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