Reverse Polarity Dangers: Ways To Test & Repair
When you get shocked by an appliance you thought worked correctly it can be startling or downright scary. This shock is reverse polarity, and it can be a very serious potential problem. It damages electronics and can even cause severe electric shock. This problem is fixable. There are even simple ways to test for it.
Reverse polarity is caused “hot” and “neutral” wires are crossed. This crossing results in a potentially dangerous reversed electrical flow. You should test all electrical outlets for reverse polarity using an outlet tester. You must locate where the wires were crossed in order to restore correct polarity. Be sure to consult an electrician to repair the problem unless you are versed in electric repairs.
It is important to understand normal electrical polarity in order to understand the hazards of reversed polarity.
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Electrical Polarity and Why It Matters
Electrical polarity in the household refers to energy and its flow through electrical wires. Electricity flows from one wire into your device and then out through another wire. Your home has two types of wires that control electrical polarity. There is a white “neutral” wire, and a black or sometimes red “hot” wire.
Electricity normally flows through the “hot” wire. Energy then enters the device from the “hot” wire and stops at the device’s on/off switch. Electricity cycles through an appliance when the device turns on. The electricity then exits the device and enters into the “neutral” wire.
When your electric wiring is installed properly there is a steady and safe flow of electricity. The energy moves through the “hot” wires and returns to the “neutral” wires. There are potential problems if wiring is installed wrong. You may not notice many of these problems until it is too late.
What Happens When You Reverse Polarity?
When you reverse polarity, the flow of electricity switches in the wires. Electricity enters through the “neutral” terminal instead of the on/off switch when polarity is reversed. This change in energy flow often causes the connected appliance to remain electrified at all times.
What Causes Reverse Polarity?
Reverse polarity is caused when a white or “neutral” wire goes where a black or red “hot” wire should go, and vice versa. In other words, the wires are switched.
Unprofessional electrical work is often the culprit when you find reverse polarity in your home. Reversed polarization and questionable electrical work often go hand in hand. Polarity is reversed when wires are connected in the wrong spots. This can only be done when someone incorrectly connects wires.
Is Reverse Polarity Damaging
Most newer devices have mechanisms that help protect against reverse polarity. However, reverse polarity can still hurt your appliances. Your unprotected appliances will turn on and off normally but they can still suffer damage in several ways.
Appliances Overheating
An appliance can be electronically active the entire time when you plug it into a reverse polarized outlet. This constant electric charge causes the device to run hot. Devices overheat when they never have a chance to charge down. Many electronics are damaged or broken if they overheat for too long.
Devices Deteriorating Faster Than Normal
Leaving unprotected electronics plugged into an outlet with reverse polarity can wear them out fast. When you plug an appliance into a reverse polarized outlet it is like leaving it on constantly. Many devices last much longer when they are turned off. When an appliance is affected by reverse polarity it has no idle mode. A device may only last a fraction of the time it could have.
Damaged Batteries And Chargers
When you plug an unprotected charger into an outlet and see your device is charging, you may think it functions properly. If the outlet you plugged your device into has reversed polarity, the charger and the battery itself may actually suffer permanent damage.
Is Reverse Polarity Dangerous
The most troubling aspect of reverse polarity is that it often goes undetected until an issue arises.
Electrical Shock
Electrical shock is a major concern when it comes to reverse polarity. A device can become “live” even when it appears to be off.
A butter knife in a toaster is a popular analogy that shows why this is dangerous. There should be no electrical charge running through a toaster when it is off when a toaster has normal polarity. If you reverse the polarity the current will be live. This means if you use a knife to free up a piece of toast the electricity can run through your body and potentially stop your heart.
Fire
In addition to reverse polarization causing bodily harm, it can also create sparks and fire. An appliance can short circuit or spark if it is plugged into an outlet with reverse polarity. If this appliance is near anything flammable it can catch fire. This can destroy an entire home.
How Can you Test For Reverse Polarity
- Purchase an outlet tester. There are a variety of outlet testers on the market. Choose an outlet tester with a voltage chart. You can easily identify electrical outlet issues with an outlet chart.
- Plug your outlet tester into the outlet you want to test. Make sure the number of prongs on the tester matches the number of prongs on the outlet you plan to test. Wait a few moments for the outlet tester to register the electricity.
- The outlet tester will light up. Notice the light pattern that appears on the outlet tester. Its light pattern will correspond to the outlet’s health.
Note: Different polarity testers may use slightly different light signals to signify an issue. Always refer to your specific tester chart when you diagnose an outlet.
Check Other Outlets
Use an outlet tester on other outlets throughout the property. This ensures the tester communicates properly. This also confirms the other outlets are safe.
How Can You repair Reverse Polarity
To repair an outlet with reverse polarity you must find the location where “hot” and “neutral” wires were crossed during installation. You must keep in mind the wires were almost certainly crossed due to poor electrical work.
Therefore, there is a good chance there is more unprofessional electrical work behind the walls. You may have a very hazardous electrical system that can span all the way to the circuit board. Unless you are certain of the safety involved in the work you are performing, it is best to call a professional.
Consider An Electrician
An electrician can diagnose, repair and prevent future reverse polarity issues. Yes, hiring an electrician is more expensive than repairing it yourself. However, it is certainly safer. Hiring an electrician should ensure you that electrical system is secure and free of hazards.
Repairing Polarity On Your Own
There are several steps you can take to resolve reverse polarity if you are comfortable with electricity. It is important to understand the dangers involved when you perform your own electrical repairs.
1. Shut Down Circuit Breaker
Identify the circuit breaker that controls the outlet or outlets with reverse polarity. Turn it off completely.
Safety Tip: Use the outlet tester to confirm the power is off.
2. Remove the Outlet Cover Plate
Unscrew the screws and remove the cover plate. This reveals the outlet parts and the wires connected to it.
3. Locate the “Hot” and “Neutral” Wires
Consult an electrician if for any reason you can not distinguish the difference between the “hot” and “neutral” wires.
4. Find The Source of the Problem
The lines can cross in several locations. Be sure to find the exact location in need of repair.
- Check The Outlet Connections. The outlet connector is one common location for crossed wiring. An amateur will often attempt to swap outlets but neglect to reconnect the wiring correctly. Confirm the “hot” and “neutral” wires are connected in the proper locations.
Note: The “hot” wire should be connected to the brass screw, and the “neutral” wire should be connected to the silver screw. If the “hot” wire is connected to the silver screw this will cause reverse polarity and vice versa.
- Check Junction Boxes. A junction box is a protected enclosure where multiple wires from behind your walls meet and also connect. These boxes should be located in an accessible location. Ensure the wire connections in the junction box are correct. The “hot” wires should connect with the “hot” and the “neutral” with “neutral”.
Note: There can be multiple junction boxes for one set of wires. Confirm you checked all junction boxes corresponding to the wires with reverse polarity.
- Check the Circuit Board. The wires can be crossed at the circuit board as well. This is not common. Check the wiring at the circuit board to confirm it is correct.
5. Turn the Circuit Breaker Back On.
It is safe to restore power once you locate the crossed wire and connect all wires in the correct locations.
6. Test Outlet’s Polarity.
Check the polarity of the outlet or outlets in question using an outlet test. There should be a correct polarity if everything was reconnected properly.
How Do You Prevent Reverse Polarity?
Ensure there has been a proper home inspection when you move into a new home. You should make sure the work is tested and done professionally when any electrical repairs are performed on your house.
Note: Some older plugs may not have the small and large three or two prong plugs. Most electricians advise replacing devices that do not have a large and small prong input. These outlets are outdated and do not enforce correct polarity.
Replace Outlets
It is a good idea to periodically replace your electrical outlets. Many older houses have outdated outlets. Replace any outlets that have only two prong inputs.
You may get frustrated when you struggle to plug a charger into an outlet in the dark. This might make you wonder why one prong of a plug is bigger than the other. The three prong design allows only one way to plug in a device. This unique design also promotes correct polarity.
The larger prong should link to the “hot” wire. The smaller prong should link to the “neutral” wire. The bottom prong is called a grounding prong. This design forces you to plug a device in without adjusting electrical flow.
Buy An Outlet Tester
An outlet tester is a great addition to your tool arsenal. They are also inexpensive. Outlet testers check for several electrical issues in outlets. You can save you a lot of money and worry in the long run when you use an outlet tester. Testing is especially important after you have any electrical work done.
Related Questions
What Is The Safest Kind of Electrical Outlet?
There are two top electrical outlets on the market today. One type is the Ground Fault Circuit Interrupter (GFCI) style. The other style is the Tamper-Resistant (TR) outlet. Both of these outlets types are easy to instal in your home. These electrical outlets also help prevent electrical shock.
What Is reverse Polarity On A Car Battery?
Your car battery can reverse its polarity. Reverse polarity can occur if the battery is dead and jumper cables are connected in a reverse fashion. A car battery can reverse its polarity after several seconds of an improper connection. This may damage much of its inner electronic properties. It can also damage several computer-based parts within the vehicle itself.
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The Bottom Line
Reverse polarity can be a serious issue. It is often overlooked until an issue arises. Do not wait until an appliance is damaged or shocks you before you resolve this problem.
You can fix an outlet with reverse polarity yourself. If you do this please remember that is dangerous to work with electrical wires. Unless you are familiar and comfortable with this type of electrical repair it is best to consult an electrician.
Any house that experienced some unprofessional electrical work is subject to reverse polarity. Do not cut corners when it comes to electrical work. This is best way to avoid future reverse polarity issues in the home. Be sure to test outlets once all work is complete.
Tom Gaffey is an expert writer who currently resides in Washington D.C. Tom has a passion for real estate and home improvement writing, as well as travel and lifestyle writing. He lived the last twelve years in Hawaii where he worked closely with luxury resorts and event planners, mastering his knowledge of aesthetics and luxury products. This is where he found his passion for home improvement and a keen interest in DIY projects. Currently, Tom resides in Washington D.C, and also working on his debut fiction novel.
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