There are vast differences in soil across the count. One has to do his/her
research and follow the area practices accordingly. Steve N0SM
________________________________
From: Eugene Jensen <eugenejensen@nyc.rr.com>
To: 'Joseph or Ruth Patrick' <hdmc38@bellsouth.net>
Cc: TowerTalk@contesting.com
Sent: Saturday, May 25, 2013 3:02 PM
Subject: Re: [TowerTalk] Need Help For Cable Runs To Tower
Drilling holes in conduit for drainage is not a good ideal. It going to be full
of water in time. As long as your trench is 18 " or deeper you could use UF
#6-2 with ground to keep the voltage drop under 3%. And the run your
control/Rf cables in the same conduit, It you using hard line just bury it in
the trench. 73 and good luck with your tower project. Gene AA4VX
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Joseph
or Ruth Patrick
Sent: Saturday, May 25, 2013 1:08 PM
To: Jim Lux
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Need Help For Cable Runs To Tower
I agree with Jim. It is not code to put high voltage and low voltage in the
same conduit. That being said a lot of people do, but don't do it. I live in
Florida where the water table can be 18" down or more depending on location. We
do not drill holes in the bottom of underground conduit. Again Lot's of people
do. This is JMHO. I do not claim to be an expert. Good luck.
73 DE K4XZ Joe Patrick
God Made Man
Sam Colt Made Them Equal
________________________________
From: Jim Lux <jimlux@earthlink.net>
To: towertalk@contesting.com
Sent: Sat, May 25, 2013 11:47:44 AM
Subject: Re: [TowerTalk] Need Help For Cable Runs To Tower
On 5/25/13 8:36 AM, Wayne Willenberg wrote:
> While I am waiting for my 89’ crank-up tower to be built and
> delivered, I thought I would get busy running the various control
> lines for the rotator, the AC power for the motor that lifts the tower
> and, of course, the RF cable for my antenna that will be on top of the tower.
>
> I would like to place these lines underground from the panel entrance
> to my shack to the base of the tower. (That total distance is about
> 175 feet) My first thought was to run the cables through PVC pipe, and
> to use Andrew LDF5-50A Heliax (7/8”) for the RF cable. Of course, I
> will have to use a flexible coax from the base of the tower to the top of the
> tower.
>
> I would really appreciate some advice before I start trenching. For
> example,
>
> 1) It would seem logical not to put the RF cable in the same PVC pipe
> as the 220 VAC wire for the motor and the power and control lines for
> the rotator.
And combining power lines and "Class 2 power limited" low-voltage circuits in
the same conduit/enclosure/etch is specifically prohibited by most electrical
codes.
If it is better to separate the RF cable from the other lines,
> how far apart should the 2 PVC pipes be?
They can be next to each other. the concern isn't electrical, it's mechanical:
in order for there to be an inadvertent short from power circuit to "low power"
circuit, you'd have to have two barriers fail (i.e. conduit walls).
You can combine the coax and the low voltage control lines in one conduit:
they're all "power limited" circuits.
>
> 2) Should I drill holes in the bottom of the PVC to allow any water
> that gets into it to drain away?
That's a subject of much discussion and subject to local conditions, like
whether the animatronic owl needs to be periodically reoriented as the Earth's
spin axis changes.
I don't drill holes in mine, but I live in relatively dry Southern California,
and I make sure the stub up ends at least a foot above ground surface (so that
sprinklers, and such don't wind up putting water into the it). Mostly when I
pull the wires out, they're dry, but every once in a while they're damp. The
only time I had "wet" (as in the conduit was full of water) was when there was
a shovel and big rock induced break in the conduit that I didn't catch early on.
>
> Thanks as always for your help with my first tower.
>
> Wayne, KK6BT
> _______________________________________________
>
>
>
> _______________________________________________
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> http://lists.contesting.com/mailman/listinfo/towertalk
>
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