ELECTRICAL WIRES HEIGHT REQUIREMENTS
- Thread starter kbrinman
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bphgravity
Senior Member
- Location
- Florida
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
See Article 230.24 of the 2002 NEC for serviceclearance requirements.
You may also need to refer to the National Electrical Safety Code depending on the type of wiring your are concerned with.
You will have to check with your local building department to learn if there are local admendments or changes to the NEC specifications.
See Article 230.24 of the 2002 NEC for serviceclearance requirements.
You may also need to refer to the National Electrical Safety Code depending on the type of wiring your are concerned with.
You will have to check with your local building department to learn if there are local admendments or changes to the NEC specifications.
pierre
Senior Member
- Location
- Westchester County, New York
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
Also refer to 225.18 for outside branch circuits and feeders
Pierre
Also refer to 225.18 for outside branch circuits and feeders
Pierre
websparky
Senior Member
- Location
- Cleveland, Ohio
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
kbrinman,
The answer to the question you asked;
Dave
[ July 11, 2003, 06:58 PM: Message edited by: websparky ]
kbrinman,
The answer to the question you asked;
Hope this helps,
Dave
[ July 11, 2003, 06:58 PM: Message edited by: websparky ]
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
websparky: You are correct I misread the dimension. The Local inspector enforcing the NEC dimension will have a hard way to go.
A service drop should not be in the NEC.
The dimension established by the NESC is an engineered calculation based on height of standard power poles. 18 feet may be possible at the feed point, but 15 feet is more likely at the sag point.
Remember the power company will not install any line higher than necessary.
On the same subject...I hold the record for installing the worlds highest above ground power line. The line was 10,000 feet above the earth, on two by four poles.
websparky: You are correct I misread the dimension. The Local inspector enforcing the NEC dimension will have a hard way to go.
A service drop should not be in the NEC.
The dimension established by the NESC is an engineered calculation based on height of standard power poles. 18 feet may be possible at the feed point, but 15 feet is more likely at the sag point.
Remember the power company will not install any line higher than necessary.
On the same subject...I hold the record for installing the worlds highest above ground power line. The line was 10,000 feet above the earth, on two by four poles.
luke warmwater
Senior Member
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
Bennie, wasn't that 'above Sea Level'?
Bennie, wasn't that 'above Sea Level'?
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
Hi all, I was recently travelling to Columbus and happened to see transmission towers in the Megavolt range not sure of the exact voltage. Point is at the sag between these towers they couldnt have been more than 20' from the ground! I actually stopped and surveyed the surroundings. Over the road If two or three semis went under them at once they would move. Out over the corn field the lines werent even as high as the aprox 20 acres of trees that ran adjacent to them. These arent red woods either they are you typical NW Ohio deciduous timbers. Every drop of the 3phases were in arrays of 4 cables with square seperators keeping the 4 wires from tangling. Arent these lines actually supposed to be at a hieght greater than that of standard secondary transmission lines? I just worry that some unsuspecting farmer will snag this some day when he is shooting across the field with his cultivator extensions raised.
Hey Bennie, 10,000' I hope it payed good.
Hi all, I was recently travelling to Columbus and happened to see transmission towers in the Megavolt range not sure of the exact voltage. Point is at the sag between these towers they couldnt have been more than 20' from the ground! I actually stopped and surveyed the surroundings. Over the road If two or three semis went under them at once they would move. Out over the corn field the lines werent even as high as the aprox 20 acres of trees that ran adjacent to them. These arent red woods either they are you typical NW Ohio deciduous timbers. Every drop of the 3phases were in arrays of 4 cables with square seperators keeping the 4 wires from tangling. Arent these lines actually supposed to be at a hieght greater than that of standard secondary transmission lines? I just worry that some unsuspecting farmer will snag this some day when he is shooting across the field with his cultivator extensions raised.
Hey Bennie, 10,000' I hope it payed good.
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
Peaveyone: The line is 230 KV or more. Conductor bundling is done to to reduce the energy field, decrease resistance, and reduce the inductive reactance. The conductors are shorted together at each spacer.
Line sagging is an engineered design, for tension and weight of the span. The integrity of the entire string depends on accurate sagging.
A farmer will not make a habit of hitting the lines.
Peaveyone: The line is 230 KV or more. Conductor bundling is done to to reduce the energy field, decrease resistance, and reduce the inductive reactance. The conductors are shorted together at each spacer.
Line sagging is an engineered design, for tension and weight of the span. The integrity of the entire string depends on accurate sagging.
A farmer will not make a habit of hitting the lines.
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
In 1963 I was working with a lineman, during the flood on the Klamath River. We were driving around trying to clear downed lines so power on others could be restored.
We found one line, on a farmers field, neatly rolled up, and the farmer was plowing. He said he rolled it up to avoid hitting it.
We had attempted to operate the reclosers many times attempting to burn faults clear. The farmer was lucky, and I was scared as hell.
In 1963 I was working with a lineman, during the flood on the Klamath River. We were driving around trying to clear downed lines so power on others could be restored.
We found one line, on a farmers field, neatly rolled up, and the farmer was plowing. He said he rolled it up to avoid hitting it.
We had attempted to operate the reclosers many times attempting to burn faults clear. The farmer was lucky, and I was scared as hell.
charlie
Senior Member
- Location
- Indianapolis
Re: ELECTRICAL WIRES HEIGHT REQUIREMENTS
The NESC is a performance code, in other words, the end result is the performance of the system. If a table requires 15 feet of clearance, then that 15 feet is under the worst of conditions. Here it is normally with 1/2 inch of ice at 32 degrees Fahrenheit and no wind. In other locations it may be heavy loaded wire on a hot day and no wind. With the short spans that electrical contractors use, 16 feet will do nicely under a prescriptive Code. The bottom line is about the same.
As far as enforcement of the NESC is concerned, it depends on the state and local areas as to who, if anybody, enforces the NESC. Generally speaking, it is the courts that enforce the NESC. In other words, someone has to be hurt (or killed) or something has to be damaged (or destroyed) and the case taken to court. If the electric utility has to pay too much in damages, they will start to comply with the NESC.
Speaking of service drops and service laterals, the requirements are in the NEC because there are situations where the customer is required to install the service drop or service lateral. Take the instance where the meter is installed at the property line without a disconnecting means. The customer would then be required to run the service conductors overhead or underground to his building. Remember, the meter is just the cash register, not service equipment.
The NESC is a performance code, in other words, the end result is the performance of the system. If a table requires 15 feet of clearance, then that 15 feet is under the worst of conditions. Here it is normally with 1/2 inch of ice at 32 degrees Fahrenheit and no wind. In other locations it may be heavy loaded wire on a hot day and no wind. With the short spans that electrical contractors use, 16 feet will do nicely under a prescriptive Code. The bottom line is about the same.
As far as enforcement of the NESC is concerned, it depends on the state and local areas as to who, if anybody, enforces the NESC. Generally speaking, it is the courts that enforce the NESC. In other words, someone has to be hurt (or killed) or something has to be damaged (or destroyed) and the case taken to court. If the electric utility has to pay too much in damages, they will start to comply with the NESC.
Speaking of service drops and service laterals, the requirements are in the NEC because there are situations where the customer is required to install the service drop or service lateral. Take the instance where the meter is installed at the property line without a disconnecting means. The customer would then be required to run the service conductors overhead or underground to his building. Remember, the meter is just the cash register, not service equipment.
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