Running 21KV in overhead conduit - NEC 225.60 & 225.61

[Machiavelli999]

For a project at an industrial site, it was suggested to me to route a medium voltage feeder in conduit along the side of a building instead of running it underground due to the difficulty trenching in the location would entail.

I thought this was feasible until I read 225.60 & 225.61. It does not seem that routing along sides of buildings or roofs are allowed as the required clearances would be violated. Any thoughts on this? I know there are 4.16KV feeders used for chillers and even data center distribution. How are those not in violation of these clearences? Is it because they are in conduit? Do the clearances only apply to conductors in free air?

 

[electrofelon]

For a project at an industrial site, it was suggested to me to route a medium voltage feeder in conduit along the side of a building instead of running it underground due to the difficulty trenching in the location would entail.

I thought this was feasible until I read 225.60 & 225.61. It does not seem that routing along sides of buildings or roofs are allowed as the required clearances would be violated. Any thoughts on this? I know there are 4.16KV feeders used for chillers and even data center distribution. How are those not in violation of these clearences? Is it because they are in conduit? Do the clearances only apply to conductors in free air?

The wording could be better, but I can't imagine those sections are intended to cover cable assemblies in raceways.

 

[augie47]

The wording could be better, but I can't imagine those sections are intended to cover cable assemblies in raceways.

I would agree, It would have been better if they had worded it like 225.19.
Those Sections surely address open conductors and cables not in a raceway.

 

[don_resqcapt19]

The language specifies clearances "to conductors". Such rules do not apply to conductors in a raceway or in a jacketed cable.

 

[electrofelon]

The language specifies clearances "to conductors". Such rules do not apply to conductors in a raceway or in a jacketed cable.

Yes but there are still conductors there, they need to have better wording

 

[electrofelon]

The language specifies clearances "to conductors". Such rules do not apply to conductors in a raceway or in a jacketed cable.

Would it be so hard for them to state that in those sections?