One item that you will usually not find a shortage of in modern homes is electrical receptacles or more commonly known as electrical outlets. Outlets help power all your household plugin fixtures and appliances. Just with any electrical component of the fixture, proper wiring of outlets is essential for your family’s safety. In this article, we will talk about the five main ways an outlet can be miswired and why each can be hazardous, but before we do this, let us talk a little bit about the proper wiring of an electrical receptacle.
How an Outlet is Properly Wired
Before I get started, I will warn this is a dumbed-down version of how to wire an outlet. There are several different scenarios where there are multiple outlets and fixtures on a circuit requiring slight variation in the wiring. In simple terms, the hot wire, neutral wire, and ground wires must all attach to the right screws on the outlet. For those without much electrical background, here is a breakdown of what each wire does.
a. Hot Wire – Carries the electrical power from the source, which is usually the main electrical panel for the home. These wires are typically color-coded black (occasionally red) and need a return path (see neutral wire below to allow for the flow of electricity.
b. Neutral Wire – Carries electricity back to the power source and completes the power circuit. In an outlet, the hot and neutral lines are not connected until an appliance is plugged in. When a plug engages the outlet, it allows the electricity to flow from the hot wire through the appliance and the neutral wire.
c. Ground Wire – The ground wire is there as an electrical safety net. Grounding provides an alternative path for electricity to flow through instead of electrocuting an inhabitant. Appliances have internal grounds that connect to the outlet, so if the wiring of the appliance loses and causes a short, you are protected from shock.
If you are completely confused by what I am talking about above, hopefully, you will find the below diagram helpful:
Now that we understand a little better how an outlet is wired; let’s talk about the different ways it can be miswired.
Different Ways an Outlet can be Mis-Wired
1) Open Ground – As we discussed above, grounding is a safety feature. Suppose you live in an old home and see a two-prong outlet that is a receptacle without a ground as it was installed before grounding was required by code. A three-prong outlet can also be considered ungrounded if the ground terminal is found to be open (wire not connected to the ground terminal).
The safety issue with an open ground is pretty simple, your appliance will not be grounded, and if electrical wiring becomes loose, there is a potential for electrical shock. For a three-pronged outlet, the fix is simple, securely connect the ground connection to the screw terminal. For a two-pronged outlet, you will need to replace the outlet itself and then properly wire it.
2) Open Neutral – Like an open ground, an outlet with an open neutral has no wire connected to the neutral terminal screw (or has a loose wire connection). As you might deduce from reading about the purpose of the neutral wire above, if the neutral wire is not connected, you would assume there would be no power to the outlet. While that may be true the voltage of the outlet can actually increase to 240V if a neutral is shared between two circuits. The result is a power surge and your appliances breaking. The fix is most likely just re-connecting the neutral wire, but if you don’t understand the inner working of an electrical circuit, it is best to hire a qualified professional only in case.
3) Open Hot – If you have been following along, then you have probably figured out an open hot is an outlet that has no wire connected to the hot terminal screw (or has a loose wire connection). This will result in the outlet not working. The real concern is that there may be a live wire that is not connected behind the outlet, which is a potential arcing and fire hazard. Once again, the fix usually is as re-connecting the hot wire, but make sure you turn off the outlet breaker before removing it; otherwise, there can we a live wire waiting to spark or electrocute you.
4) Hot-Neutral Reversed (also called Reversed Polarity) – This occurs when the hot and neutral wires are placed on the wrong terminals (Hot Wire connected to Neutral Terminal, Neutral Wire connected to the Hot Terminal). The biggest issue with this type of miswired arrangement is that when something is plugged in, there usually are switches that disconnect the hot side since the neutral side is not live when the power is cut. Now that the two are reversed, some components may still be energized even when switched off. As an example, if you flip the switch off on a kitchen appliance and try to unjam something from a blender or toaster, there is a good chance that you could come in contact with a part that is energized due to reverse wiring. This is an electrocution hazard, and the issue should be fixed for your safety.
5) Hot-Ground Reversed – This configuration is just like the reverse polarity case except with the Hot and Neutral wires and terminals. This is a very rare configuration, and even if the outlet is wired this way, there are other things that need to happen for electricity to flow from the ground connection in the outlet. If your tester reads this configuration, then it should be evaluated by a licensed electrician to confirm what corrections need to be made.
How to Tell if Your Outlet is Miswired
You may be thinking all of this information is great, but how can I tell is my outlets are miswired. Well, if you just bought your property and had an inspection, your inspector should be able to say to you. But if not, all you need to do it buy a circuit tester like the one shown below. There are a lot of versions that cost less than $10 bucks and will do the trick.
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