My answer would be that the code does not permit this type of installation in residential. I went to Article 340 on UF cable and read that it's not permitted per 340.10(11) that sends you to Article 396. In 396.10(B) the first words are "In industrial establishments only, ......."
225.18 Clearance from Ground. Overhead spans of open conductors and open multiconductor cables of not over 600 volts, nominal, shall have a clearance of not less than the following: (1) 3.0 m (10 ft) — above finished grade, sidewalks, or from any platform or projection from which they might be reached where the voltage does not exceed 150 volts to ground and accessible to pedestrians only (2) 3.7 m (12 ft) — over residential property and driveways, and those commercial areas not subject to truck traffic where the voltage does not exceed 300 volts to ground (3) 4.5 m (15 ft) — for those areas listed in the 3.7-m (12-ft) classification where the voltage exceeds 300 volts to ground (4) 5.5 m (18 ft) — over public streets, alleys, roads, parking areas subject to truck traffic, driveways on other than residential property, and other land traversed by vehicles, such as cultivated, grazing, forest, and orchard
340.10 says that you must comply with part II of Article 396. George, I think you are only quoting one of the rules found in part II, which is for individual conductors.
Type SE and UF cables are not the same, as listed in the code. RE: Article 340.12 Uses not permitted. 9) Where exposed to direct rays of the sun, unless identified as lunlight resistant, and, 11) As overhead cable, except where installed as messenger-supported wiring in accordance with Part II of Article 396. I do not believe 396 excludes this installation for residential, but you might double check. It DOES have section B that specifically addresses Industrial, but is not inclusive of this section in its requirements, only the type of support systems. Also, refer to 225.6, which list minimum sizes for these installations, which would be #8 cu, #6 AL, for over 15'. BUT, the cable must be sunlight resistant.
Whooops, sorry. 225.6 is for individual conductors. Guess it's just a support system, clearance to ground, and sunlight resistant cable, as far as I can see. Hey, what about triplex; it has a built in messanger cable.
Your correct Ryan, I only referenced part of the Article but, read the definition of Messinger Supported Wiring and when I read it I don't see using UF 12/2 for this type of application with out a support system.
After reading Article 396 more closely, I guess it would be permitted to install UF cable in a "Messenger Supported Wiring system, as discribed in 396.2. It also appears that it would be more practical to install triplex.
[This message has been edited by George Little (edited 06-06-2005).]
I just assumed it was OK to run UF as an overhead span because I've seen it so many times around here in New England to feed sheds or accessory buildings.
With a porcelin screw-in anchor on each end of the span, proper drip loops, and enough ground clearance, what danger could UF wire present compared to single conductor or a triplex overhead span installation?
Was UF ever allowed as an open non-mesenger supported overhead span?