Beware of Fire Hazards

Fuses and circuit breakers are designed to protect you from inadvertently overloading a circuit. When your loads demand more current than the circuit is designed to handle, the circuit breaker will trip or the fuse will blow. This prevents the conductors or wire from overheating and causing a fire. A conductor can only offer a certain amount of resistance to a current; if there’s too much current, the conductor can heat up enough to melt its insulation.
A homeowner can create a dangerous situation by replacing a fuse or a circuit breaker with one of larger amperage, thus allowing more current to flow through the wires than they can safely resist. A fire can start without tripping the breaker or blowing the fuse because the larger-amperage fuse cannot sense the problem. Some signs of a potentially overloaded system include …
➤ Thirty-amp fuses used for lighting circuits.
➤ The use of extension cords as permanent wiring.
➤ Dimming lights when appliance loads go on.
➤ Excessive use of adapters that allow more than two loads to be plugged into one receptacle.
➤ Multiple service panels and sloppy wiring practices.

Power Cords

Any cord-and-plug combination is subject to damage and wear. Lots of pulling and twisting, especially when a plug is pulled out by the cord rather than by grasping the plug itself, can cause the wires inside the insulation to break. This is particularly true with lamp cords because they use wire composed of multiple strands with a very small gauge. If the insulation protecting a cord cracks open, you could get a short circuit. It’s usually a better idea to replace these cords than to repair them.
Although it is less likely that you’ll ever have to replace a 240-volt appliance cord, these also can be changed out:

• Unplug the cord and unscrew the end that’s attached to the appliance, noting which wire (by color) went with which screw.
• Buy an exact replacement for the cord and plug.
• Connect the new cord to the terminal screws on the appliance, noting any color coding on the screws to match the individual wires (black to black, and so on).

Short Circuits

One telltale sign of a short circuit is black, smoky residue on switch or receptacle cover plates. Frayed or damaged cords and plugs also can be sources of short circuits. You need to check further for the source of the problem if your circuit goes dead and …

➤ You cannot find any visible signs of an electrical short.
➤ The circuit is not overloaded.

Before replacing the fuse or resetting the breaker, turn off all the loads and unplug everything from the receptacles. If the new fuse blows or the breaker trips right away, your problem is either in one of the devices (a switch or a receptacle) or in the wiring itself. To make sure the current is dead, remove all the cover plates and examine each device for charred wires or black residue. Clip the ends of any affected wires, strip off sufficient insulation, and install a new device. Replace the fuse or reset the breaker, and test the circuit again.
What if the circuit doesn’t short immediately after you set the breaker or replace the fuse? In that case, activate each load one at a time and then turn each one off. Check the load that eventually causes the short. The problem will be either in the fixture or appliance itself or in its wiring. Replace the offender and check the circuit again. If it still shorts out, you have a problem in the wiring itself and should call an electrician. Shorts in the wire almost always are at the device or fixture box, so the problem should be visible when you do your own inspection. Sometimes, however, the problem is caused by a splice or junction box buried in the wall and is therefore unnoticed upon first inspection. In the case of a plug-in appliance or lamp, if the circuit goes dead as soon as you insert the plug, you can assume the short is in the cord or the plug (both of which can easily be replaced). If the short doesn’t occur until after the appliance is turned on, the problem isn’t in the cord or the plug but in the appliance itself. You should then repair or replace the appliance.

Hot Electrical Equipments

The cover plate on a light switch or receptacle should not feel excessively warm and certainly should not be hot. A dimmer is an exception because dimmers dissipate the heat from dimming through the fins of the dimmer and often transfer some of that heat to the screws holding on the cover plate. Cords and plugs shouldn’t feel hot, either. Heat is a sign that the load is demanding current in excess of the ampacity of the electrical cable and/or the plug and cord attached to the load. If you replace a 60-watt light bulb with one of a larger wattage (one whose wattage exceeds the rating for the fixture), the wire or cable will still supply the current, even if doing so makes the fixture dangerous.
Heat signals that you should examine the total load on a circuit or a cord and plug.
In the case of a hot circuit, you should …

• Make sure the circuit breaker or fuse is the correct amperage for the circuit itself and the cable or wire that forms the circuit.
• Total the combined load on the circuit.
• If the load exceeds the circuit’s design, reduce the load. The real danger of an overloaded circuit is a wire heating up unseen inside your walls to the point where it can start a fire.

Electrical Warning Signs

Life is full of warning signs, but we don’t always pick up on them. A circuit that constantly burns out its fuse does not need a larger-amperage fuse. Instead, reduce some of the loads and their demand for current. Remember, electrical systems are very logical and safe when used intelligently. If you push them beyond their limits, all bets are off as to how well they’ll behave.
An orderly electrical system doesn’t overheat, start fires, or inordinately dim your lights. These are all signs that you have problems. (A fire means you’re too late.) If you have an older system that still uses fuses and does not have a grounding conductor, you need to be more observant of your usage and how your system reacts. Electrical problems sometimes require detective work. When an appliance doesn’t work at one receptacle, try it in another before you start tearing it apart. It might just be a bad receptacle or a loose terminal screw.
Remember that older, fuse-based systems weren’t designed for all the electrical loads we surround ourselves with today. These systems are safe when used judiciously.

Electrical Safety Rules

These are the basic safety rules you must remember:

• Never work on a live circuit, fixture, or device.
• Shut off power to a circuit before repairing a device or load on the circuit. Keep one arm behind your back (or otherwise away from the panel) when shutting off or turning on a circuit.
• Use a fuse puller to remove and replace fuses. Consider shutting off the power to the fuse box at the main disconnect.
• Tape over or otherwise mark a main switch, fuse socket, or circuit breaker that’s been shut off if you’re working anywhere on your electrical system. This tells others not to turn the power on. (Post a large note on the fuse box or service panel as well.)
• Always test to make sure the circuit has been shut off before doing any repairs.
• Always unplug a cord-and-plug appliance, lamp, or other similarly connected load before repairing it.
• Never stand in a puddle or on a wet surface when doing electrical repairs. Place a piece of wood on a damp floor and wear thick rubber boots to insulate your feet.

Trouble, Troubleshooting, and Safety

Residential electrical systems, especially newer installations or upgrades, usually just keep humming along. Cartoonists could depict billions of smiling, happy electrons zipping around our wires, one little electron holding hands with the next, doing our electrical bidding. But things can go bad. Bare wires can cross each other, appliances can short out, and lamp cords can become frayed. Your electrical system, unlike the institution of democracy, might not require constant vigilance, but you have to keep an eye on it. Circuit breakers that trip regularly and fuses that burn out too often are signs of a problem circuit. Dimming lights are a romantic touch when you control them with a dimmer switch but not when they dim on their own. Likewise, if your electric can opener shoots sparks like a Roman candle, it means you have a problem.
Safety should be emphasized as always, and you should pass this emphasis on to your children and anyone else living in your house. Thousands of people are electrocuted every year, many of them children, and they often require hospital care. A safe, monitored electrical system will prevent many needless injuries and possibly even deaths. Without any further lecturing, we’ll move on to scrutinize your wiring, devices, and appliances.