With everyone talking about datacom cabling, structured wiring, data centers, fuel cells, power-quality problems, deregulation and re-regulation these days, it's easy to overlook the bread-and-butter work of so many CEE News readers: Good, old-fashioned residential power wiring.
While residential new construction has tailed off a bit since booming in the mid-1990s, there's always been a steady stream of home remodelling and electrical upgrades to keep electricians busy. According to a CEE News study, more than 50% of residential electrical contracting projects are renovations. By some estimates, more than 20 million U.S. homes would need a major wiring upgrade to meet today's electrical standards.
Many of these houses were built in the post-World War II construction boom that gave birth to the sprawling American suburb. The most famous suburban subdivision, and arguably the first, Long Island's Levittown, offered the parents of today's baby boomers prefabricated cookie-cutter houses as a stepping-stone to the American Dream. The small Cape Cod style houses that characterized Levittown quickly multiplied outside of major cities across the United States. Fifty years later many of these homes have since been expanded with additions to accommodate extended and two-income families and a wealth of new appliances.
Of course, many of these aging suburban dwellings still wheeze by on their original electric systems. Multiple appliances overburden single 120V wiring systems, multiconductor wiring and original fuse boxes.
Although many older houses are inadequately wired, no code requires home owners to upgrade old wiring that works. Of course, any new electrical work must be done according to the latest electrical code. In addition, if an owner renovates one portion of a house's wiring, the electrical inspector most likely will require him to rewire the entire house.
Most owners upgrade their old wiring simply because they need more circuits to power their modern appliances. Increasing electrical-system capacity also increases the resale value of the home. Some older houses have only one 120V system instead of today's standard of two systems totaling 240V. When a do-it-yourselfer homeowner needs more circuits, he'll often throw up his hands, put away his tools, and turn to a professional electrical contractor who knows how to rewire in accordance with the National Electrical Code.
Many older homes still have a 60A, three-wire service. The National Electrical Code recommends that individual residences be provided with a minimum of a 100A three-wire service. CEE News Contributing Editor Joe Tedesco said a 100A service provides safe and adequate electric supply for the lighting, refrigerator, an 8,000W cooking range and other appliances requiring a total of up to 10,000W altogether.
Some older homes have only a 30A, 115V, two-wire service. This system can safely handle only a limited amount of lighting, a few minor appliances and no major appliances. Therefore, this size service is substandard in terms of modern household needs for electricity. Furthermore, the service constitutes a fire hazard and a threat to the safety of the home and the occupants. If an owner wants to rehabilitate a 30A, 115V home for the new millennium, he'll do best turning to a professional, qualified electrical contractor.OUT ON THE ISLAND
Bill Addiss, principal of Addiss Electric in Centereach, N.Y., (Long Island) said he believes a common cure for the middle-aged home is upgrading the service equipment. “This sometimes means replacing an old fuse box with a modern panelboard and circuit breakers. The owner usually sees this as a monumental improvement and, therefore, a justifiable expense.” Addiss, however, said he worries about owners not also springing for more-important electrical upgrades such as replacing threadbare SE cable, rusty or corroded service equipment.
Performing mostly residential and light commercial work and specializing in residential remodeling, Addiss usually works alone wiring houses within a tight 10- to 15-mile radius of his own home. Much of Addiss' work comes by referral, but sometimes he joins with other contractors on larger jobs or comes in as a subcontractor.
Establishing his firm after passing his Masters' license in 1985, Addiss said he finds residential renovations “particularly satisfying in instances when the plan comes together. Although not as technically demanding as some other types of electrical work, it can be very challenging.”
He also home owners always benefit from the sound advice of an experienced electrical contractor.
“While changing one component of the system may remove any imminent danger, it is almost always prudent to also upgrade the rest of the service to the present norm (or better). As far as the size of the service goes, it is usually not a very large difference in cost between a comparable replacement and the upgrade,” he said.
A complete “gut” job, in which walls are open and wiring is simply replaced according to present codes, is the best and easiest way to get rid of poorly connected aluminum wiring installed in many homes during the 1960s and 1970s, Addiss said. “Old two-wire cables can be replaced with grounding types and three-prong receptacles can be installed and spaced according to present requirements,” he said. “Furthermore, GFCI and AFCI devices can be installed where required. Dedicated or larger circuits (if necessary) can be installed for the modern appliances requiring them or in areas having special requirements.”REELING IN THE YEARS
Several residential wiring methods have come and gone since the dawn of electrical contracting in the 1880s. The oldest residential wiring system today's contractors encounter is called knob and tube (K&T). Porcelain K&T, installed in homes until about 1950, kept the black and white hot and neutral wires running separately. Basically, K&T consists of individual conductors with cloth insulation. The wires run through ceramic tubes along joists or studs supported by ceramic knobs. Electricians made K&T connections by twisting the wire together, soldering and wrapping it with tape. Often perplexing to today's contractors, K&T wiring still holds up because yesterday's electrically paranoid contractors built the wiring to last. Also, because K&T wiring is so simple, it's easy to replace if a homeowner desires more circuits.
“We have had a number of concerned home buyers and realtors asking if we consider knob and tube wiring safe,” says David Casemore, president of Casemore Electric, Royal Oak, Mich. (See “Casemore's tips”). Our answer, in most cases, is ‘Yes.’”
Contractors began installing multiconductor cable in the 1940s. Except for not having a grounding wire, it looked like and installed like the Romex wiring installed in the 1950s and 1960s. Multiconductor wiring's major drawback is that it becomes brittle with time and breaks. The best thing to do with old-style BX is to replace it when there's any sign of degradation.
After multiconductor cable, the more modern Romex was invented. Basically asphalt covered cloth sheathing, the sticky Romex lasts a long time and is easy to work with. In fact, it's generally as safe as today's thermoplastic insulation wire.
Aluminum wiring is another story. Installed in many homes from the mid 1960s to the early 1970s, it quickly gained a reputation as a fire hazard. Fire and deaths have been caused by aluminum wiring, according to the U.S. Consumer Product Safety Commission. When improperly installed, problems due to expansion can cause overheating at connections between the wire and devices (switches and outlets) or at splices. CPSC research shows that “homes wired with aluminum wire manufactured before 1972 are 55 times more likely to have one or more connections reach fire hazard conditions than are homes wired with copper.” Post-1972 aluminum wire is also a concern. Introduction of the aluminum wire “alloys” in 1972 did not solve most of the connection failure problems. Aluminum wiring is still permitted and used for certain applications, including residential service entrance wiring and single-purpose higher amperage circuits such as 240V air conditioning or electric range circuits.CASEMORE'S TIPS
As the preceding paragraphs show, renovation electricians can encounter some weird wiring as they dig like archeologists through layers of time.
These residential renovation guidelines come from David Casemore, president, Casemore Electric, Royal Oak, Mich. About 90% of Casemore's business is residential, about 80% of which is renovation. Founded in 1979, Casemore Electric employs four electricians, whose typical tools of the trade include fishing rods, chains, hooks and long drill bits.
Upgrading load centers. To meet expanded electrical loads, Casemore finds that the newer 30-space 100A main-breaker load centers have been very useful. “Perhaps the customer has a 100A service with a meter cabinet, riser and service-entrance cable in good condition but the existing load center has only 16 or 20 spaces, all of which are used. Our firm swaps out the panel only (plus add a ground rod and also a grounding electrode conductor over to the water service entrance pipe) and come up with several spaces for new branch circuits. So often these days a house will have many branch circuits but a total calculated load of much less than 100A. We replace fuse panels with circuit breaker panels very often, not just in rare cases.”
Replacing wiring that has deteriorating insulation. “This is a common problem with wiring in attics that has been subjected to extremes of hot and cold. It's a problem because many people can't afford to rewire an entire house. Our firm recommends removing old knob and tube wiring from attics and exterior walls before adding or blowing-in new wall or attic insulation. Another problem area is installing replacement light fixtures on outlet boxes that have old, deteriorating wiring in them. Not only is the wire and insulation old, but people often install bulbs with too high a wattage rating for the fixture. Kitchen lighting outlets tend to be in the worse condition because people want a lot of light in the kitchen and the kitchen light is left on all day and late into the evening in many homes.”
Properly replacing “two-prong” receptacles with grounded receptacles. “The code allows replacement plugs of the three-prong type without the need for a ground wire if the outlets are GFI protected and labeled so. My firm rarely does this. It may be safe (until the GFI goes bad, that is), but some appliances (electronics) that have a three-prong cord may actually work better if a real ground is present. In fact, a surge protector outlet strip will offer no surge protection unless it is properly grounded. We will install a replacement ‘two-prong’ receptacle (yes, you can still buy them, but I don't that any decorator-style two-prong ones are still made) in an area where it is unlikely that anything with a three-prong plug will be used (living-room table lamp, bedroom clock-radio etc.). In all other areas we recommend fishing in a ground wire.”
Adding telephone and data jacks for computers. “Don't even think about using the old “quad” wire (four wires: red, green, black and yellow). It's no good for multi-line phones or even for fax or modem use. Besides, the FCC says “no” to further installation of quad wire. We run Cat. 5 for phone lines (Cat. 3 is okay, but Cat. 5 does not cost much more, and this way we only have to stock one type). Running or fishing wires is not easy, so we always run two Cat. 5 cables to each wall jack. All cables are “home run” to a common area), which gives the client an instant computer network.
Replacing aluminum branch circuits. “Not everybody can afford to rewire an entire house, although this is the preferred method with aluminum branch circuit wiring. Our company has gone through houses and put copper pigtail wires onto the aluminum wires using a twist-on connector that is listed for use with copper-to-aluminum connections. So much has been said about the dangers of aluminum wire that I've had to inform people that there's nothing wrong with their aluminum service cable or range cable and that it only applies to 15A and 20A branch circuits. Many people are surprised to learn that it's the terminations and not the wire itself that is the problem. I even had one ‘home inspector’ tell a person who was about to purchase a turn-of-the-century house that the house was wired with aluminum wire. They almost backed out of the deal but asked me to look at it. What I found was the original copper wire, which was ‘tinned’ for soldering, so it had a shiny, silver color to it.”
Probably the best advice for any contractor is to always remember you're drilling and pulling wire through the walls of people's homes. Here's where being friendly, professional, quiet and, above all, careful, will win new customers.
“Care must often be taken to avoid unnecessary damage to areas outside the scope of the project,” Bill Addiss said. Adding or replacing lighting fixtures may require replacing older wiring types with modern 90°C type, additional circuits and wiring for increased switching flexibility,” Addiss said. “Additional receptacles are sometimes needed to meet more stringent, modern spacing requirements.”
“For the best customer satisfaction, leave the least possible damage and expense,” Addiss said. “Here is where patience and ingenuity are true virtues and an opportunity to let your professionalism shine.”COMMON ELECTRICAL VIOLATIONS
According to the National Center for Environmental Health, the crucial elements of an electrical system that a housing inspector must check include the power supply; the types, locations, and conditions of the wiring in use; and the existence of the number of wall outlets or ceiling fixtures required.
Power supply — Where is it located? Is it grounded properly? Is it at least of the minimum capacity required to supply current safely for lighting and the major and minor appliances in the dwelling?
Panel box covers or doors — These should be accessible only from the front and should be sealed in such a way that they can be operated safely without the danger of contact with live or exposed parts of the wiring system.
Switch, outlets and junction boxes — These also must be covered to protect against danger of electric shock.
Frayed or bare wires — Time and temperature, or constant friction, dry out and crack the insulation, which leave the wires exposed.
Bathroom lighting — It should include at least one permanently installed ceiling or wall-light fixture with a wall switch and plate to avoid short circuiting from water contact. Fixture or cover plates should be insulated or grounded.
Lighting of public hallways, stairways, landings and foyers — A common standard here is sufficient lighting to provide illumination of 10 footcandles on every part of these areas at all times.
Habitable room lighting — The standard here may be two floor convenience outlets or one convenience outlet and one wall or ceiling electric light fixture. This number constitutes an absolute and often is inadequate given the electrical loads on most homes.
Outlet covers — Every outlet and receptacle must be covered by a protective plate to prevent contact of its wiring or terminals with the body, combustible object or splashing water.
Electrical Wiring: Residential. By Ray Mullin. Delmar Publishing, 1998. $57.95. Walks you through every aspect of wiring the single-family home.
Old Electrical Wiring. By David E. Shapiro. McGraw-Hill, 1998. $39.95. This book helps electrical professionals deal with virtually any difficult electrical problem encountered in old houses.
How to Recognize Electrical Code Violations. By Joseph A. Tedesco. Builder's Book, Inc., 1999. $36.95. Includes more than 100 photographs of Electrical Code Violations. Illustrates fire and electric shock hazards, and NEC violations.
Residential Electrical Estimating. By John E.Traister. Craftsman Book Company, 1995. $29.00. Includes hundreds of unit prices for installing every type of residential electrical work.