[TowerTalk] Water in buried conduit

[Dick Green WC1M]

I guess it's possible. My conduit runs are terminated in weather-sealed Hoffmann metal boxes at both ends. The box at the shack end is mounted to the house and has holes drilled in the back just above the sill to run the cables to a patch panel in the basement. So the conduits are exposed to the air inside my house. At the tower end, cables run to the antennas through holes drilled in the bottom of the utility box. In some case I used coax feed-through bushings and in other cases I ran cables through fittings with rubber gaskets that tighten against the cable. I tried to plug any visible holes with coax seal. I don't get insects in the box, but I imagine it's not perfectly sealed against air coming in through the cable exit holes.

So the long and the short of it (no pun intended) is that air probably can circulate through the conduit, though I'd say it would be a very restricted flow at the tower end. Our ambient humidity here in West Central NH tends to run 40%-100% most of the time, so there's almost always enough water in the air to condense. 

Any water condensing in my conduits would cling to the insides, but I would think eventually it could drip to the bottom and run downhill to pool at the low point of the 90-degree bend, which is where I know the water is. Could enough water condense in my conduits over a period of 16 years to soak a few dozen feet of cable? I don't know. I'm certainly not worried about it.

73, Dick WC1M

> -----Original Message-----
> From: jcjacobsen at q.com [mailto:jcjacobsen at q.com]
> Sent: Tuesday, February 26, 2013 10:45 AM
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Water in buried conduit
> 
> How do,
> 
> Regarding water in buried conduit: Is it possible that the water is
> actually condensation that has built up over time?? It would seem to me
> that if the joints were well glued/connected there should be no water.
> Years ago I watched as some electricians placed some buried
> galvanized/rigid/threaded conduit between buildings at a commercial
> site. After the sections were threaded together they wrapped each joint
> with some 2" wide tape. Don't know if it was 33/88 type or some kind of
> rubberized tape. I guess a belt and suspenders approach. YMMV.
> 
> 73
> K9WN