This is a diagram of a typical 50A male to 30A Female long DOGBONE ADAPTER.
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Please note that only one "HOT" leg of the 50A service is fed down to the 30A receptacle. This is still provided as a 50A leg from the source which is protected by a 50AMP Circuit breaker but is not of much concern as the trailer that is hooked up to it will have its 30A Main Circuit breaker to not allow anything over 30AMPS to be pulled by the trailer 30A Electrical System.
I carry one of these long DOGBONE adapters in my POPUP and have plugged into a 50A Service several time when camping. Sometimes you look at the 30A Service which is really used alot and the receptacle is really bad showing burned and arc marks whereas the 50A service receptacle is clean as a whistle. I just use the adapter and plug into the 50A Service then...
It has been safe for me to use...
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Google image
As always I like to use a multimeter to test any SHore Power Source to see if it is OK for me to use.
Here is two pictorials to use on what to measure and look for...
RV 50AMP SERVICE
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NO SHOCK ZONE Image
RV 30A/20A/15A SERVICE
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NO SHOCK ZONE Image
If I don't read the correct values as shown in the pictorials I will not hook up to the receptacle with my 30A Popup Trailer Shore Power Cable..
Roy Ken
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