Current wiring standards are put in place to keep occupants safe. When the wiring in a home as been done by, let’s say Uncle Jerry, the potential for fire and electrocution hazards go up. All components are necessary, from the actual connections, to the boxes that protect the user and the connections from damage and sparks. In the following paragraphs, we’ll talk about some issues that we may see on a routine home inspection.
Receptacles with two slots.
Other than being outdated, there is actually nothing wrong with this type of a receptacle in a home. It does indicate that the branch circuits in the home are most likely outdated and in need of an upgrade at some point. This type of receptacle would increase the likelihood of the end user connecting a 3 prong adapter to use a 3 prong device or a power strip. If a power strip is used in combination with the adapter, just keep in mind that the circuit does not provide any protection in regard to grounding our surge suppression.
Installing a 3 prong receptacle on a 2 conductor circuit.
This is a common defect in old houses, and sometimes at newer homes when someone wants to give the “effect” of an updated electrical system. An ungrounded three-prong outlet increases the potential for shocks or electrocution, and prevents surge protectors from doing their job, which may allow for damage to electronic components. In this situation, the following solutions are recommended.
- Remove the 3 prong receptacle and install a two-prong receptacle.
- Install a GFCI receptacle. A GFCI receptacle will help solve an electrocution hazard, but it won’t allow surge protectors do their job. A sticker needs to be applied to the face of the GFCI outlet that says “No Equipment Ground”.
- Install a standard three-prong outlet and add GFCI protection at the panel, the outlet or somewhere in between. Labels need to be applied to the outlet that say “GFCI Protected” and “No Equipment Ground”.
Receptacles with reverse polarity or where the hot conductor is wired to the large slot and the neutral conductor is wired to the small slot. When the circuit is wired correct, the only conductor that is live or carries voltage when the circuit is off is on side of the power cord going to the wall. If the wiring is reversed, now the whole appliance is constantly energized. Outlet polarity is a safety issue that needs to be corrected. It may not be as easy as reversing the wires at the outlet because the problem may be further upstream behind the wall. Let’s say a person was changing a light bulb on a lamp plugged into a reversed circuit. That person could be shocked if they happen to touch the threads of the bulb.
False or “Bootleg Grounds”
This is a real safety hazard. This is where someone who possesses electrical knowledge but does not care about the safety of the occupants or future buyers of the home. The installer connects a wire from the ground screw to the neutral connection. This type of wiring will fool most inexpensive testers and a “correct” reading will be displayed. A more expensive circuit analyzer is needed to detect this type of connection. The real issue here is that when an appliance with a 3-prong plug is inserted into the receptacle, one of the conductors is connected to the body of the appliance. Let’s say the person holding the appliance also touches something that provides a parallel return path… well now the current flows through that person causing an electrical shock or death. This condition can be even worse if the receptacle is also wired with the polarity reversed. In this case, the live wire is connected to 120-volts and ground. The cheap tester says everything is connected proeperly but the body of the appliance now carries 120 volts!!