How To Protect Your RV Electrical! RV Surge Protectors

Understanding RV electrical is important to protect your RV and also for your safety. Plugging in an RV is such a normal thing we do, and take for granted, but there are some important things we need to check and watch out for. With a few tools and knowledge we can protect us and our RV from mis-wired pedestals, low voltage, surges, “hot skins” and more. 

Let’s start simple, with the simple things we can do and work our way to the bigger topics of the types and uses of RV surge protectors. First thing is to understand the weakness of the plug of the RV electric cord connection and why we see so many melted power cords especially on the 30 amp RVs. Oftentimes where we plug into the pedestal for the RV will be our weakest link. Another problem is you don’t have to look far to find a loose outlet in an RV park. If you find a loose outlet where it doesn’t feel like your cord is making good connection or it doesn’t even want to stay plugged in, you should let the staff at the campground know to see if they can swap it out. The problem with a loose connection is it’s not making enough of a connection in the electrical plug and will generate heat the more you try to use power. The heat will buildup and melt the cord and sometimes weld the contacts together. That is a bad situation which could be moments away from a fire. 

A loose outlet isn’t the only contributing factor to a weak connection, there can be loose screws in the plug or the plug contacts could be oxidized. Here is what we can do on our end since we can’t go around changing RV pedestal plugs at campgrounds and RV Parks. 

  1. We can make sure our screws in the plug end are tight and not stripped out on our own cable.

  2. We could clean the metal on the cable ends. We can use something like DeoxIT or even White Vinegar to clean the corrosion and protect it with Dielectric Grease or some even use CRC 05074. This will help protect it and give us a good connection on our end. 

  3. A very simple practice we can have is to turn the breaker off before we plug in our RV/RV Surge protector. It not only is safer it is better for the equipment and no sparks will be adding to the damage of the plug and pedestal.

Testing The Electrical Connection

Plugging in our RV is such a common practice, we take it for-granted. There are some really fast tests we can do to see if it is safe to connect our RV. This is where we see our first benefit to having a surge protector for our RV and we will go look at many options that are out there. On almost all RV Surge Protectors out there we have some information displayed on it when we plug it into the RV pedestal  or outlet. I recommend if you have a portable surge protector to plug it in and turn on the breaker to see what possible problems you have before connecting the RV. Most of them will tell you

1. Reverse Polarity (50 amp each leg)   2. Open Ground   3. Open Neutral

Which is a great place to start to see if it is wired correctly. If you would rather do more tests and test it out yourself you can get an electrical test kit. I’ll show you how to do additional testing after we look at the options we have for EMS and Surge protectors. 

The typical surge protector is a great tool for quickly showing you if the pedestal is wired correctly at first glance but does no other function automatically other than protect your RV from the event of a surge. On the other hand an EMS Devise is going to actively look for problems as well as surges and disconnect your RV if it needs to, to protect the RV.  So if you have an open neutral or low voltage it will turn off the supply of power to the RV until you can correct the problem. We currently have the Progressive Industries hardwired unit. I went with this one because it was not as expensive as the others, I liked the hardwire connection for the quality of the connection and I liked that it is out of sight and out of mind for theft. One of the biggest advantage of using with an EMS device is it now actively protects you from low voltage. Low voltage is really bad for things like your AC on your RV and other electronics. An EMS device will disconnect the RV when the voltage drops too low. An EMS is great for this because you can check the voltage at one time and be fine but it doesn’t take long to change. One of the most common times we see low voltage is in RV Parks with poor electrical setups and or when it gets hot our side and every one in the RV Park is turning on their AC units to cool the RV. With that much draw on the park the Voltage can drop causing RVs to draw more amps while causing damage to AC units, generating a lot of heat which is what we want to avoid. An EMS will monitor the voltage and shut off the power if it drops below 104 Volts protecting your equipment. So the difference between a common surge protector and an EMS is an EMS will actively monitor the input looking for problems and disconnect your RV if a problem is detected. 

An EMS can be bypassed depending on the unit you buy. For instance if you installed a hardwired EMS and you plugged into an inverter generator it would block the power because it would be detecting the floating neutral. In this situation it isn’t really a problem but the EMS will block the power and you can either bypass the EMS or you can make or buy a ground neutral bond plug. When you plug into a pedestal this bond is already made but on an inverter generator it isn’t necessary. The plug is extremely simple to make but you must do it correctly. All you have to do is in a standard plug connect the neutral terminal to the ground terminal. Be extremely careful not to accidentally connect it to the hot terminal, nothing will be connected to the hot terminal. I would recommend double and triple checking to make sure you wire it properly and if you don’t feel comfortable making one they are available to buy. So instead of bypassing the EMS you can use this plug in the generator and it will register with the EMS properly.

Now if you are not a fan of having your power shutoff in low voltage situations there is a highly controversial device called the AutoFormer. The way this works is it monitors the voltage coming in and will boost the voltage by converting the available Amps to Volts. When the voltage drops to 113v-90v it will boost it 10%. They also have surge protection built into them as well as indicator lights to show if the pedestal is wired properly. To be completely honest this has come under fire and in some areas and parks are not allowed to be used and where the 2020 NEC code is adopted. The idea sound great, I can keep my power on in parks where the voltage is too low damaging my equipment or shut off by my EMS. The problem is in a park or campground where there is bad voltage, it probably means it has inadequate wiring and additional stress is not what it needs. The reason an autotransformer/Autoformer would be adding stress is everything is working well in your RV so you tend to use more power, not to mention that the device itself is using more amps to converter the amps to volts. Yes it’s true if you run your AC at a lower voltage it will pull more amps by itself and it will not be running well, it will have decreased efficiency, and the components will be producing more heat than normal.  In a nut shell the idea behind banning the Autoformer is, the more people use them and the more people use power the more the voltage drops and the more it puts a strain on inadequate wires in the campground potentially creating a dangerous situation on the entire system. Here is my 2 cents and a tip on how we use ours where allowed. Instead of parks and the NEC banning it I think it should be encouraged to use them while limiting how much electricity you are able to use. This could be done by installing lower amperage breakers on the pedestal or even the idea of an approved device that limits (ie. Autoformer with a 20 or 25 amp breaker on the input side) how many amps can be used. It could be how the Autotransformers are made for the user to purchase or an additional device supplied by the user inline before the Autotransformer. Campgrounds don’t usually factor in the park being full and every RV using multiple AC units especially in the older parks that were built before RVs were as large as they are now and as many devices as they do today. The way we use ours, where they are still allowed, is I self regulate how much power we use when we use it, staying under 15 amps at maximum draw. I don’t want to add strain on the system and I don’t want to use a lot causing the voltage to drop even lower for RVers around me. 

That is just my opinion of the use and ban of the autotransformer. I would rather come up with a solution that is better for RVers and sustainable for parks at no additional cost needed for RV parks. The cost can land on those that want to use an Autotransformer and have the option to use limited power at better voltage for their RV. I don’t care for the way it has been labeled “stealing” power as you are still staying within the limit of the site you paid for and the breaker regulating what you can use. Yes it uses more amperage to increase the voltage in the relationship of volts x amps = watts, but the point is you are not stealing anything you have not signed up for or paid for. 

Our plan for protecting our RV, I will admit is a bit over the top, is to use a portable surge protector at the pedestal, it gives us a layer of surge protection to begin with and the ability to see at first glance if the outlet is wired properly. Second we have the EMS installed on the RV itself to actively monitor and disconnect  if an issue comes up. last on our list is the Autoformer we occasionally use as needed and use it in place as our surge protector at the pedestal and try to lock it when used. The Autoformer goes before the EMS in any setup like this.

Last on our list is additional steps we can take to be safe and check the connection farther. First and most simple to check if you have a “Hot Skin” on the RV. That means you can be shocked by your RV which is to be taken serious and disconnected immediately so you can fix the cause. A simple non contact voltage tester can be used to see if there is voltage running through your RV frame and really the entire unit. It’s good to get one that can test close to 40 volts and just turn it on and touch the steps of your RV. If it alerts to voltage do not touch the RV but disconnect it from power. If you would like to test the outlet it is actually fairly simple and fast to check. On the 30 amp side you can use an adapter and an outlet tester to see if it is wired properly. Also if you would like to test the voltage and if the 30 amp plug is wired properly you can use a multimeter to test the voltage between terminals and if it is wired correctly you should see the voltages like you see in these diagrams. If on a 50 amp receptacle you see 0 volts between the L1 and L2 that means they campground bootlegged or basically used the same wire for both L1 and L2. this is extremely bad because your Neutral wire will try to carry the load of everything the RV is using on both L1 and L2 and as that goes up to and over 50 amps it will heat that wire up and potentially start a fire and more than likely melt whats around it. When you measure a proper 240 between  L1 and L2 it means they are on a split phase so if you are using 30 amps on L1 and 20 amps on L2 that leaves 10 amps to be on the neutral. L1 and L2 will for a simple way of thinking about it cancel each other out and the remaining will go on the neutral. 

I hope this helps you understand the different devices and how to be as safe as you can with your RV electrical on the AC side of it for you and your RV