Use both 50amp and 30amp at same time?

[drizzamed]

Can you physically plug both a 50amp cord (for RV) and also a 30amp (for other electrical device that needs 20amps) in at the same time at the site box (shore)? Like is there physically enough room for both plugs?

 

[Viajeros]

Sort of and depends.

We plug our 50 amp coach and 30’amp electric car charger in at the same time. The receptacles are on their own breakers. But on our lot there is a main breaker (not on the site) that is still only 60 amps. So yes, but you need to monitor loads...and to some degree balance the loads as the 30 amp loads down only one side of the 50 amp 240 feed. Our electric vehicle charger draws 24 amps at 120 volts when on a TT30 receptacle.

Does that make sense? I’m not good at these explanations.

 

[SeilerBird]

It is possible. The limiting factor is if the pedestal can handle it. If it can't handle it then it will trip a breaker.

 

[DonTom]

Can you physically plug both a 50amp cord (for RV) and also a 30amp (for other electrical device that needs 20amps) in at the same time at the site box (shore)? Like is there physically enough room for both plugs?

The wires to the site box would have 80 amps on them if both are used to to max. So the question is if the wiring can handle 80 amps.

It's more of a question for an electrician, but I will assume they have to be wired for that 80 amps by local codes. I say this because when I had my 60 amp circuits added to my houses (not on wheels) the electrician was required to make sure every item could be on at the same time without going over the capacity of the box, with a 20% safety factor added in.

So I would assume just because there are two outlets, one rated for 50 and the other for 30, that the wiring would be good for 96 amps min (included that 20% for safety).

But I am not an electrician, so I am only making assumptions and the electrical codes can be different in different areas. But my guess is it will be wired for 100 amps. 2 gauge wires?

-Don- Cold Springs Station RV Park, NV

 

[Kirk]

Like is there physically enough room for both plugs?

In most cases the answer is yes, but it will depend on the configuration of the power pedestal used.

 

[drizzamed]

Sort of and depends.

We plug our 50 amp coach and 30’amp electric car charger in at the same time. The receptacles are on their own breakers. But on our lot there is a main breaker (not on the site) that is still only 60 amps. So yes, but you need to monitor loads...and to some degree balance the loads as the 30 amp loads down only one side of the 50 amp 240 feed. Our electric vehicle charger draws 24 amps at 120 volts when on a TT30 receptacle.

Does that make sense? I’m not good at these explanations.

Yea I think so. Basically I need to ask what the amperage is coming in at my pedestal? So I can determine if both the RV and electrical device has plenty of load so one doesn't fall out?

 

[mnmnutswer]

Can you physically plug both a 50amp cord (for RV) and also a 30amp (for other electrical device that needs 20amps) in at the same time at the site box (shore)? Like is there physically enough room for both plugs?

My motor home is 30 amp. I adapt to 50 then use 30 for other electric items.

 

[drizzamed]

My motor home is 30 amp. I adapt to 50 then use 30 for other electric items.

I can't do that because I'd over draw on the 50 alone.

 

[Kirk]

So I can determine if both the RV and electrical device has plenty of load so one doesn't fall out?

If the pedestal is one that has a circuit breaker for each outlet in that box, you just look at the breakers as they will have the trip point on them. Using both at the same time could run into a limit of the circuit that is supplying the pedestal, but that isn't likely in a park with many pedestals as there would usually be one set of breakers for both legs of power to a larger group of RVs. Circuit breakers in these situations are sized based upon the wire size used to connect things and the breakers on the pedestal are sized to protect the internal wiring and outlets. I have many times been in a situation where I used both the 50A and the 15a outlets at the same time with our previous 50a RV and at times I also used a 30A to 20A dogbone adaptor and powered something from the 30a. We have volunteered a lot of places where we were provided a golf cart that we would use one of the pedestal plugs to recharge with no problems at all. There are limits to what you can use but it isn't likely that you would have a problem unless you were trying to run 2 RVs that each had air conditioners from the same pedestal. Being retired from electrical service work I watch such things closely and have never found any issues from what we have used.

 

[Kirk]

I can't do that because I'd over draw on the 50 alone.

A 50a RV power supply is actually 50A for L1 and another 50A for L2, if the two are exactly balanced giving you a total of 100A. In practical application, you seldom are exactly balanced so 80A is more typically what you would max out at, but I don't recall ever hearing of an RV tripping the supply circuit breakers under normal circumstances. Connect your RV to the 50a outlet and it will allow you to use the 30a just fine in the majority of cases. But the entire answer is also dependent upon what the park that you are in has to plug into. Newer parks will be up to code and so you won't have any issues but very often older RV parks have been upgraded by the owner or some other person who doesn't know basic electricity and so connect in unapproved ways and they may not work.

What is it that you are wanting to supply power to from the 30a outlet? Does it actually need the full capacity of that 30A outlet?

 

[drizzamed]

If the pedestal is one that has a circuit breaker for each outlet in that box, you just look at the breakers as they will have the trip point on them. Using both at the same time could run into a limit of the circuit that is supplying the pedestal, but that isn't likely in a park with many pedestals as there would usually be one set of breakers for both legs of power to a larger group of RVs. Circuit breakers in these situations are sized based upon the wire size used to connect things and the breakers on the pedestal are sized to protect the internal wiring and outlets. I have many times been in a situation where I used both the 50A and the 15a outlets at the same time with our previous 50a RV and at times I also used a 30A to 20A dogbone adaptor and powered something from the 30a. We have volunteered a lot of places where we were provided a golf cart that we would use one of the pedestal plugs to recharge with no problems at all. There are limits to what you can use but it isn't likely that you would have a problem unless you were trying to run 2 RVs that each had air conditioners from the same pedestal. Being retired from electrical service work I watch such things closely and have never found any issues from what we have used.

Awesome awesome

If the pedestal is one that has a circuit breaker for each outlet in that box, you just look at the breakers as they will have the trip point on them. Using both at the same time could run into a limit of the circuit that is supplying the pedestal, but that isn't likely in a park with many pedestals as there would usually be one set of breakers for both legs of power to a larger group of RVs. Circuit breakers in these situations are sized based upon the wire size used to connect things and the breakers on the pedestal are sized to protect the internal wiring and outlets. I have many times been in a situation where I used both the 50A and the 15a outlets at the same time with our previous 50a RV and at times I also used a 30A to 20A dogbone adaptor and powered something from the 30a. We have volunteered a lot of places where we were provided a golf cart that we would use one of the pedestal plugs to recharge with no problems at all. There are limits to what you can use but it isn't likely that you would have a problem unless you were trying to run 2 RVs that each had air conditioners from the same pedestal. Being retired from electrical service work I watch such things closely and have never found any issues from what we have used.

Awesome explanation! Last question on the topic, I think... my device is 20amp and I plug it into the 30amp, will the device just draw what is needed from the 30amp or will 30 amps be hammering my device and burn it up? My guess is that it draws what is needed otherwise there would be all kinds of burnt up things on the 50amp service correct? Again, thank you so much for the help!

 

[drizzamed]

I want to keep the wifey happy in the RV and let her run all her normal things without interruption while me and the guys brew 10 gallons of beer from my 225v 20amp kettle. I don't have a hookup from the RV to do this nor would I want to induce that amperage with at least 2 AC if not all 3 running amongst other electronics. So that gave me the idea of either cycling some fuel through the generator and running the RV from it while I use the 50amp or just plugging into the 30amp on the pedestal if it's available.

 

[Kirk]

. my device is 20amp and I plug it into the 30amp, will the device just draw what is needed from the 30amp or will 30 amps be hammering my device and burn it up?

No, it will be just fine. The current rating for any outlet/circuit breaker is the maximum that it can supply and not the minimum. the tag on the device that you have only tells you what it requires or uses. The circuit limit is the most that it will supply. The outlet sends 120V to whatever you connect to it and the thing plugged into it uses what it needs up to that limit. As long as you do not increase the voltage to your device it will draw the amount of current it needs.

Voltage and current are very much related. If you think about a water hose, the amount of gallons per minute supplied is like the amps supplied from your outlet. The psi of your water hose determines how much water it can supply and that is the same as voltage is to your outlet. If you increased the voltage on that outlet to some very high number it would push more than the 20A your device uses and burn it up, but that circuit breaker would still prevent any more than 30A.

 

[drizzamed]

Thank you!

 

[John From Detroit]

Most parks each feed line has a BIG arse breaker 150-250 amps and then 4-5-6 sites (or more) on each breaker.. ONE park I rather like each site has it's own 50 amp breaker.. EACH SITE. so can you use 30+20_50 all at the same time.. YES. but if you go over you might trip the breaker for your feed. and if it is a "Community" feed, not a single site feed. and the master panel is locked, your neighbors (And management) may be...... Unhappy. .