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High Voltage Transmission Lines Over Building?

eyan50495

Registered User
Joined
May 18, 2020
Messages
71
Location
Locust Valley, NY
Hi,

A contractor I've worked with on a previous project just asked me if I know anything about this subject. I haven't encountered it but I can't find anything on it from a building code or fire code point of view (just OSHA).

A multifamily mid-story building in NYS is being constructed (approved already) and is being built under high voltage transmission lines. The clearance is only 5' from the lowest wires to the top of the roof.

To me this sounds like a dangerous fire hazard let alone a problem with OSHA on the construction of it.

Does anyone know more information on this subject? I'm surprised their engineer did not catch it....

Just curious at this point.
 
A question for whoever owns the lines???

Yes a work area problem, cant say much more
 
OK Update:

Turns out it is not a high transmission line but a regular pole - the contractor did not use the proper terms. I'd imagine they simply reach out to the local power company and open a dialogue?
 
Here in California the power companies have an easement under primary and secondary distribution lines. That causes people to consult with the power company and that would most likely prevent a structure as close as 5' to a distribution line.
 
The utility companies should provide some guidance in these situations. Depending on voltages in the transmission lines you could have nice arcing and sparking. We had a parking lot that required the light poles to be less than 12 ft tall due to the transmission lines overhead. If I remember correctly we had to stay 30 ft away from the lines.
 
NFPA 70 230.24(A) Exception No. 1

IRC 2015 (maintained by NFPA)

E3604.2.1 Above roofs.

Conductors shall have a vertical clearance of not less than 8 feet (2438 mm) above the roof surface. The vertical
clearance above the roof level shall be maintained for a distance of not less than 3 feet (914 mm) in all directions from
the edge of the roof. See Figure E3604.2.1. [230.24(A)]
Exceptions:
1. Conductors above a roof surface subject to pedestrian traffic shall have a vertical clearance from the roof surface in

accordance with Section E3604.2.2. [230.24(A) Exception No. 1]

E3604.2.2 Vertical clearance from grade.

Overhead service conductors shall have the following minimum clearances from final grade:

1. For conductors supported on and cabled together with a grounded bare messenger wire, the minimum vertical
clearance shall be 10 feet (3048 mm) at the electric service entrance to buildings, at the lowest point of the drip loop of
the building electric entrance, and above areas or sidewalks accessed by pedestrians only. Such clearance shall be
measured from final grade or other accessible surfaces.

2. Twelve feet (3658 mm)—over residential property and driveways.

3. Eighteen feet (5486 mm)—over public streets, alleys, roads or parking areas subject to truck traffic. [(230.24(B)(1),
(2), and (4)]
 
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