What Do Surge Suppressor Do?

In addition to making surge-suppressor salespeople happy when they sell them, a surge suppressor protects all the electronic equipment we seem to have around our homes these days, from computers to VCRs. A suppressor, which typically goes between your electronic equipment and a receptacle, detects a voltage increase and prevents it from continuing into the equipment.
Safety, Tools, and Contractors What should you consider protecting? Anything with a microchip such as …
➤ Computers.
➤ Televisions, VCRs, and stereos.
➤ Telephones and answering machines.
➤ Microwave ovens.
Why telephones? Phone lines and cable lines run in close proximity to power lines. An electrical surge could travel down the phone or TV line instead of the power line. Not only your phones but also your computer could be damaged if it has a modem and is connected to your phone line.

Surge-Suppression Devices

Electricity is like human relationships: It has its peaks, its low points, and a lot of time in between when it just muddles through without causing much excitement. Left to its own devices, it probably would muddle through day in and day out, but we (and a lightning storm or two) interfere and cause surges and spikes. What are they? Simply put, they are increases, usually sudden, in electrical voltage. Surges differ from spikes in part by how they occur.
Surges can result from …

• The energy demand when a large appliance is first turned on.
• Routine maintenance and switching by your utility company.
• The rush of current to your house after power that was cut off is turned on again. Spikes, on the other hand, most often are caused by lightning or by cars running into power poles. Spikes can send as much as 6,000 volts down your line.

A surge is apparent when you turn on a garbage disposer or a laundry-room appliance. The appliance requires a surge of power to get rolling. This is the same principle behind moving a stationary body: The initial force or power required is greater than the amount needed to sustain movement. The first few pushes you give your kids on a swing require more energy than later ones after momentum has been established.

Multiple-Outlet Devices

If you’ve got a computer and its peripherals (a printer, scanner, and ZIP drive), you probably have a power strip of some kind unless you specifically wire a room of your house as you would an office and give yourself plenty of receptacles. Power strips usually are rectangular-shaped with four or more individual outlets and a built-in circuit breaker. Most power strips in hardware and discount stores are an all-purpose type and are not appropriate for computer use. Leviton, for example, makes computer-grade strips that, according to the catalog, feature “EMI/RFI noise attenuation for microprocessor-driven electronic equipment.” They also provide surge suppression.
You can add receptacles by using outlet box lampholders. These typically are porcelain light fixtures with pull chains to control the lights (instead of a switch). Some of these lampholders, often found in unfinished spaces in a house, come with built-in outlets. These really are meant as a temporary power source, not for running multiple power tools. Remember, as a lighting circuit, it’s most likely running on only 15 amps. Note that in a crawl space, the receptacle on a porcelain lampholder must be GFCI-protected.

Homemade Cords

Once in a while, I run across a home in which a contractor used extension cords made from nonmetalic cable with a plug spliced on to one end and a pair of receptacles in a box on the other. You would never see this on a large commercial job because it would be considered a safety hazard. The more creative guys attach the receptacles to a wood stand with a plywood base so a work light can be mounted. I don’t see any clear advantage to messing around with made-on-the-job cords like this when an approved 100-foot, 12/2 extension cord can be purchased for a modest amount of money and will last for years.

Understanding extension cords rules

Extension cords come with warnings and usage guidelines just like every other consumer product. Some of the best advice comes from fire departments and the Consumer Product Safety Council, both of which have experience with the injuries and destruction caused by misuse of extension cords and power strips. Here’s a list of extension cord do’s and don’ts:

• Use extension cords for temporary use only.
• Unplug extension cords when they’re not in use.
  
• Only use cords having gauges that are properly matched to the load and the current to be drawn.
• Only use cords outside that are specifically marked for this type of use.
• Only use polarized receptacles with polarized cords.
  
• Never remove the grounding prong from the plug of an extension cord to fit it into an ungrounded receptacle.
• Regularly inspect your cords for damage.
• Never splice a damaged extension cord or one cord to another.
• Do not run cords across or through wet areas or puddles.
  
• Hang cords high off the floor to avoid tripping hazards on work sites. Don’t allow cords to hang from counter- or tabletops where children can pull on them.
  
• Cover any unused sections of the cord’s outlet end with safety caps to keep children from inserting objects.
• Replace damaged or worn cords.
• Always stretch out the cord, and never cover it with rugs, carpets, clothing, or heavy objects. Cords can build up heat if they are used when coiled or looped.
  
• Extension cords are temporary wiring. Don’t attach them to walls or woodwork with staples or nails that can damage the cord and present a fire hazard.
• Don’t plug extension cords together. Instead, use a single cord long enough to do the job on its own.
• Buy cords that have been tested by an approved testing lab such as Underwriters Laboratory (UL) or Electrical Testing Laboratories (ETL).

When Extension Cords Go Bad

In the 1960s, the first recalls of defective or assumed-defective automobiles began, and we’ve been recalling consumer products ever since. Surprisingly, there have been a number of extension-cord recalls, although they don’t get quite the same publicity as, say, recalling the family minivan because the wheels have a tendency to fall off. The following is a list of recent recalls, courtesy of the Consumer Product Safety Commission:

• Approximately 230,000 extension cords manufactured in China and distributed by a Texas firm were recalled due to undersized wires and improper plugs, according to a September 20, 1994, announcement.
• In a May 29, 1997, press release, the General Cable Corp. announced the recall of 2,700 outdoor extension cords sold under the Carol and Ace brand names due to an exposed wire near the receptacle. No injuries had been reported from the use of these cords.
• A Miami, Florida, firm recalled almost 6,600 extension cords and power strips in 1998 due to undersized wires that could not carry the advertised load, improperly polarized plugs, and no overcurrent protection in the surge protectors.
• A February 24, 1999, press release warned consumers about two million faulty extension cords, power strips, and surge protectors involved in 25 recalls since 1994. An ongoing investigation started in 1997 found that most of the faulty cords were made in China, were sold at discount stores, and in some cases, had counterfeit UL certification labels.

This doesn’t exactly inspire confidence, but it’s useful because it provides the motivation to inspect and check your extension cords on a regular basis. On large construction sites, monthly testing of extension cords for grounding is mandatory, as is recording the test results. Cords that pass inspection are marked with a piece of colored tape. (The color changes monthly.)

One Extension Cords Size Doesn’t Fit All

Extension cords are measured by their wire gauge size just like the wires running inside your walls. Their ampacity rating uses the same American Wire Gauge (AWG) standards: the smaller the number, the thicker the wire (which means it can carry a larger current because it offers less resistance). This is especially important with longer cords because a current loses some voltage as it travels over a conductor, and this can affect the performance of a device (such as a power tool) on the other end. When the voltage drops, any electrical equipment on the cord will pull more current to compensate for the lost voltage. This generates more heat, which causes damage to the tool. The longer the conductor, the greater the voltage drop. Contractors usually use a 12/2 extension cord to run their tools, and you should, too.
Typically, extension cords are available in 10, 12, 14, 16, and 18 gauges. An 18-gauge cord is the size normally used for very small loads such as lamps or clock radios.
The following table shows typical extension-cord lengths and gauge combinations.

What the NEC says about extension cords?

Extension cords aren’t permanent wiring, so the National Electrical Code doesn’t apply to them per se, but it does lay out some guidelines. The NEC would prefer that you use a close-by receptacle, but that’s a little unrealistic if you’re running an electric lawnmower, for example. The code recognizes that extension cords are meant only for temporary use for portable loads that aren’t fixed to one specific location.
What about a table lamp and clock radio by your bedside connected to a small-gauge extension cord because the only receptacle on the wall is beyond the length of their appliance cords? The NEC would like you to install a new receptacle, but sometimes this isn’t practical. If you’re renting, you would have to convince your landlord/landlady to accept this additional expense. For such a small load, the use of an extension cord on a regular basis isn’t a big deal. Problems occur, however, when extension cords are used to run large loads on a more or less permanent basis. Small extension cords become a bigger problem when they are installed under a rug or are in any way covered over so they retain heat.

Understanding Extension cords

Think of an extension cord as a portable, impermanent form of wiring. It’s subject to the same laws and limitations as any other electrical conductor, which means it can be overloaded, it can short out, and its insulation can melt. On top of that, they’re easy to trip over when they’re left lying around a work site. Extension cords are handy and necessary, but they need to be used carefully and inspected before each job. According to the Consumer Product Safety Commission

• More than 3,000 residential fires each year are attributed to extension cords. Most of the problems are the result of short circuits, excessive loads, and misuse of the cords.
• Hospital emergency rooms treat more than 2,000 injuries each year associated with extension cords. These injuries include fractures, lacerations, and sprains from tripping over the cords. About half of the injuries to children are caused by electrical burns to the mouth.
• Tens of millions of dollars in fire damage occur yearly as the result of misuse of extension cords.

You might never look at an extension cord in the same way again!

Home-Improvement Stores vs. Electrical Wholesalers

Electricians usually do their shopping with suppliers whose stock and trade are electrical components. Large commercial companies always shop at these establishments. They don’t share their space with paint, kitchen cabinets, or coupon specials. They also don’t operate quite the same as a retail establishment. This means …

• Don’t expect them to explain how to do your wiring or use the tools.
• Very little will be on display, so you’ll need to have a clear idea of what you want when you go in.
• If a store is wholesale only, it might sell only to contractors. The advantage of shopping at a wholesale supplier used to be the range of supplies and devices available, but in recent years, the large homeowner-oriented building-supply stores such as Home Base and Home Depot have narrowed this gap in the residential categories.

A trip to our local Home Base found Square D, Cutler-Hammer, and Westinghouse service panels available as well as a huge variety of boxes, conduit, cable, connectors—you name it. These stores are geared toward do-it-yourselfers who need to see the components and fixtures instead of trying to order them blind at a wholesaler. They also order merchandise by the trainload and usually have competitive prices.