There is an old barn on my farm that needs serious repair and one of
those projects that I am always planning to get to, but never do.
Anyhow, I went out to the pasture today and was rather shocked when I
found the overhead triplex to that barn was nearly touching the
ground. On closer inspection, I found that of the 3 wires, only one
of the hot wires was still attached to the barn, and was hanging by
the service entrance head that was pulled off the building. The
neutral cable, and other hot wire was just dangling in a tree.
I shut off the main disconnect and had to do some tree trimming to
finally get to the wire. What I found was a spot where both the
neutral wire and the hot wire were melted at that spot, which is about
10 feet from the old barn. The 3rd wire, (still attached one), had a
little burn on the insulation, although not down to the bare wire.
Because there is no way to shut off the power to this one wire, I just
temporarily capped the end of the hot wire and propped a 12 foot 2x6
under the center of it, to keep some of the weight off and keep if off
the ground. Tomorrow I will (somehow) reattach it, or just remove it,
since it's not really needed.
Anyhow, I am puzzled how, or why it burned at that spot?????
It's been there for years. Although it's not used, it's been live,
and did not have a tree or anything else fall on it, nor did we have
any wind storms lately. Why would it burn thru, and not blow the main
breaker? This has me puzzled. Even if there was a little nick in the
insulation on the hot wire, why would it contact the neutral for no
apparent reason? I should note that the break occurred in the
branches of that tree. I do not see any burn spots of the tree, even
after I did some serious trimming on it. Is it possible that the tree
got wet (we just had a lot of rain), and the tree served as a short?
That's all I can figure. I should note also, that the wire is not
rubbed bare, like a tree branch was rubbing, it just burned cleanly in
half, both the neutral and that one hot wire. I just find this real