RV park calculations

[quinn77]

Hey forum!
I've been contracted to design and oversee installation of an addition to a relatively new RV park. The addition calls for 13 new pedestals and area lighting. Being this is my first run with an RV park, I've come to the forum for advice. I don't have my codebook handy, but I recently read through the article pertaining to RV parks, and my first calculation said I could feed 17 pedestals with a 200 amp service. The source is single phase 240 volt. The pedestals are 50A 240v, 30A 120v, and 20A 120v combo pedestals. The FPN also gave a vague suggestion that in areas of extreme heat or cold, that corrections may need to be made for the increased demand from heating and air conditioning. I am on the Texas Gulf Coast. HOT!!! The existing install doesn't seem to be up to code, but like I said I don't have me book handy. I was able to get into pedestal 11 today, and found it was fed with #2 AL, and #4 AL was leaving feeding #12. The main breaker for the series of pedestals is 200A. Isn't this a violation? Also, the previous electrician only pulled 2 ungrounded and a grounded conductor from the main, driving ground rods and grounding the neutral at each pedestal. The pedestals have sub-meters, but the main feeders are metered at the main. The owner of the park reads the sub meters and charges accordingly. These metered pedestals would not be considered services by definition. Thanks for any clarity on this matter.

 

[Dennis Alwon]

It is hard to say without knowing the install. There may be a tap rule used. What size breaker is at the pedestal with the #2-- 100 amp? 50amp? Sorry I am off to bed now

 

[quinn77]

There is a string of 50A/30A/20A pedestals fed from a 200Amp Service. The service is a 400 amp meter with 2-200 amp mains feeding the strings of combo pedestals, containing a 50A breaker, 30A breaker, and 20A breaker. 25 feet lateral between pedestals.

 

[Smart $]

There is a string of 50A/30A/20A pedestals fed from a 200Amp Service. The service is a 400 amp meter with 2-200 amp mains feeding the strings of combo pedestals, containing a 50A breaker, 30A breaker, and 20A breaker. 25 feet lateral between pedestals.

I think what Dennis is alluding to is if pedestal #12 is last in the string, it can use a smaller conductor under the tap rules of 240.21.

However, the #2 AL feeding pedestal #11 is likely a violation.

The grounding technique is in violation of recent code cycles, but if installed under cycle where an EGC was not required with outside feeders, it may be compliant. I believe it changed in the 2005 edition... ???