30/ 50 amp pedestals

[bwanna2016]

not sure if this is the category to ask this but here goes. we are at a city park that provides the standard 30/50 amp outlets at the pedestal. the one next to us has a class c running to the 30 amp outlet. another unit pulled in and plugged into their 50 amp outlet. same panel. does this affect the amperage/ voltage to either unit?

[wolfe10]

If (read that big IF) the park wiring is of proper gauge, all is fine.


But, when starting high-amp loads like roof A/C, verify that voltage does not drop below 108 VDC. THAT is the thing to watch.



Don't worry about amps, the breakers will not limit draw.

[dizcom]

It might. There are pedestals that are 50 amp and that's all you get. There are plugs for 30 amp and 20 amp, but it's not 100 amps, it's only 50. Idea is that only one gets used at a time. I suppose you could run 50 and 30 and 20 to each pedestal in your campground, but why would you? On the other hand, it's unlikely that the unit using the 50 amp is using the whole 50 amps, but I wouldn't want to play with that if I didn't have to.

[bwanna2016]

it is not my intention to run more than 50 amps. i'm just wondering if the 2 rv's were now sharing the amps. i'm not an electrician, but i'd like some info in case this situation would happen to me.

[rarebear.nm]

RV power pedestals do not have any kind of amperage limit provided to it other than the buried feeder wire and the breaker at some up line panel. Frequently they use 4 or 6 gauge wire for the buried feeder lines. How much amperage is partially depended on the distance from the brach circuit's feeder panel.

So to answer your question about sharing amperage, I guess you could say yes in a limited sense. The limit on the branch circuit is a function of the distance, wire size and feeder breaker.

[Talloaks]

Originally Posted by rarebear.nm

RV power pedestals do not have any kind of amperage limit provided to it other than the buried feeder wire and the breaker at some up line panel.

I have provided the links below to three different sources for RV power pedestals, along with their specs and ratings. Pedestals with 50, 30, and 20 amp receptacles are rated at 100 to 125 amps, so they should be wired with conductors of sufficient capacity, and protected with a feeder breaker of the same rating. At the pedestal, each receptacle has its own supply breaker.


Pedestals with only a 30 and a 20 amp receptacle may be rated at only 70 amps or less.




IF... the installation has been done in this manner, then your park neighbors would be sharing the 100 or 125 amp feed to the pedestal, so there would be plenty of margin. However, there is no question that there are parks out there that are not wired to this standard.



https://www.homedepot.com/p/GE-RV-Pa...2PSL/300325159


https://bbelec.com/rv-park-pedestals-surface-boxes/


http://www.rvparksupplies.com/p/503020AMPPEDPOWER/

[Persistent]

All good advice above!
The answer is of course, it could be many different conditions you usually can not know about.

The advice to monitor line voltage while motors are running is the best. Many RV "surge protectors" will monitor the line voltage and some will automatically disconnect if voltage drops.

If you are running a 50 amp 240 volt system you should be using a "surge protector" for many reasons including low voltage.

Some places have codes in force. Some do not. Some codes are different.

Main service panels in homes do not have enough input capacity to cover maximum draw by all breakers. Main breaker will limit. We all get along just fine in our homes. We never use maximum output through all outlets.

A pedestal is a sub-panel. It also does not necessarily have enough input supply to provide for maximum draw from all output circuits.

Knowledgeable people can share outlets as long as they cooperate and limit use. I have seen multiple small units plugged into a common 20 amp outlet. They got along successfully. The key is "cooperation" and "limited use".

I wish you good luck and happy trails ahead!

[DutchmenSpor]

I had installed a 20/30/50 amp receptacle at my home. It feeds to a 80 amp breaker at the main box coming into our electrical system. I could run the full 50 and the full 20 or 30 at the same time. But add the third, and the main 80 amp breaker at the main junction will pop.

[amosnandy]

Originally Posted by bwanna2016

not sure if this is the category to ask this but here goes. we are at a city park that provides the standard 30/50 amp outlets at the pedestal. the one next to us has a class c running to the 30 amp outlet. another unit pulled in and plugged into their 50 amp outlet. same panel. does this affect the amperage/ voltage to either unit?

Pretty well covered here but to simplify, there are really 2 ways to wire a 50/30/20 amp pedestal.

The first is to run the feeder wire, usually 6/6/6/8 (if copper) to the 50 amp breaker. 6/6/6/8 is what most 50 amp rv power cords are. In a long run a CG may run 4/4/4/6 due to voltage loss on the long run. Then the 50 amp breaker feeds the 30 amp and 20 amp. So the maximum any combination that could be drawn is 50 amps.

The other way, and this is the way most codes require, is they run aluminum to the busbar at the pedestal. 100 amp aluminum requires 2#/2#/2#/4# and it is connected directly to the busbar. Then you can snap in a 50 and a 30 and a 20 amp breaker and outlet.

Running a 50 amp and a 30 amp on the first setup could be a problem if the combination of the 2 units exceeds 50 amps. What would probably happen is the 50 amp on the pedestal would trip.

On the second setup, since each breaker is independent of each other then yes, one could pull 50 and the other 30 without a problem.

In a city park, most likely the pedestals are wire up to code so no problem.

[KanzKran]

Many park pedestals are rated for 250 to 300A feeders and 350 MCM cable, like the third link in Talloaks' post above. You could put up to 12 of those with 50A receptacles on a single feeder, with the 0.50 demand factor the NEC allows for 10-12 sites on a feeder.

So it would be impossible to say what another coach would do to the voltage when plugged into the same pedestal without knowing something about how they're wired.

[PandS]

We recently spent a week in a Minnesota campground hooked up that way. We experienced no problems, but we run a Hughes Autoformer. So there's that grain of salt to consider. -Paul

[Gary RVRoamer]

The other way, and this is the way most codes require, is they run aluminum to the busbar at the pedestal. 100 amp aluminum requires 2#/2#/2#/4# and it is connected directly to the busbar. Then you can snap in a 50 and a 30 and a 20 amp breaker and outlet.

I've worked and done electrical maintenance in several parks and never saw one with a 100A feed to a 50/30/20 pedestal. The most common was a basic 50A/240v feed using 6/6/6/8 wire. The 50/240v + 30A/120v + 15A/120v outlets does not over-commit that beyond code requirements in most states. Electrically that is no different than daisy chaining 4 or so 15A outlets on a single 15A circuit & breaker, as is common in homes & offices across the nation. As long as the feeder breaker is sized for the wire, there is no overload danger.


In any case, yes, everything plugged into that pedestal is "sharing the amps". Whether that sharing can drag down voltage or unexpectedly trip breakers depends on the power draw in each RV and the exact method of wiring the pedestal. There is no way for you to tell from the outside - you would need to measure voltage under various conditions. In my opinion, typically there would NOT be a noticeable voltage drop, but a "worst case" scenario is possible where that would happen.

[twinboat]

Originally Posted by DutchmenSpor

I had installed a 20/30/50 amp receptacle at my home. It feeds to a 80 amp breaker at the main box coming into our electrical system. I could run the full 50 and the full 20 or 30 at the same time. But add the third, and the main 80 amp breaker at the main junction will pop.

If you wired it properly, one leg would handle 80 amps, L1 of the 50 amp outlet and L of the 30 amp outlet.

The other leg would handle 70 amps, L2 of the 50 amp outlet and L of the 20 amp outlet.

50 amp outlets are 120/250 2 leg power.
20 and 30 amp outlets are 120 volt only.

The 80 amp breaker will hold fine.

[twinboat]

In case anyone is confused, here is how RV power works.

https://www.rvtechmag.com/electrical/chapter3.php