Electrical & Electric

Extension Cords and Electrical Plugs

We all use extension cords and electrical plugs in our home. Unfortunately the electrical cords on most electrical appliances are too short to reach the nearest electrical outlet. One would think that they would have at least an eight foot cord because the electrical code requirement is to place electrical outlets no further than eight feet from each other. In addition we use extension cords in the garage and workshop to operate electrical equipment. There are several different types of plugs on these extension cords which poses problems plugging them in to appliances.

For the most part the electrical plug types of the world are divided into two major geographic areas. The U.S. and Japan in one group, and South America, Europe and Asia in the other group. Africa, southern Asia, and Australia are another group where they use a very heterogeneous mix of electrical plug types.

In the US the two types of electrical plugs used are the Type-A and Type-B. The most prominent plug used on lamps is the Type -A plug which is a two pin ungrounded plug.  The second is a Type-B plug which is a version of the Type-A plug. The Type-B plug is a three pin plug that incorporates a ground pin.

The Type A has 2 flat parallel pins. These 2 pins used to be the same size, but on new electrical plugs the neutral contact is larger than the live contact.

The Type-B electrical plug has the same 2 parallel pins as the Type-A electrical plug, but also has a round grounding pin beneath the two flat pins. The grounding pin is longer than the flat pins. That's so the electrical plug will be grounded before it makes the connection to the electrical supply.

Since about the mid-1960s, all electrical outlets and appliances are required to accommodate the Type-B 3-pin electrical plug design. But most lamps are not required to have a three pin plug although they do fit into a three pin outlet.

Unfortunately extension cords last for many years and if you have an older cord that does not have a three pin plug it will not work on newer electrical appliances because there is no place for the ground pin. Many users simply use an adapter that adapts the three pin appliance to the two pin cord. This is potentially a dangerous situation. The purpose of the third pin, the ground pin, is to protect the users in the event the appliance has a short circuit. If the appliance shorts out, the user can suffer from a severe burn or electric shock.  

There is no way that we can get away from using extension cords and electrical plugs in our home but we can insure that we use them safely. Never cut the ground pin off an electrical appliance so it will fit into a two pin extension cord. Use an adapter if necessary. If you make your own extension cords out of stock material insure that you always use a three pin connector on both ends. A proper extension cord plug should always have three pin connectors.

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