OK, I've watched this thread long enuf.
1st my qualifications: 21yrs. with the Board of Public Utilities in Kansas
City, Kansas.
One rule to remember: ALL LINES CAN BE DEADLY!!!
Now, lets assume the triplex (or concentric neutral line, or open wire
service, whichever it maybe be), is fed from a 37.5 KVA transformer. A
single 120 leg of the feed is capable of 312.5 AMPS and NOT exceed the
capabilities of the xfrmr. That is NORMAL FULL LOAD. Not a short or low
impedance route to ground or thru you. Then it is ALMOST unlimited in
amperage. This is totally dependent to length of time of the short. Now as
for the durability of the insulation on triplex or any other wire, let me
related this story. A few years ago, we had a wind storm roll thru KCK. As
we were clearing lines and repairing them to restore power, we ran across a
tree limb that fell across the service drop, which WAS 4/0 triplex, and
VISUALLY in good shape. This limb pulled the triplex onto a 3/4 catv feeder
line for the neighborhood. Looking at the situation, if we got the limb off,
that would clear up the problem, and we could go on. Taking our fiberglass
hot stick, we moved the branch just an inch, and POOF, there was a bare spot
(just 1/4 inch in diameter) on the triplex, which burned the triplex AND the
CATV line in 2. Now assuming that it looked good, would I drop a BARE wire
across this?? Not in this lifetime. Think about gentlemen, would you want to
take that chance?? Also the current rating for the 120 leg was taken from
Howard Industries "Distribution Transformer Connections" Booklet. I have
worked with busses from 120 all the way to 161KV in the last 21 yrs. Thing
happen TOO fast to take chances. BURY THE DROP!!!
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