[TowerTalk] [Bulk] Re: Water in Conduit...

[Grant Saviers]

A little moisture in conduit isn't always a bad thing.  We pulled 3 x 
LDF5 with a powered capstan from 100+ plus of 3" conduit that sloped 10 
ft downward from shack to pull point.  Any pooled water would have 
drained out.  Condensation kept the pulling lube slippery after 7 years 
and they were retrieved in perfect condition.  Two LDF4's came out of 
another 70' of 3" conduit and that was pulled by hand.  A slip noose 
made from a technical climbing sling, grips nicely and is quickly 
repositioned without damage (check REI catalog).  Also great slings to 
have an assortment of when doing tower work.  18mm nylon is my choice in 
several lengths and colors.

Another problem with holes in the conduit (ie using drain pipe) is dirt 
and sand will wash in, making removing what is there much more 
difficult.  All of my installations are pvc glued, to make them pressure 
water system tight.  No problems about 1000 feet in the ground, over 
several QTHs.

Grant KZ1W


n 3/5/2015 5:44 PM, Roger (K8RI) on TT wrote:
> I agree with Jim and I'll add this again with a bit more detail:
>
> I use 3" PVC conduit with NO drain holes and NO glue.  Sll joints are 
> greased with either DC4 or DC5 compound (Silicone Grease) with the 
> pipe installed with linear compression.  During much of the year, the 
> basement is much warmer than outside, providing substantial convection 
> air flow.  The flow first enters a steel NEMA box on the outside 
> wall.  The Conduit leaving the box extends "up into the box about an 
> inch." Most condensation takes place in that box.  Any liquid in the 
> box is trapped.
>
> In the warmer months the flow is reversed with the temperature in the 
> conduit and basement being much cooler than the outside temp. In 
> spring and fall which are often quite humid there can be substantial 
> air flow with the associated condensation.  The air flow can easily be 
> enough to blow out a lit match.   However, the flow often reverses 
> between day and night with the nightly outflow "usually" drying out 
> the day's accumulation.
>
> OTOH, as Jim said, even if the conduit is full of water there are 
> those infamous words, "what difference does it make?"  IOW, The big 
> boys (commercial ops) pull through conduit full of water with little 
> or no problem.
>
> Pulling "LUBRICATED cable in or out of conduit makes a huge 
> difference!"  Look at the last photo on 
> http://www.rogerhalstead.com/ham_files/cablebox.htm  to see a liberal 
> application of wire pulling soap.  It make pulling the "BUNDLE" in 
> much easier and pulling only a single cable out much, much easier as 
> the cables do not grip others in the bundle.  It's like working with a 
> bundle of cables covered with snot!
>
> BTW that page also shows much of the evolution my feed system has gone 
> through.
>
> Get some help. One guy pulling with two lubing ( one holding and 
> spreading the bundle while applying  the wire pulling soap. The second 
> squirting the soap into the first's hands) and another feeding the 
> cables into the "soaper's" hands.  With little practice the cable 
> pulling operation is quick and easy.  So is pulling a wire or two 
> out.  Do this with all wire bundles going through conduit, even AC 
> wires through EMT indoors.
>
> 73
>
> Roger (K8RI)
>
>
> On 3/5/2015 5:52 AM, Jim Thomson wrote:
>> Date: Wed, 4 Mar 2015 21:34:54 -0600
>> From: "Perry K4PWO" <k4pwo at comcast.net>
>> To: <towertalk at contesting.com>
>> Subject: [TowerTalk] Water in Conduit...
>>
>> I still don't understand the "French drain" stuff.  I have a 70' run 
>> of two
>> 3", one 2.5", and two 11/4" conduits from my tower to my house. At 
>> each end,
>> I have the conduit terminated in metal 18" X 16" X6" NEMA 4 boxes.  The
>> boxes allow the conduit to breath and in the seven years they have been
>> installed, all I've found in them is cob webs.  I just pulled some 
>> Cat 5E in
>> one of the 11/4" runs and it was as dry as a bone.
>> Like a lot of the Southeast we are currently in the middle of a freezing
>> lake... flood, then ice, finishing with snow. In other words a lot of
>> moisture.  If I had used the "French drain" my coax coax would be 
>> swimming.
>>
>> Perry K4PWO
>>
>> ##  The problem with using that pvc pipe that has the rows  of holes 
>> on each side is..
>> its meant for perimeter drains.... to allow water INTO the pipe.   
>> For ham use, the
>> pipe would have to be flipped 90 degs..so the holes are at 12 and 6 
>> oclock...to allow
>> water out the bottom holes..into some gravel bed etc.  Trbl is.... it 
>> will also allow water
>> in through the top holes!   You would be better off to buy pipe with 
>> no holes..then drill
>> ur own holes..at  6 oclock only.
>>
>> ##  On a similar note, the telcos, power and cable companies all use 
>> pvc pipe..
>> with no holes at all.    Each end of the pipe is terminated 
>> correctly, and the entire
>> length can breathe.   Never saw one with water issues in it. Telcos 
>> used to direct bury
>> a lot of stuff..in residential areas.  That stopped a long time ago.  
>> Cable goes bad,
>> and has to be replaced.    That requires ripping up every driveway 
>> and boulevard
>> up and down the street.   When the replacement cables started to go 
>> bad, and a 3rd
>> was required,  city hall read em the riot act..... no more direct 
>> bury.  Everything
>> has to go into pvc pipe..and big diam stuff too.
>>
>> ##  a lot of problems with ham installs is..too small a diam pipe is 
>> used....and down the
>> road this  will bite you.  Flip side is.... trying to remove a cable, 
>> when several are already
>> inside the same pipe is a real pita at times, with cable sheaths 
>> burning on each other.
>> Cables should be  lubed  before install.  How long the lube will last 
>> is anybodys guess.
>>
>> ##  Plan B would be to install several pipes at the same time... at 
>> least two.   With coax
>> in one..and control, misc and any power cables in a 2nd pipe. Use 
>> control cables with plenty
>> of spare conductors.   You might even want to run spare coax cableS  
>> as well..at the same
>> time, then cap off the spares at each end.   Its actually easier to 
>> run all the intended cables
>> at one shot..all at the same time.. vs 1 cable at a time.
>>
>>
>> ##  if running cables laid on top of the ground, that split loom, 
>> corrugated  tubing,
>> installed over top of the cables will allow for a certain amount of 
>> protection.
>>
>>
>>
>> Jim   VE7RF
>>
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