How to protect your RV Electric System
Your RV, being your home away from home, contains many electric items that bring comfort and convenience while traveling. Refrigerator, microwave, television and computers require electricity to operate and as such are subject to electric damage from voltage spikes and low voltage operation. Below we outline what makes up your RV electric system along with inexpensive ways to provide protection

Before we get into details about protecting your RV electrical system there is one product that  is a must have for all RV owners.
"KILL A WATT"  is a small handheld device that gives you tons of information about your RV electric and can be purchased for about $20. Here are just some of the information the device provides:

1. Plug it into any electrical outlet and it will first tell you if the outlet is getting electricity and also will provide you will the amount of voltage the outlet is getting. This will provide you with the information of the amount of voltage the RV Park is providing.  Note, voltage that is to low or high can damage electrical items in your RV.
2. Plug any electrical item in the outlet on the front and you will get a read-out of the amount of amps the item is using along will the wattage being produced.  You will be able to  calculate the total amperage your RV is using while electrical items are in use.
3. You can also us it to check if electrical items are working correctly. If you have a electric space heater and you feel that it is not putting out the amount of heat you believe it should. Plug the heater into the Kill-A-Watt and you will be able to see what the heater is producing. Lets say the heaters manual states that on low setting it will produce 1000 watts. If the reading you get is 700 watts you will know that it is time to replace the heater.
4. Kill-A-Watt can be used either at home or in your RV.

The electrical system in almost all modern RV units are very similar. The main difference is the amount of amps that the unit is designed to operate with. Smaller RV are equipped with a 30 amp system while larger ones have a 50 amp system.
You do not need a degree in electrical engineering to understand your RV electrical system. All you need is a basic understanding of these three terms: (Voltage, Amps and Watts).
Voltage is the strength of the current through your RV electrical system and should have a reading around 115 volts.
Ampere or Amps is the amount of current in the electrical line.
Watts is the total electrical power released through the circuit in a second.
For a simple understanding think of it in the way your car operates. Your car has an engine and a tank filled with gasoline. When the car is not running it still has the gasoline in the tank and fuel line. Think of the gasoline as voltage.
When you start the car the gasoline goes into the engine at a rate determined on how far you push down the accelerator pedal. Think of the engine as resistance and the faster it is running the more gas is required per second of running time. Think of this measurement as Ampere or Amps
Now when you put the car in gear the engine is providing the power to turn your wheels. The more gas you give the engine the faster the wheels will turn. Think of this measurement as Watts.

You might wonder why your RV needs additional electrical protection when it has circuit breakers. The answer to that is how circuit breakers work.
Circuit breakers work by passing the electrical current through either a electromagnet or bimetallic strip.
If the breaker is using a electromagnet strip as the flow of electric increases the electromagnet becomes stronger until it reaches a unsafe point strong enough to pull down a metal strip and thus closes the circuit.

If the breaker is using a bimetallic strip as the flow of electric increases the strip bends until the bend is strong enough to close the circuit. Because both work mechanically a short period of time elapse before the breaker closes. This time lapse can cause damage. Surge protectors work in milliseconds. 

Now that you are an expert in how electricity works lets get on to protecting your RV electrical system in an inexpensive way.  Your RV has two different electrical systems, one using AC electricity and the other using DC electricity. The DC system is pretty much self protected by the DC fuses in your RV and something you don't have to worry about.  The AC system is what we need to protect.
Below are 3 images showing the RV Electrical Layout.
The first image is your electrical items needing electricity.
The second image is how electricity passes through your RV.
The third image is your RV DC system. Clicking on the image will expand in a separate window.
Protecting Your RV from Electrical Spikes and Surges.
Below we outline protection techniques and products from the electricity point of entry up to each electrical product in your RV.
Protecting the 30 or 50 amp connection to the RV Park shore power.
Their are many 30 and 50 amp RV surge protectors on the market with many costing hundreds of dollars.
The more the readings on the surge protector the more the cost. You don't need fancy digital readings at this point. All you need is to know the outlets polarity and voltage is correct. Your can use your "KILL-A-WATT" to check readings on the inside circuits.

Protecting the electrical items inside your RV

You might ask "If I am using a 30 or 50 amp surge protector where I plug the RV into the Parks power, why do I need protection inside?" Click here for the answer.

For items that are not hard wired to the circuit breaker use an inexpensive surge protector.
For the refrigeration use a single outlet surge protector.
For the TV, Computer and Stereo System use a multiple outlet surge protector.
Your microwave will present a problem. Most RV microwaves require a 20 amp circuit because of the wattage produced. Your standard surge protector can only handle up to 15 amps and will shut the microwave off during a cooking time over 8 minutes. Surge protectors not only protect against electrical spikes but also contain a 15 amp circuit breaker. Going to a 20 amp surge protector becomes expensive and thus may not be worth the cost.
Your AC and Converter box are hard wired directly to the circuit breaker and thus no place to put a surge protector.


Why are internal surge protectors needed when you are using a 30 or 50 amp external RV surge protector?
The picture below is of a 50 amp outlet, damaged by spider cobwebs while, plugged into a RV Park outlet.
There was just enough space for a very tiny spider to spin a web around the poles of the RV plug.
Cobwebs will not conduct electricity but water will.
In the early morning hours dew was able to form on the web and thus completing a electrical connection between the hot wire on the right and the neutral wire on the bottom.
A quick surge of electricity was able to completely go thru the RV's neutral wire system and destroy everything that was on and not connected to a surge protector.
Items that were on meaning power was being used by the item. Luckily The refrigerator and AC were not calling for power at the time of the surge. The microwave is always calling for power due to its built in clock.

Total damage in this accident.
AC/DC Converter box $150,
RV Microwave $150,
50 amp RV cord plug and 50 amp outlet $50,
surge protectors $50. Of course the 5 inexpensive surge protectors were destroyed but they protected the items connected.
This accident would have still occurred even if the RV cord was plugged into a surge protector. Rule of thumb. Always check your connected RV cord that a space between the plug and outlet did not develop and thus providing room for small spiders to string their webs.