing an entire system is expensive. New services installed in older homes usually incorporate some of the existing wiring into the new panel (unless it’s judged to be too corroded or unsafe). You and your electrician need to decide …

• If you can add any loads to your existing system.
• The compatibility of your current wiring with a new service panel.
• Whether your system is safe given its current usage.
• The practicality of completely rewiring your house.
• The cost versus the benefits.

What is GFCI — Ground-Fault Circuit Interrupters

The code requirement to install GFCIs has been a real lifesaver for homeowners. One government statistic suggests that a GFCI installed in every home in America could prevent more than two thirds of all residential electrocutions. A GFCI measures the current flowing into the outlet through the black or hot wire and the current outflow through the neutral or white wire (see the following figure). If the GFCI detects any difference greater than 7 milliamps, it shuts off the current. Why? Because any difference in the current is an indication that the current is somehow shorting or “leaking”—maybe through you! It might be a short in an appliance such as a hair dryer or an electric mixer. These are dangerous situations, and a GFCI will shut down far faster (in as little as 1/40 of a second) than a standard circuit breaker or fuse.
An older home may or may not have GFCIs, but it can be retrofitted with them. A GFCI won’t always prevent an initial shock, but it does prevent a lethal one. The current NEC calls for GFCIs to be installed in a number of locations, including …

• Bathrooms.
• Kitchen counters.
• Outdoors.
• Garage walls.
• Unfinished basements and crawl spaces.

Why have these areas been singled out? They all have something in common: water or water pipes, both of which are good at seducing a current away from its righteous path back to your panel or fuse box to take a trip through your body instead. There’s a reason why various cads in the movies get knocked off while in the bathtub when an irked female character throws a plugged-in curling iron into the water. If you use a defective hair dryer when touching the water faucet in your own bathroom, you’ll be glad you have a GFCI installed.

A modern electrical system will have GFCIs in the form of either outlets or breakers, although the latter are more expensive. The presence of a GFCI in an old system is a demonstration that a past owner was concerned enough to attempt at least a partial modernization of the system.

Fixing Electrical Equipments with Friends?

You’ll be testing your circuits one at a time. It’s just a matter of flipping a breaker or removing a fuse, observing what goes out, and writing it down. This means every light will have to be turned on, and every receptacle will need something plugged into it. This is where the lights and radios come in. It’s important that you know where every receptacle and odd light is located and that you account for all of them. As previously mentioned, this job is easier to do if you can fill up your house with some friends. As you turn the power off one circuit at a time, they can yell out what went off, and you can write it down in your notebook. This can be a fun project in a big house with people running and shouting as lights go off all over the place. Carefully write down everything as specifically as possible and redo the list later on your computer. Print a list to attach to your service panel or fuse box, and maintain the file on a disk to record new circuits as they are added or old ones as they are changed.