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30 amp & 20 amp to make 50 amp

honda1
Explorer
Explorer
does this work or is the 30 & 20 side feed each other , just going to make 20 or 30 side pop c.b. or worth making one to have just in case ?.
32 REPLIES 32

SDcampowneroper
Explorer
Explorer
Many older camps, including a small original section of ours has 30 /20 A peds. They are 'spider ' wired back to a primary breaker at the main panel. They are on one 'leg', and neutral so no cheater will give more than the nominal 120v 30 A the main breaker at the remote panel allows. It was legal then, is still grandfathered, no issues.
Balanced 'loop' wiring provides all 240v up to 600 A in every pedestal depending on cable size so they can support cheater 30-20 plugs only if the 20 is not a gfci.
The only true way you can get more out of a 30/20 ped. is if you know its loop wired,with # 6 or larger to each breaker, so you can you plug in separate cords to each outlet to supply separate loads.
Ask the camp about it.

Dutch_12078
Explorer II
Explorer II
Lantley wrote:
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.


On our current 50 amp coach, since our second A/C is on it's own breaker, doing a similar separate cord setup is even easier than the old 30 amp setup. All I need to do is loop the line from the breaker to the A/C out from the breaker panel to a convenient external location and insert the plug set with the male on the A/C side. On 30 amp park power, I would then just need to unplug the A/C connection and plug it into a 12ga extension cord connected to the park panel's 20 amp utility outlet so both A/C's could be used at the same time just as they were on the 30 amp coach.
Dutch
2001 GBM Landau 34' Class A
F53 chassis, Triton V10, TST TPMS
Bigfoot Automatic Leveling System
2011 Toyota RAV4 4WD/Remco pump
ReadyBrute Elite tow bar/Blue Ox baseplate

Lantley
Nomad
Nomad
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.
19'Duramax w/hips, 2022 Alliance Paradigm 390MP >BD3,r,22" Blackstone
r,RV760 w/BC20,Glow Steps, Enduraplas25,Pedego
BakFlip,RVLock,Prog.50A surge ,Hughes autoformer
Porta Bote 8.0 Nissan, Sailun S637

Dutch_12078
Explorer II
Explorer II
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
2001 GBM Landau 34' Class A
F53 chassis, Triton V10, TST TPMS
Bigfoot Automatic Leveling System
2011 Toyota RAV4 4WD/Remco pump
ReadyBrute Elite tow bar/Blue Ox baseplate

honda1
Explorer
Explorer
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. ..

DrewE
Explorer II
Explorer II
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).

BB_TX
Nomad
Nomad
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.

enblethen
Nomad
Nomad
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.

Bud
USAF Retired
Pace Arrow


2003 Chev Ice Road Tracker

CA_Traveler
Explorer III
Explorer III
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
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob

ScottG
Nomad
Nomad
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

DrewE
Explorer II
Explorer II
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.

Bobbo
Explorer II
Explorer II
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.
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB

BB_TX
Nomad
Nomad
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.

Bobbo
Explorer II
Explorer II
CA Traveler wrote:
enblethen wrote:
The two circuits must be on different phases of the electrical source.
Split phase is not needed for the 30+20 amp cheater cord connection as the 50A RV neutral cannot be overloaded.

You could argue that the cheater cord connected to 30+30 amp (which I've done) could overload the 50A rated neutral if the connection is not split phase.

I have a different understanding of the question than you do. I understand that he has a 50 amp RV and wants to use this on a pedestal without a 50 amp outlet, but use the cheater to at least get 6000 watts. 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.

As far as 50/30/20 amp boxes, I bet if you check 100 of them, you will find some that have the 30 and 20 outlets on the same leg, and some that they are on different legs. There will be no uniformity.
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab w/Max Tow Package 3.5l EcoBoost V6
2017 Airstream Flying Cloud 23FB