Shore Power Question -- (15A+30A=45A)

jdc1 wrote:
One question, three different answers. That's why this forum is so popular. Everyone gets their say, and they don't get ridiculed for it.

Only if something else is wired improperly. This highlights a common misconception. A lot of people think the difference between 30A and 50A service is 20A. But that's not really accurate. Really the difference is 70A. 30A service is 30A at 110V where 50A service is 2 50A 110V circuits. This is almost always implemented as a 50A 220V circuit on the power pedestal. Any time you use a 50A to 30A dog-bone though, it connects both legs together supplying the single 30A 110V circuit to both of the 50A circuits in the RV. This dual circuit adapter does not connect the 15A circuit and the 30A circuit together internally, so unless something within the RV connects them, connecting one but not the other should not result in voltage to the disconnected plug. However, as DrewE suggested, if there is a fault in the RV wiring or "true" 220V appliance in the RV, it could result in voltage on the unattached plug.

However, the biggest reason not to use one of these is that unless you have special circumstances, they almost always gain you no additional capacity. Most power pedestals that offer a 30A circuit and a 15/20A outlet aren't powered by separate circuits and the pedestal is limited to 30A not 50A. So in this case, using a standard 50A to 30A dog-bone gets you the same amount of power. Now you could, in theory, use this adapter to get power from two different pedestals, but even if campgrounds would allow this, as already suggested the required GFCI on the 15/20A receptacle would likely immediately trip.