# rv servcice calculation



## Cirus (Jun 23, 2012)

I've got a 200 amp service available. The customer wants to know if he can get twenty 30 amp rv outlets on this service. Going by the NEC calculation of 3600va x 20 = 72,000va x .45 = 32,400va divided by 240v = 135 amps. So going by those figures the answer is yes. But, we're talking summer in Texas with 100 plus temps and a/c units running constantly. When he first asked me before I had a chance to calculate I told him maybe 13 or 14 tops off the top of my head. 20 seems like alot. Any thoughts?


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## Dennis Alwon (May 9, 2009)

Look at art. 551.73 (C) demand factor FPN-- it states that these demand factors may be inadequate in areas of extreme hot or cold. I would be careful with that one as you suggested


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## backstay (Feb 3, 2011)

You also need 50 amp recept in some numbers. Check the book.


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## frenchelectrican (Mar 15, 2007)

Cirus said:


> I've got a 200 amp service available. The customer wants to know if he can get twenty 30 amp rv outlets on this service. Going by the NEC calculation of 3600va x 20 = 72,000va x .45 = 32,400va divided by 240v = 135 amps. So going by those figures the answer is yes. But, we're talking summer in Texas with 100 plus temps and a/c units running constantly. When he first asked me before I had a chance to calculate I told him maybe 13 or 14 tops off the top of my head. 20 seems like alot. Any thoughts?


As Dennis mention demand factor FPN that will go out of the window in most case like your area when it get hot and many peoples run the RV A/C unit at full load and you will pretty much taxed the system to the limit.

I have few case over in France we did have to replace few spots when they did use the demand caluations and they did not relized that with more modern caravans ( RV's ) do put more load on the system than the old days and few spots of our area the 16 amp P&S ( Pin et sleeve ) power point is pretty much toasted so few went 32 amps verison beside couple super fancy one they used 63 amp verison. ( kinda rare but not suprised it will become common ).

So therefore it will be wiser just go with max rating ( you may end up use the contionous load figures for this one ) that will save some of your headache in long run.

Merci,
Marc


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## Cirus (Jun 23, 2012)

I think this calculation is more realistic when its 105 and no shade. 
12 x 3600 = 43,200 x 1.00 = 43,200 divided by 240 = 180 amps.


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## Cirus (Jun 23, 2012)

backstay said:


> You also need 50 amp recept in some numbers. Check the book.


I did check. This isn't an rv park though.


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