Reverse Polarity RV Surge Protector: What Is It & How to Fix?

reverse polarity RV surge protector

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Nothing feels better for campers than going to campsites with your luxury RV and having some fun. But this fun only lasts until you plug your coach into a pedestal only to find an annoying message on the surge protector.

“Reverse Polarity”.

You keep going to different sites and find the same error every time. If this is your first time discovering this problem and you don’t even know what reverse polarity is, don’t worry.

This guide will let you know everything you need to know about reverse polarity showing on your RV surge protector and how to fix this issue.

Let’s get started.

What is Reverse Polarity?

Reverse Polarity, also known as the hot neutral reverse, is when the hot conductor and the neutral conductor are connected reversely in an electrical connection. If you find the black (or red) hot wire connected to a silver screw and the white neutral wire connected to a gold screw, this means that your outlet has reverse polarity.

When the wires are connected in this erroneous way, you will measure 120 volts between the hot and neutral conductors, as opposed to 0 volts had they been wired correctly.

Reverse polarity is a common mistake many electricians commit when doing electrical work. This is also true for campgrounds. Campground owners may sometimes hire unprofessional electricians to get the job done for cheap. But they get the wrong result.

Why is My RV Surge Protector Showing Reverse Polarity?

The basic reason why a reverse polarity can happen in an outlet remains the same as we discussed above. However, if your RV’s surge protector is showing reverse polarity, there might be a few scenarios you need to consider.

Some common reasons why your RV surge protector is showing reverse polarity include –

  • The pedestal where you’re plugging in your cords is wired incorrectly.
  • The adapter you’re using is faulty due to reverse wiring.
  • The surge protector is giving a false reading. This can happen especially if you’re using it with a 15 amp to 30 amp adapter.
  • Another reason can be floating ground. No ground connection can cause the surge protector to show a reverse polarity error.

Is Reverse Polarity Dangerous For Your RV?

The short answer is yes. Reverse polarity is an electrical connectivity problem. It can cause serious issues for both your RV appliances and more importantly, yourself. If the hot wire and neutral wire aren’t connected as they are supposed to, this can result in the neutral conductor containing 0 volts while the hot one staying at 120 volts. This hot high-voltage line is responsible for powering the equipment in your RV. 

When the connection is established correctly, the remaining voltages on the appliances are pulled towards the neutral connection at 0 volts. This removes the possibility of any shock hazard on the exposed parts.

For reverse polarity, there are 120 volts on the neutral conductor. So the stray voltages will travel towards 120 volts, creating shock hazards inside the RV if you touch both the appliance and the ground.

However, since the neutral and ground remain separate inside the RV, most things still work when the polarity is reversed. Some components might be polarity sensitive. These appliances are not smart enough to verify the input power polarity. They may not even work.

How To Test Reverse Polarity

You can test Reverse Polarity through a few methods.


One way is to take a voltmeter and put it between the ground and neutral terminals. Check if the voltmeter outputs 0V voltage or not. You can repeat this process using the hot terminal as well.

Put the voltmeter between the ground and hot terminals. Observe the voltmeter and see if the voltage is at 120V or not.

If you got the correct voltage both times, this means the polarity is normal and you’re good to go. The reason for double-checking is to be very careful you didn’t make any mistakes the first time. If you have gotten the appropriate voltage both times, you don’t need to worry about reverse polarity.


Another easier method is to use a 30 amp to 15 amp dogbone adapter and combine it with a 3 light outlet/receptacle tester. Plug in the outlet tester and see the lights. If you see the red light on the left and the yellow light in the middle litten up, this means there is reverse polarity on the outlet.

Although, the lighting pattern may be different for different tester models. Make sure to read the manual. A lot of testers also have lighting patterns drawn on their bodies.

How To Fix the Reverse Polarity Problem of Your RV Surge Protector

Now that you have a clear idea about the reverse polarity issue you see on the surge protector, here are some fixes you can apply:

  • Test the outlet for reverse polarity: If it does have wrong wiring, get it fixed by an electrician. If it’s in a campground, let the authority know. If it’s in your own home, hire an electrician or follow this guide to fix it.
  • Use a polarity adapter: If you can’t buy one, you can make one yourself. Check out this Instructable guide.
  • Check and test your adapter: Use a different adapter for the connection. If it works on the same outlet, this means you need to change your adapter.
  • Try plugging surge protector: Sometimes surge guards can show wrong readings for no reason. Disconnect them and connect them again to see if the problem is resolved.

Final Words

Reverse polarity on your RV’s surge protector can be a daunting issue. It’s annoying because you’re unable to charge your RV. Worst case scenario, it may even electrocute you. We are saying this so that you don’t take this matter lightly.

If you notice reverse polarity in an RV park, make sure to let the authorities know about it. Apply the fixes we’ve mentioned above and have a safe trip.

Palash is an entrepreneur in the tech industry and the author of the Smart Home Protector. As a tech entrepreneur & reviewer of a home safety gadget store, his job helps customers remain on top of what's coming next in our rapidly changing world.

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