What is the correct way to feed 1 - 120V overhead circuit to a shed that is 60' away from a house? I have seen installations were someone used a screw in insulator on each corner of the house and shed, and then strung a piece of 12/2 UF cable from bldg. to bldg., but that doesn't look like an NEC acceptable installation to me. Maybe I'm wrong.
Overhead circuit
- Thread starter ih8shorts
- Start date
- Status
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Overhead circuit
There must be a messenger wire to hold the weight of the wire 255.6. and you have to maintain 10' above grade even where the wire runs into the building 255.18.
Where the cable enters the building it must follow 230.52 and 230.54 as per 255.11
Point of attachment is in 230.26 and means of attachment is in 230.27 as per 255.16, 255.17 respectfully.
There must be a messenger wire to hold the weight of the wire 255.6. and you have to maintain 10' above grade even where the wire runs into the building 255.18.
Where the cable enters the building it must follow 230.52 and 230.54 as per 255.11
Point of attachment is in 230.26 and means of attachment is in 230.27 as per 255.16, 255.17 respectfully.
charlie
Senior Member
- Location
- Indianapolis
Re: Overhead circuit
Messenger wire is any wire that is strong enough to handle the load. In the case of triplexed conductor, the neutral is the messenger. Many times, I have seen guy wire used as a messenger. I don't know of any wire or cable that is sold just for that purpose. In this case, a piece of clothes line wire may be sufficient. You have to be sure that the wire will handle the load. If it were being installed here, the load would be approximately the diameter of the bundle (?"?), plus ?" of radial ice (we are in a heavy loading district), and 4 Lbs. per square foot of surface area of wind. I am guessing about 600 Lbs is what you will end up needing to carry in the worst winter weather (that is putting it up by hand and not pulling it in like a banjo string).
I am getting those numbers from the NESC but the tensions will be the same.
Messenger wire is any wire that is strong enough to handle the load. In the case of triplexed conductor, the neutral is the messenger. Many times, I have seen guy wire used as a messenger. I don't know of any wire or cable that is sold just for that purpose. In this case, a piece of clothes line wire may be sufficient. You have to be sure that the wire will handle the load. If it were being installed here, the load would be approximately the diameter of the bundle (?"?), plus ?" of radial ice (we are in a heavy loading district), and 4 Lbs. per square foot of surface area of wind. I am guessing about 600 Lbs is what you will end up needing to carry in the worst winter weather (that is putting it up by hand and not pulling it in like a banjo string).
I am getting those numbers from the NESC but the tensions will be the same.
macmikeman
Senior Member
- Location
- Planet macmikeman
Re: Overhead circuit
Not to change the thread direction, but I have witnessed an arial run of 12-uf that had become completely cracked and bare in parts due to from the way it looked was long term sun damage and drying out of the uf sheath. It looked older than twenty years,so I think for a shorter term solution this may not be so bad, but if meant to be permanent maybe you should consider underground
Not to change the thread direction, but I have witnessed an arial run of 12-uf that had become completely cracked and bare in parts due to from the way it looked was long term sun damage and drying out of the uf sheath. It looked older than twenty years,so I think for a shorter term solution this may not be so bad, but if meant to be permanent maybe you should consider underground
charlie
Senior Member
- Location
- Indianapolis
Re: Overhead circuit
That is why UF cable is required to be sunlight resistant if run exposed.
That is why UF cable is required to be sunlight resistant if run exposed.
bphgravity
Senior Member
- Location
- Florida
Re: Overhead circuit
Perhaps this is another reason why additional derating should be applied to conductors or cables exposed to direct sunlight such as proposed for the 2005 NEC, 6-45. The proposal suggests that 30 degrees F should be added to the ambient temperatures when calculating conductor ampacities per Table 310.16. This would be consistent with UL listing requirements for RNC expansion fittings in direct sunlight.
Perhaps this is another reason why additional derating should be applied to conductors or cables exposed to direct sunlight such as proposed for the 2005 NEC, 6-45. The proposal suggests that 30 degrees F should be added to the ambient temperatures when calculating conductor ampacities per Table 310.16. This would be consistent with UL listing requirements for RNC expansion fittings in direct sunlight.
charlie
Senior Member
- Location
- Indianapolis
Re: Overhead circuit
Bryan, is 30?C enough in Miami or way too much in Anchorage? The NESC has districts or zones for loading of conductors for wind and ice. Shouldn't zones be set up for this? The testing was all done in Nevada I believe, that is not representative of Indiana.
Bryan, is 30?C enough in Miami or way too much in Anchorage? The NESC has districts or zones for loading of conductors for wind and ice. Shouldn't zones be set up for this? The testing was all done in Nevada I believe, that is not representative of Indiana.
bphgravity
Senior Member
- Location
- Florida
Re: Overhead circuit
I agree Charlie. I just think the study was interesting and may have some merit.
Here in Florida, we have building construction zones for hurricanes. Coastal areas are in the higher wind zone and require additional structural requirements compared to buildings or structures built more inland.
Perhaps the requirement shouldn't be added as worded in the proposal but direct exposure to sunlight should probably have some consideration.
I agree Charlie. I just think the study was interesting and may have some merit.
Here in Florida, we have building construction zones for hurricanes. Coastal areas are in the higher wind zone and require additional structural requirements compared to buildings or structures built more inland.
Perhaps the requirement shouldn't be added as worded in the proposal but direct exposure to sunlight should probably have some consideration.
charlie
Senior Member
- Location
- Indianapolis
Re: Overhead circuit
While I agree, EEI and others fought the proposal based on the single test site. Bring tests to the panel from scattered sites and it will pass. I believe a task force was appointed to study the issue for the 2008 Code.
While I agree, EEI and others fought the proposal based on the single test site. Bring tests to the panel from scattered sites and it will pass. I believe a task force was appointed to study the issue for the 2008 Code.
- Status