Choosing the right extension cord

Congratulations on that new air conditioner you just bought. It ought to help you get through the dog days of August.

That is, if you use the right connection to an electrical outlet. Often such outlets are not positioned near the window. The answer is an electrical extension cord. But not just any old wire you've got lying in the garage. The cord that was good enough for the table lamp won't make it for an air conditioner.

The U.S. Consumer Product Safety Commission estimates that about 4,700 residential fires originate in extension cords each year, killing 50 people and injuring some 280 others. You don't want to be part of that statistic.

Here are some questions and answers from Underwriters Laboratories Inc. on extension cord safety:

What size cord do I need?

To determine what size - or gauge - cord you will need, you will also have to determine how long you need the cord to be. A cord, based on its gauge, can power an appliance of a certain wattage only at specific distances.

As the cord gets longer, the current carrying capacity of the cord gets lower. For example, a 16-gauge extension cord less than 50 feet in length can power a 1,625-watt appliance. A 16-gauge cord that is longer than 50 feet in length can only power an appliance up to 1,250 watts.

The larger the wire, the smaller the number. For example, a 12-gauge wire would be larger, and can power larger wattage appliances, than a 14-gauge wire.

All appliances indicate how much wattage is consumed when operated; that rating can be found on the appliance itself. Other appliances will indicate power usage in amps. Quick tip: If your appliance indicates that it uses 5 amps at 125 volts, then its wattage rating is 625 watts (5x125).

How about plugging two appliances into a single cord?

If you are going to use the extension cord with two or more appliances, you must add together the wattage rating for all appliances used on the cord. The total of those wattage ratings will help you determine which gauge size you will need.

Any storage problems with extension cords when not in use?

Store all cords indoors when not in use. Outdoor conditions can deteriorate a cord over time. When storing cords try to wind them in neat loops without kinks.

Can I leave an extension cord plugged in when not connected to an appliance?

Never ever keep an extension cord plugged in when not in use. The cord will still conduct electricity until it is unplugged and can create safety conditions when tangled about on the floor or rug.

How can I keep my children from playing with electrical outlets?

Most newer, indoor cords with more than one outlet have covers for the unused openings - use them. Children and pets face serious injury if they chew on unused outlets or stick sharp metal objects into the openings.

When should extension cords be replaced?

Visually inspect extension cords often. Do not use extension cords that are cut or damaged. Touching even a single exposed strand of wire can give you an electric shock or burn.

Some of our home's electrical outlets are old and don't have holes for modern, wider thee-pin extension cords? Can I file the blades down to fit he outlets?

Never file or cut the plug blades or grounding pin of an extension cord or appliance to plug it into an old outlet. The wider blade assures that the circuit you create will be safe, and removing the round grounding blade removed shock protection.

As a safety feature, extension cords and most appliances have polarized plugs (one blade wider than the other). These special plugs are designed to prevent electric shock by properly aligning circuit conductors. If a plug does not fit, have a qualified electrician install a new outlet.

- Contact reporter Sam Bauman at sbauman@nevadaappeal.com or 881-1236.