Surge is one of those words that has fallen into common usage when in fact; it's not very descriptive of the situation. Electrical voltage (pressure) needs to be near a certain amount for electrical gear (like your computer) to be happy. And the voltage (pressure) we use in the USA is rated at 120 volts, give or take 5% according to the National Electrical Code. That means it could vary from a low of 114 volts to a high of 126 volts, and still be strictly within code. From a realistic standpoint though, it's more likely to be as much as 8% low, so a 110 volt measurement is pretty common. Common cause of voltage spikes are big motors being turned off, which then induces a reverse voltage spike of 10 to 100 times the nominal voltage. Again, these are short duration spikes of only a few milliseconds (1/1000 of a second) so a MOV protected "surge strip" will do a good job of shunting this voltage to ground without harm. I think the most common cause of this type of spike would be a big water pump at a campground when it switches off. However, there are voltage "spikes" that can be induced on a power line from a variety of causes, the most dramatic one being a lighting strike near your area. That can cause a voltage "spike" of many hundreds or even thousands of volts to appear on your 120-volt wiring. Fortunately, that "spike" only lasts for a tiny fraction of a second (milliseconds) so it's pretty easy to get rid of with a simple MOV device (Metal Oxide Varistor) built into a common "surge" strip which shorts these high-voltage spikes harmlessly to ground. There's an even bigger electrical boogie man at campgrounds that many RV’ers are unaware of. And that's sustained over and under voltage conditions. This is where the voltage going into your coach from the power pedestal can dip very low (say, below 90 volts) or swing very high (180 volts or more) depending on the condition. And there have been instances where entire campground areas have been miswired with 208 volts instead of 120 volts. And certainly, a broken neutral connection in your 120/240 volt shore power plug can let the one side of your power dip to 60 volts while the other side rises to 180 volts with predictable disaster. In that case, the MOV in your surge strip will think that nothing is wrong and happily pass 180 volts right into your computer and microwave. Then it's new appliance time. I would get some sort of overall protector on the shore power connector. So do you spend $99 on an RV "surge protector" or $300 to $500 on a "voltage protector"? Well, that's up to you. But considering that the cost of an RV refrigerator or microwave can be $1,000 and up, plus the cost of all the electrical things you plug in like computers, iPods, phone chargers, etc., I think the $300 to $500 of a voltage protector to be well worth the investment, and probably costs less than the deductible on your RV insurance policy.
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Posted on 10/27/2014 at 1:58:00 AM