Wiring to a tree-mounted flood light

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tonype

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I've read previous threads on wiring to trees - I'm still fuzzy on this.

I saw a home with UV wiring (120-volt) up a tree to a flood light - the tree was starting to grow around the wire. Wire was fed to the tree with conduit up to about 3' from grade, then went to UV stapled to the trunk.

Comments?

Regards,
Tony Shupenko
 
Johnmcca said:
As I recall you can have the wiring in the tree or vegetation for lighting, you just can't string the wire from tree to tree.
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Is there any concern with the tree starting to grow around the wire to a point where it will not longer be visible?
 
If you have a Handbook the explanator print to 225.26 will provide the answer maybe someone has it disk and can cut and paste

Charlie
 
cpal said:
If you have a Handbook the explanator print to 225.26 will provide the answer maybe someone has it disk and can cut and paste

Charlie
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225.26 Vegetation as Support
Vegetation such as trees shall not be used for support of overhead conductor spans.


Where overhead conductor spans are attached to a tree, normal tree growth around the attachment device causes the mounting insulators to break and the conductor insulation to be degraded. The requirement in 225.26 reduces the likelihood of chafing of the conductor insulation and the danger of shock to tree trimmers and tree climbers. The exception to 225.26 permitting trees as a support method for overhead conductor spans on a temporary basis was deleted in the 2002 Code. However, outdoor luminaires and associated equipment are permitted by 410.16(H) to be supported by trees. To prevent the chafing damage, conductors are run up the tree from an underground wiring method. See 300.5(D) for requirements on the protection of direct-buried conductors emerging from below grade.
 
I am still not clear on this - can I conclude that tree growth around the wire is not a concern (other than for overhead spans)? Or is it just not addressed anywhere?

Regards,
Tony
 
As Mike posted

"To prevent the chafing damage, conductors are run up the tree from an underground wiring method. See 300.5(D) for requirements on the protection of direct-buried conductors emerging from below grade.
__________________
Mike Whitt "

This last sentence would indicate that the Tech Rep who composed the explanatroy print in the HB realizes if a lamp holder (fixture or luminair) is allowed to be supported from vegetation (trees in this case) then the wiring method has to get there by some route other than overhead (unless temp wiring).

That being said i would guess underground (in most cases). IMO I would have a problem with UF Cable (article 340) in light of the language of 340.12 (10). physical damage.

Usually I see these installations in PVC (sch 80??)


Charlie
 
300.5
D) Protection from Damage. Direct-buried conductors and cables shall be protected from damage in accordance with 300.5(D)(1) through (D)(4).
(1) Emerging from Grade. Direct-buried conductors and enclosures emerging from grade shall be protected by enclosures or raceways extending from the minimum cover distance below grade required by 300.5(A) to a point at least 2.5 m (8 ft) above finished grade. In no case shall the protection be required to exceed 450 mm (18 in.) below finished grade.
(2) Conductors Entering Buildings. Conductors entering a building shall be protected to the point of entrance.
(3) Service Conductors. Underground service conductors that are not encased in concrete and that are buried 450 mm (18 in.) or more below grade shall have their location identified by a warning ribbon that is placed in the trench at least 300 mm (12 in.) above the underground installation.
(4) Enclosure or Raceway Damage. Where the enclosure or raceway is subject to physical damage, the conductors shall be installed in rigid metal conduit, intermediate metal conduit, Schedule 80 rigid nonmetallic conduit, or equivalent.
 
I'm more concerned with the tree growing and stretching the wire (pulling it in two) than I am with it growing around it.
All of Article 410 and more specifically 410.16(H) [which refers you to 225.26 and 300.5(D)] is all there is (2005 NEC).
You can't use a tree to support a overhead span to feed a light fixture. I (IMO) believe that means a underground feed must be used. The wire must be enclosed in conduit that extends from a minimum of 18" below grade to at least 8' above grade or to the fixture, which ever is closest , so there is really no hazard to people if the wire breaks or is covered by the tree bark.
steve
 
hillbilly said:
I'm more concerned with the tree growing and stretching the wire (pulling it in two) than I am with it growing around it.
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Don't think that is a problem; the existing tree will grow in diameter, but a basketball goal bolted to a tree will be within an inch of where it was 20 years later ... but the bolts (and likley part of the goal) will be inside the wood.

This was a Loblolly pine, in case it matters, and put in in 1964. One bolt broke in 1995 or thereabouts, stretched by the goal mounting plate, and a little rusty.

If the lamps were mine, and the electrician I hired to put some in a tree did it that way (I do industrial automation and control, not "wiring"), it would be S80 PVC then NM flex to the luminaire.
 
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