Distance to 14,000volts to ground

[rbaltes]

Charlie, We are designig a street lighting project with 50 foot metal poles that have each a 23 foot arm that holds the fixture above the state highway. Presently on the same side of the road is an existing 25kv overhead line on wooden poles that is 40 high running parallel to the proposed line of light poles. How far away from the existing 14,000v to ground system should we keep the metal light poles? And, what 2002 code section (2002 is required)did you use?

Thank you for your considerations!

Bob Baltes

 

[charlie]

Re: Distance to 14,000volts to ground

If it is a grounded system, the horizontal clearance without wind displacement is 7? ft and that is from Table 234-1 which is referred to from rule 234C1a. You must also consider wind displacement under rule 234C1b.

In order to apply these rules correctly, I highly recommend consulting with a Professional Engineer whose expertise is in the National Electrical Safety Code. Additionally, you need to determine that the NESC is indeed the Code that covers the placement of the state highway columns. The NESC will be the Code that covers the electric utility if it has been adopted by your state without amendments. The greater of the clearances will be the governing factor if there are two codes.