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Comments for Surge protector for 30- or 50-amp outlets

  • Something else to think about the 50 to 30 (and reverse) is the 30 amp connection in parks are used more and a lot of time by renters and newbys who have not learned what they are doing. That means the 30 amp receptacle may really be beat up or even broken or chipped. With the dogbone you can use the 50 amp side which will most of the time be in a lot better shape. Have phun.

  • I’m proposing a yearly inspection of all campground pedestals for exactly that reason. Pedestal power outlets take a real beating, which can cause lost grounds and neutrals as well as overheated connections that can melt and catch fire. Proper maintenance is the only way to guarantee everyone’s safety.

  • Not so much a comment as a question (I don’t know how else to contact you). I have a 30-amp TRC surge protector that analyzes the pedestal before passing on current. Recently, I plugged in and the unit reported a Reverse Polarity condition, but it passed the current through anyway. Since I didn’t have many other options (this was not in a campground) I plugged into the motorhome and continued as usual. As it happened, I didn’t need to use any 110V appliances other than a CPAP. Everything seemed normal.

    What is the danger, if any, to using a power pedestal that has reverse polarity?

    • By itself, a reversed polarity outlet is not dangerous. It won’t cause a hot-skin condition by itself, and all appliances should operate normally. However, if there was a secondary Ground-Neutral bond in your RV (definitely a code violation itself), then you would either trip the main circuit breaker, or create a hot-skin voltage on your RV. Plus, if anyone was working on an electrical appliance inside of your RV while plugged in, and they assume that the white/neutral wiring isn’t energized, then they could be at risk of shock or electrocution. Plus, it’s the basic details that hint at the overall condition of the wiring in a facility. If they can’t even get something simple like the hot-neutral polarity wired correctly, what even more important details have they missed?

  • Am I understanding that you could take a 50 amp surge protector and plug a 30 amp RV into the 50 amp receptacle with the dogbones and be safe?

  • Not really, according to code. While it certainly would work, that situation would make it possible to draw more current through your 30 amp wiring than it’s rated for, and thus the possibility of a fire. Going the other way is fine since a 30-amp outlet can only supply 30 amperes of current into wiring that’s rated for 50 amps. So overheating of the conductors isn’t possible that way.
    I know there are all sorts of dogbone adapters that allow you to plug your 30-amp shore power cable into a 50 amp pedestal outlet, but that’s also a code violation and could cause a fire if you overload your 30-amp cable with 50-amps of current. So I can’t recommend that sort of hookup.

  • Reverse polarity may not hurt normal electrical appliances but it can fry electronics. Some inverter converters have sacrificial diodes which fry the charging circuits if reverse polarity. I have a 1000 dollar repair bill to prove it. Contact Tripp lite for more info. My new progressive surge protector does pick up reverse polarity but if it does not shut down for that error I still have exposure if current passes. I check before hook up but in unlikely situation it occurred later it’s a problem. Comments?

    • I’m not sure you’re correct about reversed polarity destroying your Tripp Lite unit. What model number do you have? I’m going to contact Tripp Lite tech support and get a schematic of its circuitry. In a previous life I was a pretty good circuit designer, so it will be interesting to learn exactly what they’re doing inside the box and if reversed polarity can indeed damage it. And if they’ll send me a unit to test, I’ll set it up with reversed polarity and see how it responds. No modern electronics should be damaged by a simple neutral-hot swap.

      • Getting ready to travel so will respond with specifics when i get on road but it definitely ruined the charging circuitry. The inverter part was working fine but I could not charge the batteries thru the generator or plugged in. I found several articles discussing the impact on sensitive electronic with reversed polarity.issues. I had to prove my case to the state park that had the issue. The inverter/converter was 9 years old . It was hard wired and I think 600watts. I don’t remember exactly what wires were wrong but the 20amp plug was fine so not voltage issue.be interested in what you find out. Thanks for the response.

        • If you’re referring to a reversed polarity on the DC side of the inverter, then yes that will destroy electronics in seconds. But a pedestal can only reverse the 120-volt AC polarity. Again, I’m not sure that any modern electronics can be harmed by a swapped hot-neutral. But I can see if there was some aftermarket diode clamping circuitry added (by the dealer or RV builder?) that strange things could happen on the AC side. I’ll need the exact model number of the inverter and maybe a photo of how it was hooked up. Email anything to mike@noshockzone.org.

  • Always remember that a surge protector is not a circuit breaker. It can’t limit the amount of current that passes through it. A surge protector can only clamp voltage spikes from things like nearby lightning strikes and water pump motor generated back EMF. It is the job of the circuit breakers in the Pedestal to limit the amount of current draw by your RV to 50, 30 or 20 amperes, depending on which outlet you’re plugged into and how heavy your shore power wiring is.

  • Something else to think about with the type of surge protector shown is the “STEALability of the Protector. Lets face it, not everyone in an RV is honest and laying they’re hands on a costly RV surge protector is a prize! Be sure your surge protector cannot be just un plugged and taken. I opted for the permanently installed kind and not the plugin type.

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