On 7/30/2020 9:28 AM, dpb wrote:
On 7/30/2020 8:55 AM, wrote:
....

Custom Bends: about 8Â* (and that's before I start digging !)

You'll never get it pulled, then, unless you can run sections at a time.
Â*Remember the Code 360 rule. That applies to the power run.

While it's not Code, it is very common for industrial specs (like phone
and optical) to enforce a 180 rule as even more restrictive given the
less forgiving nature of the conductors and that the cable is as
somebody else already pointed out, harder to pull.

GEEZER STORY ALERT/

We had to pull coax for the coal analyzer detector head -- a NaI(Tl)
scintillation counter. In the days before vendors developed integral
electronics it required both a HV (1200 VDC) bias supply and a second
signal cable for the preamp input to the multichannel analyzer. We
would have customer pull at least two pair if not three for at least one
spare.

At one site, the analyzer on the coal belt had to be across large drive
area back to the office where the monitor equipment rack was located.
It was roughly 100 yds across and had to be buried deep enough large
equipment typical of mine wouldn't crush. They ran 3" plastic conduit
for the pull.

But, they weren't able to pull it by hand -- being miners, they did the
obvious--tied it to the nearest frontend loader and had no problem at
all in pulling it.

We weren't on site for the prep work; when went for final install of the
sources and startup/calibration, all seemed fine. Left it operational
and went home (mine in middle E-KY, office in E TN about 3 hours drive
thru the mountains). Lasted until first rain and lost HV. Had them try
the spare -- it worked and were back on line. That lasted about a week
until next rainy spell. They had only pulled two, so that was the end
of it until figure out what happened.

Service call proved was dead short on both HV cables and one of the
signal cables and the second signal cable was degraded.

They were unable to pull the existing cables back out; dug up the near
end to the shack down to the elbow (about 3 ft). They had pulled so
hard/fast with the endloader had melted thru the conduit and welded the
cable in place...had to re-run the whole installation...this time made
sure they did it so the cable could be pulled...

The new cables lasted the 7-8 more years I was still in TN...it's now
been another 20 almost since...now idea if the mine is still
operational, even.

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