Vertical and horizontal clearance from the overhead lines for building (NESC or NEC)?

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Aru

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My client has a 1500kVA 33.5kV/2.4kV service transformer. Then there is a 2.4kV distribution power line (overhead) from that service transformer that feeds a 500KVA, 2.4kV/480-277V transformer. We are installing a permanent trailer that will be used as office space in the site. I am trying to figure out the minimum vertical and horizontal clearance needed from the overhead lines. The available space for the trailer is limited. I can provide site map if needed.

I am sure that NESC will govern the value of these clearance. But I am looking at Section 23 for clearances and it is very overwhelming. I was hoping someone can guide me as to the right section within 23. I found table 225.61 in NEC 2017 which states that it correlate with NESC. For my purpose, I think 12.5 ft of vertical clearance is the way to go.

Please guide.

Thank you.
 
The 1500 kVA transformer is utility owned. the 2.4 kv line are customer owned. I am not very sure about the service entrance location.
 
Aru said:
My client has a 1500kVA 33.5kV/2.4kV service transformer. Then there is a 2.4kV distribution power line (overhead) from that service transformer that feeds a 500KVA, 2.4kV/480-277V transformer. We are installing a permanent trailer that will be used as office space in the site. I am trying to figure out the minimum vertical and horizontal clearance needed from the overhead lines. The available space for the trailer is limited. I can provide site map if needed.

I am sure that NESC will govern the value of these clearance. But I am looking at Section 23 for clearances and it is very overwhelming. I was hoping someone can guide me as to the right section within 23. I found table 225.61 in NEC 2017 which states that it correlate with NESC. For my purpose, I think 12.5 ft of vertical clearance is the way to go.

Please guide.

Thank you.
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Insulated or Non-Insulated?
 
Since the 2.4kV lines are customer owned and are probably service entrance conductors NEC section 230 Part VIII would apply. Not that it helps much since it does not provide clearance information. An IN in 230.200 does refer to the NESC for the clearances, but INs are not code so it's kind of a punt. I don't think 225.61 would apply here since this is not a branch or feeder. Not being a user of the NESC I can't add any more, but just wanted to point out the relevant NEC sections that apply.
 
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