[Timothy]

Originally Posted by TSoul

A house dryer is wired at 50 amps at 240 vac however nothing in a motorhome is 240vac and therefore it is wired differently. Each hot of the 50 amp service is on a seperate bar in the breaker box. It provides two lines of 50 amps at 120vac. So 50 amps on line 1 and 50 amps on line 2 equals 100 amps. At the sametime one must never plug into a house 240 line unless it is set up spacifically for an RV. If one would plug a 50amp motorhome in a 50amp dryer outlet one would effectively let all the smoke out of the electronics. And as we all should know the smoke must stay in the electronics in order for them to keep working.

Actually a house dryer is wired at 30 Amps 240 volts, and a house range would be wired at 50 amps 240 volts.
Provided the plug would fit, you could plug your 50 amp RV power cord into the range receptacle and it would work.

Just like your home panel the 50 amp panel in your RV has 2 busses, you would read 240 volts across those 2 busses, and while you may not need 240 volts for any one appliance in a motor home there is indeed 240 volts (limited to 50 amps) at your panel. I am assuming there is a 50 Amp 2 pole main breaker in your panel, if not then the breaker at the power box would be the 2 pole current limiting breaker.

To understand this you have to go back to the transformer that is providing power for the campground or your homes use, most transformers have a 7200 volt primary side with a 240 volt secondary. The secondary winding is center tapped and grounded, thus your would read 120 volts in either direction to ground from the secondary.
The two secondary lines are what provides the 240 volt (hot) power to the main buss or meter socket or whatever and the grounded center tap becomes the neutral.
Looking at your 50 amp rv plug you have 4 conductors, 2 are the hot conductors, one is the neutral conductor and one is equipment ground.
In most homes the equipment ground and the neutral are on the same buss in the electrical panel, however codes require them to be seperated in an RV or mobile home. If you look in your RV panel you will see all the white neutral wires going to one ground bar and all the bare wires going to another that comes from the green wire on your cord. If you have an genset, there will be a transfer switch somewhere too.

Whew, this is getting long winded!! OK now when you get to a park that has only 30 amp service, you plug your 30 amp adaptor into your 50 amp cord. The adaptor takes the 2 hot wires (that you normally would read 240 volts across) and ties them together, so now the 2 busses in your panel box are as one however the ampacity is restricted to 30 amps by the breaker at the feed box. Your cord is plenty big because it can carry 50 amps, so no worries there.

When one side of your panel (one hot wire) is conducting, the other side is not (in a sense) until current changes direction and both are limited to one cycle per second (60hz) so basicly your limited to 50 amps during that cycle. Keep in mind that current flow changes direction once a second and this should make more sense......I hope, I know I'm not very good at explaining things.
I do agree though that if you let the smoke out of your electronics they're toast!!!!