horizontal clearance around privately owned 12kv power line

[wsbeih]

Working on an industrial facility which has it is own power distribution pf 12kv lines (bare Al cables) on wopdren poles, typically 45' high. They get power from local power utility at some point on facility entrance.
The project require installing new steel pipe rack nearby these power poles within 1 foot only.
Per my code and regulation searches both NESC and OSHA.
Require 10 foot clearances.
My questions are:
1- does these requirements apply to both utility poles and privately owned poles?
2- would replacing bare conductors with sheilded ones, releief from such requirements?
I need specific code/standard references from ower forum experts.
Thanks in advance for your help.

 

[wsbeih]

One more clarification please.
Typically this 10' clearance are from the actual pole or the energized conductors?

 

[topgone]

Working on an industrial facility which has it is own power distribution pf 12kv lines (bare Al cables) on wopdren poles, typically 45' high. They get power from local power utility at some point on facility entrance.
The project require installing new steel pipe rack nearby these power poles within 1 foot only.
Per my code and regulation searches both NESC and OSHA.
Require 10 foot clearances.
My questions are:
1- does these requirements apply to both utility poles and privately owned poles?
2- would replacing bare conductors with sheilded ones, releief from such requirements?
I need specific code/standard references from ower forum experts.
Thanks in advance for your help.

Which table were you looking at when you said 10' clearance? Clearance from live wires can be found in Table 124-1 (NESC).

 

[Iron_Ben]

Working on an industrial facility which has it is own power distribution pf 12kv lines (bare Al cables) on wopdren poles, typically 45' high. They get power from local power utility at some point on facility entrance.
The project require installing new steel pipe rack nearby these power poles within 1 foot only.
Per my code and regulation searches both NESC and OSHA.
Require 10 foot clearances.
My questions are:
1- does these requirements apply to both utility poles and privately owned poles?
2- would replacing bare conductors with sheilded ones, releief from such requirements?
I need specific code/standard references from ower forum experts.
Thanks in advance for your help.

I have pasted at the end two paragraphs from the IEEE Standards Association. The second tells us that a system at an industrial complex is covered.

My recollection is that the required horizontal clearance in this case is "only" 7.5 feet and not 10. Still, that's a far cry from one foot, which is a very bad idea. I'd look it up but my copy of the NESC is in a storage locker at present, but I think this is from Table 234. I don't know if going to a covered conductor changes things, but I don't think it does. For me personally it does not. I wouldn't get within 7.5 (or 10) feet of this line with it energized nor would I let anyone under my supervision get that close. And I would be derelict in my duty if I allowed a pipe rack to built within 1 foot of the line. Grossly derelict. In fact if there will be cherry pickers or mobile cranes in the immediate vicinity, then 10 feet sounds like insufficient clearance.

Oh, and these clearance numbers are always from/to the conductors and not the poles.

The NESC is revised every 5 years. The purpose of the NESC is the practical safeguarding of persons during the installation, operation, or maintenance of electrical supply and communication lines, equipment, and associated work practices employed by a public or private electric supply, communications, railway, or similar utility in the exercise of its function as a utility.

It covers similar systems under the control of qualified persons, such as those associated with an industrial complex or utility interactive system. It is not intended as a design specification or as an instruction manual.

 

[wsbeih]

I have pasted at the end two paragraphs from the IEEE Standards Association. The second tells us that a system at an industrial complex is covered.

My recollection is that the required horizontal clearance in this case is "only" 7.5 feet and not 10. Still, that's a far cry from one foot, which is a very bad idea. I'd look it up but my copy of the NESC is in a storage locker at present, but I think this is from Table 234. I don't know if going to a covered conductor changes things, but I don't think it does. For me personally it does not. I wouldn't get within 7.5 (or 10) feet of this line with it energized nor would I let anyone under my supervision get that close. And I would be derelict in my duty if I allowed a pipe rack to built within 1 foot of the line. Grossly derelict. In fact if there will be cherry pickers or mobile cranes in the immediate vicinity, then 10 feet sounds like insufficient clearance.

Oh, and these clearance numbers are always from/to the conductors and not the poles.

The NESC is revised every 5 years. The purpose of the NESC is the practical safeguarding of persons during the installation, operation, or maintenance of electrical supply and communication lines, equipment, and associated work practices employed by a public or private electric supply, communications, railway, or similar utility in the exercise of its function as a utility.

It covers similar systems under the control of qualified persons, such as those associated with an industrial complex or utility interactive system. It is not intended as a design specification or as an instruction manual.

Thanks Iron_Ben for your valuable input.
IF those conductors are 20' higher than the pipe rack which is installed 1' away from the power pole, then wouldn't this satisfy all minimum clearances? regardless 7.5,10 up to 20 feet. You will have 20' sphere clearance around the conductors. Is my analogy correct?

 

[Iron_Ben]

Thanks Iron_Ben for your valuable input.
IF those conductors are 20' higher than the pipe rack which is installed 1' away from the power pole, then wouldn't this satisfy all minimum clearances? regardless 7.5,10 up to 20 feet. You will have 20' sphere clearance around the conductors. Is my analogy correct?

Yes, I believe that it is. I think NESC Table 232 would apply in this case so check that to be sure. But as I noted above if you know that mobile cranes or similar equipment will be in the area loading pipes on and off the rack, that adds a wrinkle that might tell you that you should go beyond NESC minimums. If somebody contacts the line in the future and is killed or badly burned, you'll have to justify every decision you ever made. We went through such scenarios every so often and all the second guessing and time spent with lawyers sucked, to say nothing of the pain of the individuals burned and/or killed and their families.

Putting this high voltage line underground won't be cheap and might not even be feasible. But we tried to put safety first and when indicated, we did exactly that.

 

[iwire]

Working on an industrial facility which has it is own power distribution pf 12kv lines (bare Al cables) on wopdren poles, typically 45' high. They get power from local power utility at some point on facility entrance.
The project require installing new steel pipe rack nearby these power poles within 1 foot only.
Per my code and regulation searches both NESC and OSHA.
Require 10 foot clearances.
My questions are:
1- does these requirements apply to both utility poles and privately owned poles?
2- would replacing bare conductors with sheilded ones, releief from such requirements?
I need specific code/standard references from ower forum experts.
Thanks in advance for your help.

The OSHA rules apply to any live conductors regardless of ownership or source of the power.

 

[bob]

I have included pictures of using cross arms to clear the hazard. This is a common method used by utilities. You may have to
install a pole near the location the pipe racks. You can purchase 8 ft. arms for this purpose.

 

[wsbeih]

Thank you all for your help.