Overhead feed to outbuilding

[Bruce Ramsey]

The property had an outbuilding approximately 8 feet away from the house. They stapled a cable under the soffit of the house up near the ridge, and then draped the cable over to the outbuilding, stapled it to the outbuilding, ran it through a metal pipe down to within 6 inches of the ground. The cable exited the pipe went back up 6 inches into a junction box. The cable left the juntion box to travel under the outbuilding to a point where they drilled a hole in the floor and stuck it up into the outbuilding.

The cable draped between the house and the outbuilding was only 8 feet above the ground at the lowest point. Partly because one or more staples had pulled out allowing the draped cable to hang lower. Of course there is a mature tree between the house and outbuilding with lots of branches to break and fall on to the draped cable.

There are min height rules for service cables but are there any height rules for feeder cables to outbuildings?

Seems like we discussed this recently and the pictures of that particular discussion showed a cable over porch/deck stairs and landing. Might have been snow in the pic. Could not find the topic.

[Jerry Peck]

Bruce,

WAY to many things wrong with that installation to try to start to identify them all, so let's suffice it to say:
- minimum height above finished grade, walkways, patios, decks, etc., accessible to pedestrians ONLY would be 10 feet
- minimum height over residential property accessible to other than pedestrians ONLY would be 12 feet ... I suspect this does not apply to your area shown in the photo

Have the electrician correct the above and ... and correct any and all other non-code complying conditions found or created during the repair.

[Bruce Ramsey]

Thanks, I was planning to use the service cable requirements as a starting point.

This was just a small sample of the creative wiring of the house.

[Jerry Peck]

Thanks, I was planning to use the service cable requirements as a starting point.

This was just a small sample of the creative wiring of the house.


Actually, those are not from the service drop requirements and you would not want to refer to it as such.

From the 2008 NEC.
- ARTICLE 225 Outside Branch Circuits and Feeders
- - 225.18 Clearance for Overhead Conductors and Cables.
- - - 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

Those are for outside overhead branch circuits and feeders, so that is how you should address it.

[Jerry McCarthy]

Helpful diagram

[Jerry Peck]

WC Jerry,

While that drawing does show the same clearance, it is referencing the "service drop" conductors.

The ones Bruce asked about are either feeders or simply a branch circuit, thus E3504.2.2 would be an incorrect reference.

That said, there is no correlating reference in the IRC Electrical section similar to 225.18 in the NEC, which does not present a problem as that is addressed here:
- E3301.1 Applicability. The provisions of Chapters 33 through 42 shall establish the general scope of the electrical system and equipment requirements of this code. Chapters 33 through 42 cover those wiring methods and materials most commonly encountered in the construction of one- and two-family dwellings and structures regulated by this code. Other wiring methods, materials and subject matter covered in the NFPA 70 are also allowed by this code.

Thus, while overhead conductors other than service drop or service conductors are not specifically allowed by the IRC Electrical chapter, they are allowed by the NEC by reference in E3301.1 Applicability.