Ungrounded Electrical Outlets:

If your home is an older home, the electrical wiring to the outlets and fixtures in the home may not have a ground wire. One clue that your home does not have grounded outlets is if some of the outlets accept only two pronged plugs, like this one. This type of outlet is not necessarily dangerous, unless both slots are the same size. One slot should be longer than the other, as shown. If not, the outlet is not “polarized” and should be replaced. Polarized two-pronged outlets are not grounded, and should only be used for fixtures and appliances that have a two-pronged plug and do not require a ground. Use of an adapter that accepts three-pronged plugs is not recommended. Even though the tab on the adapter may be connected to the cover-plate screw, the grounding path may not be adequate. Any fixture or appliance that has a three-pronged plug requires a ground. In the past, most household fixtures and appliances did not require a ground. However, new computers and audio-video electronics usually have three pronged plugs, and have of course become very common. The need to upgrade a home from an ungrounded two-wire system to a grounded three-wire system is becoming an important consideration. If you have determined that some of the outlets are not grounded, you should also be aware that the light fixtures and switches are probably not grounded. Upgrading a home to a three wire electrical system should include all electrical fixtures and switches as well as the outlets. Since there are so many factors involved, you should have an electrician help determine just what is needed and the cost to upgrade a two wire electrical system. Since ungrounded outlets are found in older homes, it is no surprise that the outlets themselves are sometimes worn out, particularly in high use areas like the kitchen and bathrooms. When plugs fit loosely into the outlets, they may slip partially or completely out of the outlet. Outlets in this condition may overheat and become a fire hazard, especially if there is a window curtain or drape over the plug. Old, worn outlets should be replaced. A common but unwise practice is to replace two pronged ungrounded outlets with three-pronged outlets, without connecting a ground wire to the new outlet. This allows three pronged plugs to be used without adapters, but it also is ignoring the fact that the equipment plugged into the outlet remains ungrounded. It is also not obvious whether the outlet is grounded or not. Equipment plugged into the outlet may seem to work properly, but it is designed to be grounded and may become unsafe or unreliable, and often voids the warranty if it is operated without a ground. An inexpensive three-light tester that plugs into the outlet can be used to determine if three pronged outlets are actually properly grounded. A home with a two wire electrical system is not necessarily dangerous, and this is usually not a reason to avoid buying the home. However you should be aware of these limitations so you can decide if you would need to consider upgrading the electrical system. [ Back to General Home Information ] Schedule Your Inspection Today