110/220

[Floridajeeper]

Or 120/240...not sure the correct numbers.

Any way the campground we're headed for tonight has only 220V outlets...I am guessing these are 50A hookups.  I did search here and read that all I need is a 30A-50A adapter with no need to worry about burning something up as the adapter only allows 1 pole of the 50A to go through (at 110/120V).

Just want to be clear before I go buy something.

Thanks.

[mike4947]

Yup you are looking for a 50 amp male to 30 amp female dogbone adapter.

[Floridajeeper]

That's what I thought.

BUT now I may have a different dilema.

I have friends already at the CG.  They are telling me the hookups are 220 (according to the CG staff) but they describe to me a 30A plug.  The 'adapter' given by the CG is a 30A male to a 15A female...??

[wynot]

Or 120/240...not sure the correct numbers.
 
Any way the campground we're headed for tonight has only 220V outlets...I am guessing these are 50A hookups. I did search here and read that all I need is a 30A-50A adapter with no need to worry about burning something up as the adapter only allows 1 pole of the 50A to go through (at 110/120V).
 
Just want to be clear before I go buy something.
 
Thanks.

I don't think I have ever seen a 240 V outlet in an American campground.  Europe, sure.  Usually, what one finds is 15, 20, 30Amp, and sometimes 50A 120 V outlets.

[AustinBoston]

50A 120 V outlets.

Where do you camp?

I've never seen any such thing at an American campground.  I've seen 120V 15A, 20A, and 30A, and 240V 50A, but never a 120V 50A.

On a different note, I do not believe a 50A to 30A adapter for a pop-up is safe unless it contains it's own 30A breaker.  The pop-up does not have a master breaker because it relies on the campground's 30A breaker.  But with an adapter, you could overload the cable by a wopping 67% before the 50A post breaker would trip.

Austin

[ScoobyDoo]

Where do you camp?

I've never seen any such thing at an American campground.  I've seen 120V 15A, 20A, and 30A, and 240V 50A, but never a 120V 50A.

On a different note, I do not believe a 50A to 30A adapter for a pop-up is safe unless it contains it's own 30A breaker.  The pop-up does not have a master breaker because it relies on the campground's 30A breaker.  But with an adapter, you could overload the cable by a wopping 67% before the 50A post breaker would trip.

Austin

If  the adaptor picks up one leg of a 50AMP 220V service the PUP wouldn't be protected by a 25AMP breaker?

[AustinBoston]

If  the adaptor picks up one leg of a 50AMP 220V service the PUP wouldn't be protected by a 25AMP breaker?

No.  The breaker is for 50 amps at 240 volts.  There are two hot wires with a voltage between them of 240 volts.  The neutral wire is halfway between the two, so you also get the equivalent of two 120 volt, 50 amp circuits.

If I want 240 volts at 50 amps, I connect to both hot wires and ignore the neutral (I don't need the neutral for anything except 120V), so for 50 amps at 240 volts, both hot wires have to be able to carry 50 amps.  If I connect one side of my circuit to the neutral for a 120V circuit, the main breaker is still rated at 50 amps, and I can get 50 amps at 120 volts.

In practice, most pop-ups have a single 15 amp breaker and a single 20 amp breaker, so the most that will go through the main cable is 35 amps (any more than that and one or both of the breakers in the pop-up will trip), but that is still more than the cable is rated for.

Austin

[Floridajeeper]

Turned out I needed nothing...just plugged the camper in as it was 125V 30A.  The  CG manager swore all up and down it was 240...until I showed them the inside of their own hookup boxes...where it clearly shows 125V 30A.

Thanks for all the info though.  

[wynot]

No. The breaker is for 50 amps at 240 volts. There are two hot wires with a voltage between them of 240 volts. The neutral wire is halfway between the two, so you also get the equivalent of two 120 volt, 50 amp circuits.
 
If I want 240 volts at 50 amps, I connect to both hot wires and ignore the neutral (I don't need the neutral for anything except 120V), so for 50 amps at 240 volts, both hot wires have to be able to carry 50 amps. If I connect one side of my circuit to the neutral for a 120V circuit, the main breaker is still rated at 50 amps, and I can get 50 amps at 120 volts.
 
In practice, most pop-ups have a single 15 amp breaker and a single 20 amp breaker, so the most that will go through the main cable is 35 amps (any more than that and one or both of the breakers in the pop-up will trip), but that is still more than the cable is rated for.
 
Austin

So you're saying that this is the equivalent of 100 A at 120V?  I'm not necessarily saying no way, but I find it hard to believe that campgrounds are willing to put that kind of juice out there.  They are already running shared loads for Class As with two ACs (switching units so that only one runs at a time), so that they can run off of 30 A 120V if necessary.

[mike4947]

Yup, 50 amp service consists of TWO 120 volt legs. It is rated at 50 amps @ 240 volts. This consists of two 120 volt hot leads, a neutral lead, and a ground. Each hot leg will provide 50 amps @ 120 volts.
Some class A units have up to 4 rooftop AC's; or twin basement heat pumps, plus electric 240 volt water heaters and even electric 240 volt cook tops.
Believe it or not there is a lot of talk about upping service to 70 amp @ 240 volts at some higher end RV parks.
Until about 5-6 years ago even high end RV's came with a main service panel with a twin 50 amp main breaker but with spacing between the busses so you could not use a 240 volt breaker only 120 volt breakers. So there was a lot of misunderstanding about it being 120 volt or 240 volt.
Now it's fairly common on higher end RV's to have panels that allow and use 240 volt breakers for appliances.

[AustinBoston]

So you're saying that this is the equivalent of 100 A at 120V?  I'm not necessarily saying no way, but I find it hard to believe that campgrounds are willing to put that kind of juice out there.  They are already running shared loads for Class As with two ACs (switching units so that only one runs at a time), so that they can run off of 30 A 120V if necessary.

That may sound huge, but it's only three times as much power for a Class A (50A x 240V = 12,000VA) as for a pop-up (30A x 120V = 3,600VA).

When you compare the Class A (with two, three, or four a/c units, microwave, electric stove [maybe], electric washer & dryer [maybe] much larger fridge) with the pop-up (one a/c [maybe] and a microwave [maybe], and a little tiny fridge) it's remarkable that the Class A can get by on 50A 240V.

At a lot of campgrounds, those class-A's pay a premium.

Austin