Campground hook-ups: 30 amp, 50 amp, what's the difference?

[440charlie]

Sent: 8/22/2004

HI All  just wondering why some campgrounds have 30 or 50 amp hookups My old girl takes a 30 amp jolt;   Will 50amp hurt anything and do I need a special plug??

Getting ready for maiden voyage week after labor day  Short trip 45miles each way stay over nite Hopefully catch a fish or two.   And rather than run the jenny we will hook up to elec. IE 30--50??   Thanks for input    Charlie P.

[Oz]

Sent: 8/22/2004

THANK YOU FOR POSTING THIS QUESTION!  I've wondered this EVERY time I go to a campground and I ALWAYS forget to ask it!

I have noticed that the plug IS different but, I don't know if an adapter is ok to use.  Seems it would fry our 30amp systems but, it'll be great to finally get this one answered as I'm sure there simply must be more folks out there that know as little about this as I do. - Sob

[denisondc]

Sent: 8/22/2004

That amperage number only means the total current available - the capacity. The 50 amp service cant damage a 30 amp system or a 15 amp system. If your shore power cord has a 30 amp plug, it will plug into a 30 amp outlet. Your appliances will draw only the current they need. All this at 110 volts. If you are in a campground that has 50 amp service, you would need an adapter for your 30 amp shore power cord to fit the 50 amp outlet. And you would still only be drawing whatever your appliances normally would. For mine that is 12 amps for the roof a.c, 1.5 for the fridge, and about 1 amp more to power the converter. I would be using only 14.5 amps, regardless of the amperage of the service. Now if you had a late model 36 foot coach with 2 roof a.c.s and an electric clothes dryer, 1000 watt microwave, and a hair dryer, all going at once - you would need to have the 50 amp service, cause you would pop the circuit breaker on 30 amp service.

[Oz]

Sent: 8/22/2004

Thanks again for a quick response, Dave!  We just came from a campground where the 3 point hook-ups had only 50 amp service and I was afraid we couldn't get one of those sites because of it. 

That also settles another question I had along the same lines: If all the campgrounds started up-grading to 50 amp, would our 30 amp systems be going the way of the dinosaur and would we have to do a 50 amp upgrade... well, glad to hear... no,...only if we want to. - Sob

[DanD2Soon]

Sent: 8/22/2004

Almost all of our Classics have a 3 prong 30 Amp 110 RV shoreline plug and those plugs are correct for our breaker panels and shoreline wire sizes and should be left alone / original. Without going into the details, the 50 AMP receptacles are 240 Volt, 4 prong and while some of our membership have the ability to correctly match their shoreline wires to the correct three prongs, some don't.

The safest way to connect to other Amperage receptacles like 50 AMP or even 15 AMP is to use a "Dogbone" adapter. All the RV and Travel Trailer shops have them for between $10 & $15 each. They are essentially a six in extension cord with a male plug on one end and a female plug on the other making them look a little like a black "dogbone" and are available in four configurations:
- 15 AMP to 30 AMP *
- 15 AMP to 50 AMP
- 30 AMP to 50 AMP
- 50 AMP to 30 AMP *

* I carry these two and store them in my shoreline storage compartment. Leaving your wiring alone and carrying two "dogbones" is really the safest most versatile and convenient way to be prepared for any size of site service. If you have no choice other than a 15 Amp supply, like when visiting at friends and relatives or even at home, you just have to be careful with your usage and conserve. Other than that, you're ready for anything you find!

Later,
DanD

[denisondc]

Sent: 8/23/2004

So to be prepared I will figure on getting the adapter that goes from the 30 amp plug on my shore power cord, to adapt to a 50 amp campground outlet. I already have the 15amp to 30amp adapter. With our 13k btu roof a.c. and not having other heavy loads, its easy for us to run from a normal duplex outlet at campgrounds and our relatives driveway.

[DanD2Soon]

Sent: 8/23/2004

That's right, Dave,

And, as you've probably already found with your 15 to 30 amp adapter, most garage and weatherproof duplex receptacles are wired with 12 gauge wire on 20 amp breakers even though they accept a 15 amp plug, so there's actually a slight "cushion" available (5amps) to allow for the little surges that occur when an appliance (A.C./Micro/Frig) "Kicks In" or to offset the voltage drop of an extension cord if you MUST use one.

Later,
DanD

[DanD2Soon]

Sent: 8/23/2004

SOB,

Just as I hit the enter key to send that last message - a moment too late to "get it back." - a couple of thoughts "flashed" into mind...both "sparked" by Ian's "Tip of the week" thread of a couple months ago.

1st - When you index this important little thread for the message search, maybe you should add the "Tip" flag to it. I went to the search and could not find its ever having been discussed before - Great resource; Your search page!

2nd - Safety - Has to do with extension cords and shorelines (just Fancy Ext. Cords.) I'll post it here because it really applies to this topic and then repost it with its' own title & "Tip" flag to make it easy to find with a search.

SUBJECT: MELT DOWN - Extension cords and shorelines can get very hot and even melt when used in a coiled position - even when being used below their rated amperage! It has to do with a transformer action that occurs between the turns of wire in a coil under load that produces heat - not so noticeable at fractional draws like 5 amps in a 20 amp rated extension cord - but under the right/wrong conditions, a 12 amp load on the same 100' cord wrapped around a cord reel might melt the insulation right off it! Same sort of thing can occur with your shoreline, though not usually as severe, if you only pull out the four feet you need to reach the campground service box and leave the rest "neatly" coiled in the compartment under your bed. Ever wonder why the shoreline stowed in the air conditioned RV was "warm?"

What to do:
- Don't use an extension cord if you can avoid it.
- If you have to, then use the shortest one you can find &
- DON'T coil it - Same for your shoreline - Pull it all out! &
- Lay it out under or alongside the RV in long, easy loops.

When stowing the shoreline:
- Feed it back into the compartment in random "easy" loops or "criss-crossed" "figure eights"
- Don't coil it neatly and stick it in the compartment! (Especially important if your shoreline accesses your Genset by plugging into a Genset receptacle inside the same compartment.)

Hope all this saves someone some trouble or at least prevents the scare that comes from smelling burning rubber...

Thanks from me too, Charlie - Good Question!
DanD

[440charlie]

Sent: 8/23/2004 9:14 PM

HI ALL AGAIN  I am glad I wasn't the only one that benefited from all the great feed back as to amp's [30-50]   Like the thought as to pull cords all the way out,  wouldn't want to burn my toosh when sleeping.haha.  Thanks again as to all great responds     Charlie P.