Two Prong Receptacles Are Not as Safe as Three Prong
Do you have any old two prong outlets in your home? These have only two wires running through them: a hot wire and a neutral wire. Two prong outlets are not grounded, which can leave you unprotected from stray currents and result in electrocution or a power surge through sensitive electronics, often destroying them in the process.
Three prong outlets feature a third grounding wire, which gives energy surges somewhere to go other than into your body or electrical equipment. This feature has been the standard for a while now, but if you live in a home built before the 1960s and you haven’t addressed the wiring, odds are you still have two prong outlets throughout your home.
Can You Keep Two Prong Outlets?
The National Electrical Code allows you to replace an existing two prong outlet with another one like it when no grounding wire is present in the circuit powering that outlet. This means if you must replace a faulty two prong receptacle, you aren’t breaking any codes if you choose not to upgrade.
Where Three Prong Outlets are a Must
Modern sensitive electronics come with three prongs for a reason. Anywhere you plug in computers, TVs, window air conditioners, vacuum cleaners, and other appliances or electronics with three prongs, you need a three prong outlet. All outlets in your kitchen, for example, should be three prong outlets.
Perhaps you think plugging devices into a surge protector, which you then plug into a “cheater” three-to-two prong adaptor to fit the old fashioned outlet, is the way to go. However, this does you no good at all. The fact remains that two prong outlets have no ground and therefore don’t benefit from surge protectors.
Simply swapping out two prong outlets for three prong versions isn’t enough, either. In fact, this creates an electrocution and appliance hazard.
Getting Your Outlets up to Code
You have four safe options for getting your outlets up to code.
Replace with Another Two Prong Outlet
As discussed earlier, you can replace an existing two prong outlet with another like it without breaking electrical codes. This is the riskiest option however, since it leaves you unprotected.
Replace with a GFCI
A better, though still not perfect, solution is to upgrade your outlets to a ground fault circuit interrupter, or GFCI. According to the National Electrical Code, the outlet must be tamper-resistant if installed 5.5 feet above the floor or lower and you must label the outlet as “GFCI protected” and “no equipment ground.”
You may need to replace the outlet box to accommodate a larger GFCI receptacle. A GFCI installed in this way is not grounded, so while this option prevents shock-related issues associated with two prong outlets, it provides no ground protection for sensitive electronics.
Retrofit a Three Prong Receptacle Without Rewiring
Metal boxes found in most old outlets are attached to an armored cable, which serve the same purpose as a ground wire. You can take advantage of this to ground the receptacle without rewiring.
First, test for a grounded box with a circuit tester. Insert one prong into the shorter hot slot and touch the other prong to a cover plate screw. If the circuit tester lights up, the box is grounded. You now know an electrician can inexpensively ground the receptacle without rewiring it.
Rewire the Panel
If a circuit test reveals that the box is not grounded, hire an electrician to rewire the panel with a three-wire circuit to provide the necessary ground. This is the best way to ensure your family and electronics are protected from stray currents that can cause electrocution and power surges.