30 amp & 20 amp to make 50 amp

BB_TX wrote:

Bobbo wrote:
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In this case, there is no 50 amp neutral. The 30 amp neutral definitely can be overloaded, if the 30 amp and 20 amp outlets are not fed from the same main breaker, but are still on the same leg.
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Actually there is a 50 amp neutral all the way from the RV load center to the end of the 50 amp cord where it would plug into the adapter. Then the neutral splits into a 30 amp neutral to the 30 amp plug and a 20 amp neutral to the 20 amp plug. And those two neutrals would connect inside the pedestal.

There is no 50 amp neutral from the pedestal to the main box feeding it. That 30 amp neutral can be overloaded too.

Bobbo wrote:

BB_TX wrote:

Bobbo wrote:
...........
In this case, there is no 50 amp neutral. The 30 amp neutral definitely can be overloaded, if the 30 amp and 20 amp outlets are not fed from the same main breaker, but are still on the same leg.
.............

Actually there is a 50 amp neutral all the way from the RV load center to the end of the 50 amp cord where it would plug into the adapter. Then the neutral splits into a 30 amp neutral to the 30 amp plug and a 20 amp neutral to the 20 amp plug. And those two neutrals would connect inside the pedestal.

There is no 50 amp neutral from the pedestal to the main box feeding it. That 30 amp neutral can be overloaded too.

There are a number of more or less valid concerns with these "cheater" cords, and overloading the neutrals at the campground is one that is valid. In particular, if the 30A or the 20A neutral were poor or open, it's entirely possible that 50A could all flow through one of them, and 50A on a 12 gauge wire is a quite significant overload.

Also, if either the 30A or the 20A outlet has hot and neutral reversed (which often can go unnoticed and causes no immediate problems), plugging the adapter in causes a hard short between hot and neutral. One hopes the breakers are reliable in that case and trip properly...and the vast majority of time that's what happens, fortunately.

If there's a GFCI involved, it will of course quite properly trip.

j-d wrote:
I've worked on 50A campground pedestals, but I didn't notice if the 30A and 20A receptacles were on opposite legs of the 50.

They are are indeed on separate legs if using the standard 100 amp panel with 50. 30, 20 recepts.

Cheers,
Scott

Thanks for the reminder. Yes the 20A or the 30A neutral can be overloaded in the adapter but not the RV wiring.

And adapters with 2 30A male plugs there are an additional 10A.

The adapters short (connect if you like) the two neutrals in the adapter and that opens the door for either to carry more amps than it's corresponding hot. This is definitely not done in normal wiring

Many older parks that do not have 50 amp 120/240 receptacles have a single 120 volt circuit. Why? To save money! There were not that many 50 amp 120/240 rigs around so why spend the dollars.

Bobbo wrote:

BB_TX wrote:

Bobbo wrote:
...........
In this case, there is no 50 amp neutral. The 30 amp neutral definitely can be overloaded, if the 30 amp and 20 amp outlets are not fed from the same main breaker, but are still on the same leg.
.............

Actually there is a 50 amp neutral all the way from the RV load center to the end of the 50 amp cord where it would plug into the adapter. Then the neutral splits into a 30 amp neutral to the 30 amp plug and a 20 amp neutral to the 20 amp plug. And those two neutrals would connect inside the pedestal.

There is no 50 amp neutral from the pedestal to the main box feeding it. That 30 amp neutral can be overloaded too.

If the pedastal has both a 30 amp and a 20 amp outlet then the neutral from the pedastal to the primary source should be capable of carrying the current for both outlets, or the contractor should have his license revoked.

BB_TX wrote:

Bobbo wrote:

BB_TX wrote:

Bobbo wrote:
...........
In this case, there is no 50 amp neutral. The 30 amp neutral definitely can be overloaded, if the 30 amp and 20 amp outlets are not fed from the same main breaker, but are still on the same leg.
.............

Actually there is a 50 amp neutral all the way from the RV load center to the end of the 50 amp cord where it would plug into the adapter. Then the neutral splits into a 30 amp neutral to the 30 amp plug and a 20 amp neutral to the 20 amp plug. And those two neutrals would connect inside the pedestal.

There is no 50 amp neutral from the pedestal to the main box feeding it. That 30 amp neutral can be overloaded too.

If the pedastal has both a 30 amp and a 20 amp outlet then the neutral from the pedastal to the primary source should be capable of carrying the current for both outlets, or the contractor should have his license revoked.

Assuming the 20A isn't slaved off the 30A breaker, that's true--and if they are slaved, and so the whole pedestal is limited to 30A, it's a moot point anyhow. However, the connection from the 20A or 30A socket to the neutral bus in the pedestal would not be oversized (generally speaking).

i have 50 amp plug on r v , only 1 ac , but if i go to state parks most only have 30 amp , thats why i asked , but has been stated if have 20 amp gfi game off & or wasnt wired right pops c.b. , better off 30 amp plug adapter to 50 & frig & w.h. on l.p. ..

Running the second A/C in our previous 30 amp coach on a separate 20 amp cord to the park utility outlet when needed was a simple low cost conversion process. We haven't needed it yet in our current 50 amp coach, but I could easily do a similar conversion if that changes. The only parts involved were a 4x4" junction box extender, a 20 amp male/female plug pair, and some short lengths of wire. A 12ga extension cord connects the setup to the park box. Total cost about $20. Of course if the 20 amp breaker was slaved off the 30 amp breaker, then that was an issue...

Dutch_12078 wrote:
Running the second A/C in our previous 30 amp coach on a separate 20 amp cord to the park utility outlet when needed was a simple low cost conversion process. We haven't needed it yet in our current 50 amp coach, but I could easily do a similar conversion if that changes. The only parts involved were a 4x4" junction box extender, a 20 amp male/female plug pair, and some short lengths of wire. A 12ga extension cord connects the setup to the park box. Total cost about $20. Of course if the 20 amp breaker was slaved off the 30 amp breaker, then that was an issue...

Connecting it to a 50 amp circuit is not quite as simple as using a 30 amp circuit.
Were you able to run both A/C's on a single 30 amp circuit. Most people can't or it is hit or miss.