I’ve written a number of articles here about surge protectors and the difference between intelligent and basic models. The overview is that basic surge protectors usually cost less than $100 and offer protection from nearby lightning strikes and voltage spikes on the incoming power line. However, they can’t protect your RV from an over-voltage condition that occurs if you happen to connect your 30-amp shore power plug into a pedestal outlet that’s miswired with 240 volts instead of 120 volts, as is clearly labeled on the front of the outlet. When that happens it can destroy much of your RV’s expensive electrical system in seconds.
On the other hand, an “intelligent” surge protector from Progressive Industries or Surge Guard will indeed disconnect your RV from an over-voltage pedestal before damage occurs. But brains don’t come cheap, with the price of a 30-amp intelligent surge protector costing around $300, and a 50-amp version costing as much as $500. So is that much of an investment really worth it? Does this kind of miswiring condition happen routinely or just once in a blue moon?
With that question in mind I ran a survey last week in my RV Electricity Newsletter asking how many of you had encountered a 30-amp/120-volt pedestal outlet miswired with 240 volts. Both editor Chuck Woodbury and I were astounded to discover that 10% of you had indeed found one in the wild. See the survey below, which is still active and will accept your vote.
What does this all mean? Well, I would have guessed maybe 1% of our readers would have encountered a miswired 30-amp pedestal, but it appears to be pretty common. And you know from reading my articles about voltage that many of the electrical systems in your RV will be destroyed in seconds from this kind of abuse.
So what can you do to protect your investment? Well, I know you don’t like to spend money, but in this case I think it’s the wisest thing you can do. Here are two examples of 30-amp intelligent surge protectors on Amazon that I’ve personally tested, and either should do a great job of protecting your RV from static over-voltage conditions as well as any voltage spikes. Progressive / Surge Guard and here’s the latest Surge Guard model which isn’t available on Amazon just yet.
Who’s to blame for this miswiring epidemic? Well, I don’t think it’s any single party. Certainly the NEMA TT-30 outlet form factor has to take some of the blame since it so closely resembles an old 30-amp/240-volt dryer outlet. (Click the picture on the right for a full-size image.) And the electricians or technicians who install them incorrectly should take some of the blame since the outlets are marked quite plainly for 125 volts. But in the final analysis, you the RV owner must take at least some responsibility for making sure whatever you plug into is within electrical specs. Until there’s some nationwide test-and-tag program for all campground and home pedestals with a bonded/insurance rider that will pay for any RV damage from over-voltage, it’s still up to you to be the final authority on verifying voltage before plugging in.
So until you get your own smart surge protector, it’s good to brush up on testing your pedestal with a digital meter before plugging in. I’m getting ready to produce a bunch of new Electric Videos on this and other electrical topics in a few weeks, but for now here’s a video on pedestal testing I published a few years ago.
Let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 40 years in the industry. Visit NoShockZone.org for more electrical safety tips. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.