Design questions for 5kV Transmission Lines

[jliu1]

I am currently working on a 5kV distribution system which consists of 6 miles of 5kV transmission lines. The load is about 200Amps. Can somebody help by telling how many poles and any other equipment I need? Or a rough number of cost per miles would be greatly helpful. Appreicate any input.

 

[Dumbo2929]

The first thing is that 5kV is not a transmission voltage, it is a distribution voltage. Transmission and distribution construction is very different.

 

[wareagle]

5 KV 200 amps for a distance of 6 miles. That's a long way using 5 kv. I assume you mean 4.16 kv.
Some things you need to know.
1 conductor size AL. 1/0 = 230a, 2/0 = 270a 3/0 = 300a.

2 Voltage drop per mile for 2/0 = 178 volts/mile @ 200 amps.
Est VD = Amps (R Cos A + X Sin A)

3 Pole ht. Pole height is generally 40 ft and spans can be about 350 ft depending on the size of the conductor and ground clearance required. Ground clearance depends on whether you are over rural or urban terrain.

4 Pole class is determined by the area you are based on wind and ice loading. Class refers to the diameter of the pole at its base.

5.Hardware. Are you using wood cross arms are fiberglass
supports?

6 What type of line protection do you have? Fuses, Line OCR
or other.

 

[wareagle]

jliu1

How about a reply to your question.

 

[jghrist]

You might find the US Rural Utility Service (RUS) document 1728F-804 Specifications and Drawings for 12.5/7.2 kV Line Construction (4/21/2005)of use. It can be downloaded at

http://www.usda.gov/rus/electric/bulletins.htm

 

[wbd]

You should also get a copy of the National Electric Safety Code. It can be obtained thru the IEEE. It will contain alot information on clearances, grades of construction, strength requirements, line insulation, etc.