Stay within Right of Way under which load cases.
Stay within Right of Way under which load cases.
(OP)
In thread608-259312: Structure Deflection it was mentioned that the NESC requires wires to stay within the the Right of Way under blowout conditions. What section is that specified in?
In sections 230-234 I see only references to the clearances between wires and various objects, but no mention of property rights. I have come across 4 different situations, but haven't found a code reason to justify any of them. Does anyone apply something besides option 2?
1. Keep the wires on your ROW under nominal conditions.
2. Keep the wires on your ROW under blowout conditions.
3. Keep the wires on your ROW under all conditions.
4. Keep the wires on your ROW under all conditions, with enough clearance that some could put a building on the property line and still meet rule 234 clearances.
In options 1 to 3, it seems like you are interfering with the adjacent property owners right to fully utilize their land.
In sections 230-234 I see only references to the clearances between wires and various objects, but no mention of property rights. I have come across 4 different situations, but haven't found a code reason to justify any of them. Does anyone apply something besides option 2?
1. Keep the wires on your ROW under nominal conditions.
2. Keep the wires on your ROW under blowout conditions.
3. Keep the wires on your ROW under all conditions.
4. Keep the wires on your ROW under all conditions, with enough clearance that some could put a building on the property line and still meet rule 234 clearances.
In options 1 to 3, it seems like you are interfering with the adjacent property owners right to fully utilize their land.





RE: Stay within Right of Way under which load cases.
Option 2 would certainly help with section 218 vegetation issues. Option 3 is impossible to achieve, since all conditions include airliner crashes, nuclear attack, and so forth. And option 4 seems like a good idea, since NESC is maintenance code that obligates the utility to maintain clearances no matter what the adjoining landowner might do on his land.
RE: Stay within Right of Way under which load cases.
Option 4 sounds like a great plan, but for distribution and subtransmission on street ROW, it is already pretty difficult just to meet option 2.
RE: Stay within Right of Way under which load cases.
Won't it be more difficult to move the line when the adjacent owner starts building? The required setbacks may not be sufficient to maintain clearance.
RE: Stay within Right of Way under which load cases.
NESC Rule 230 I. says:
Maintenance of clearances and spacings
The clearances and spacing required shall be maintained at the values and under the conditions
specified in Section 23 of the applicable edition. The clearances of Section 23 are not intended to be
maintained during the course of or as a result of abnormal events such as, but not limited to, actions
of others or weather events in excess of those described under Section 23.
NOTE: See Rule 13 to determine the applicable edition.
Figure 233-2 Point D specifies Final Sag, No Ice and a 6 PSF wind on the bare conductor at 60° F.
Section 234A2 says:
Horizontal clearances (with wind displacement)
Where consideration of horizontal displacement under wind conditions is required, the wires,
conductors, or cables shall be considered to be displaced from rest toward the installation by a
290 Pa (6 lb/ft2) wind at final sag at 15 °C (60 °F). The displacement of a wire, conductor or
cable shall include deflection of suspension insulators. The displacement of a wire, conductor,
or cable shall also include deflection of a flexible structure if the highest wire, conductor, or
cable attachment is 18 m (60 ft) or more above grade.
So the NESC requires that the wire when blowing out must consider the deflection of the catenary, the suspension insulator and the structure and maintain code clearance at 6 psf and not for the extreme wind from Rule 250C (abnormal event).
This is not to say that if a conductor blows out of the ROW during a hurricane and contacts a building and burns it down, you won't get sued by the owner.
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I have been called "A storehouse of worthless information" many times.
RE: Stay within Right of Way under which load cases.
RE: Stay within Right of Way under which load cases.
I am under the impression that on the fairly rare occasion someone does want to build near our lines, they have paid us to relocate or raise the lines. While easy and more difficult are not directly related to money, having someone elses money to spend eases the burden a bit ;)
RE: Stay within Right of Way under which load cases.
The non-utility adjacent property owner, not subject to an easement or ROW agreement, and not subject to NESC is not obligated to pay anything.
RE: Stay within Right of Way under which load cases.
The Rural Utilities Services recommends transmission ROW width to be wide enough to accomodate conductor blowout under NESC rule 250C Extreme Wind and still provide clearance to buildings. No distinction is made for rural or urban areas.
RE: Stay within Right of Way under which load cases.
I have heard (not sure where) that some states allow utilities to trim trees outside their ROWs on private property. We have always trimmed trees at the edge of the ROW straight up, but the new thought is you go straight up to some elevation and then at an angle into the private property.
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I have been called "A storehouse of worthless information" many times.