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Oasisbob's avatar
Oasisbob
Explorer
Jul 25, 2019

15/30/50 SHORE POWER PLUG IN ?

My camper, listed below, uses what I believe is, a 30 amp shore power plug. I have a 15 amp adaptor. That is the standard looking plug in right? Am I correct in thinking a 50 amp connector is 220 volts? So is there an adaptor that allows me to plug into a 50 amp box using only one side? I ask as I am using a friends property and he has only 50 amp plug. It's kind of confusing atleast to me. Thanks
  • Dutchman is confused. If your friend has a 4 wire 220 plug that is exactly what you need. It is when people try plugging a 30 amp RV plug into a 220V 3 wire that gets them in trouble. Just remember that you are limited to the smaller of the 2 breakers as your friends plug could be anywhere from 30 to 60 amps.
  • Head on over to your local wallyworld, they have a variety of adapters to handle any scenario. No circuit breaker required on adapters as your RV has a main breaker that will instantly open upon reaching its rated value. We use our 50 amp adapter often for our 30 amp rig since many power pedestals at older parks have very worn 30 amp receptacles.
  • If your friend has a 50 amp 220 plug, don't use it. Chances are, the 50 to 30 amp RV adapter won't plug in anyway. More than likely, the 50 amp 220 plug was set up for a welder, at best a cloths dryer, or an electric oven .... all of which have different plugs form each other.

    You would be better off plugging your 30 amp camper into a 20 amp (110 volt) household plug with an RV step up adapter (20 to 30 amp). Your camper will still only have a max of 20 amps, but at least you won't blow up your wiring and electronics by plugging into a 220 volt power source.

    50 amp RVs use two legs of 110 volts, each rated at 50 amp. It is not 220. Your camper manages each leg so the overall usage in the entire camper never exceeds 50 amps. But it's still only 110 volts.

    My suggestion to be safe, plug into a 15-20 amp (110 volt) household plug with the RV adapter, either the "puck" or a "dogbone" adapter, and manage the power inside your camper so you won't pop the electric box breaker. Remember, if plugging into a 15 or 20 amp house hold electric socket, everything on the line uses part of that 15 or 20 amp; for example, lights inside the house, or appliances plugged into the same line. This reduces the available amp draw you can use inside your camper without popping a breaker switch.
  • stevenal wrote:
    These "adapters" don't seem to include circuit breakers. Your camper wiring and cord ahead of the camper's distribution panel is designed for use on a 30 A circuit protected with a 30 A breaker. The 50 A circuit will allow the wiring to overload and possibly catch fire. Are these things UL listed?

    Note that going the other way is not a problem, since 15 and 20 A breakers will protect the 30 A rated circuit. Doesn't your friend have a 15 A receptacle?


    Ah yes, the old "your 30 amp shore power cord could burn up if you use a 50 amp to 30 amp adapter". I did the calculations and a write up a while back on why the probability of that happening is non existent. I'm an electrical engineer. If you get a short circuit (most likely failure), then the 50 amp breaker will trip quickly. If you happen to get some fault that somehow takes in excess of 30 amps but less than 50 amps before your 30 amp breaker (extremely unlikely), then the cord will be dissipating about 100 watts. Not good, but won't necessarily burn up as much as getting warm. However, the other 5900 watts (at 50 amps) will definitely be making whatever is causing the fault to get very hot very quickly.

    An analogy: If you plug an appliance with an 18 AWG cord into a 20 amp outlet in your home, the cord is not rated for 20 amps, but the cord is not going to be the thing burning up if the appliance malfunctioned. Why? Because again, short circuits are far more likely and they will trip the breaker quickly. Even if it was an very unlikely partial failure that somehow took just under 20 amps, once again, the malfunctioning appliance would be catching on fire long before the cord.
  • These "adapters" don't seem to include circuit breakers. Your camper wiring and cord ahead of the camper's distribution panel is designed for use on a 30 A circuit protected with a 30 A breaker. The 50 A circuit will allow the wiring to overload and possibly catch fire. Are these things UL listed?

    Note that going the other way is not a problem, since 15 and 20 A breakers will protect the 30 A rated circuit. Doesn't your friend have a 15 A receptacle?
  • This is the answer I was hopeing for but was not sure. Thanks much
  • Just get a 50 amp to 30 amp adapter. You plug your 50 amp plug into it and then into the 30 amp pedestal. Easy peasy.

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