RV park overload

[jotw]

Good afternoon, all. I am getting into another RV park and a question was posed that I am stumped by. While discussing the size service needed for 48 spots (all 50A) I told the project manager the RV spots alone will require 800A of service (120/240.) The demand factor is 41% and that comes to 787A. So, he asked after doing his own math, "What happens when the park is full and every RV is blasting the AC with windows and doors open, cranking stereos, and everybody is taking showers with their electric on demand heaters?" In other words, every RV in the park is being a big power hog. I feel sure that the demand factor takes into consideration total connected load, but, I'm wondering if anyone can share some insight? I was trying to find something online that addressed what a big RV might pull (in terms of amps) but haven't found much yet. Thank you in advance.

 

[zbang]

What happens when all 48 spaces are pulling even 30a a leg full-time? That's easy, the main trips; or at least it should. (Just like we derate wiring for high ambient temps, like on a roof, I don't think I'd count on that demand factor being close to reality on a hot Texas afternoon.)

Better question is whether the customer is willing to pay for enough infrastructure to support that load without the 41% demand factor.

Does anyone have actual RV park load data? (I don't.)

There are a number of older threads on this forum, too.

I also found an interesting write up (although it's for Canada and not directly related to the question)-
http://campgrounds.pgtto.com/wp-content/uploads/2014/07/Campground-Power-Distribution.pdf

 

[jotw]

That was actually another question that I had (re. the main tripping.) Do adjustable trip settings only apply to motor loads?? 240.6 (B) or (C)??

A part of me says to bid it as the architect (from Michigan) drew it and they get what they get (800A). Another part of me says to bid it with a bigger service knowing that if I don't, I'll get the call to "fix it" when the park is totally without power because the customer (in the desert) didn't want to pay for reality. If I can find some good data (as zbang asked) then I can determine IMO where to go with it.

Thanks!

 

[jotw]

thanks for the link too!

 

[augie47]

That was actually another question that I had (re. the main tripping.) Do adjustable trip settings only apply to motor loads?? 240.6 (B) or (C)??

A part of me says to bid it as the architect (from Michigan) drew it and they get what they get (800A). Another part of me says to bid it with a bigger service knowing that if I don't, I'll get the call to "fix it" when the park is totally without power because the customer (in the desert) didn't want to pay for reality. If I can find some good data (as zbang asked) then I can determine IMO where to go with it.

Thanks!

"Adjustable trip" rules apply to overcurrent devices in general.
If you are bidding it and have architect (engineer) drawings and the drawing meet Code I would suggest you bid it as shown to be competitive. You can certainly provide an alternate "suggested" bid.
I know our POCOs have begun increasing their transformer sizes at RV parks as the public's idea of "roughing it" has evolved. I would not be surprised to see some changes in future Code cycles.

 

[texie]

Good afternoon, all. I am getting into another RV park and a question was posed that I am stumped by. While discussing the size service needed for 48 spots (all 50A) I told the project manager the RV spots alone will require 800A of service (120/240.) The demand factor is 41% and that comes to 787A. So, he asked after doing his own math, "What happens when the park is full and every RV is blasting the AC with windows and doors open, cranking stereos, and everybody is taking showers with their electric on demand heaters?" In other words, every RV in the park is being a big power hog. I feel sure that the demand factor takes into consideration total connected load, but, I'm wondering if anyone can share some insight? I was trying to find something online that addressed what a big RV might pull (in terms of amps) but haven't found much yet. Thank you in advance.

In an area like you are in, I think it is wise to heed the Informational Note that follows 551.73.