One of the buildings I support recently had an adventure with a broken fire sprinkler. Lots of water everywhere.
One of the "drains" the water used was the vertical risers between network closets. The cable plant in this building has bundles of cat5e as well as conduit with bundles of multimode fiber optic cables. The fiber is standard multi strand plenum rated stuff that terminates in boxes that have the patches to the switches.
As far as I can tell, no water got near the ends of the cables (fiber or copper) but the conduit was saturated, and is likely still saturated because there isn't any air flow to dry the cables out.
My gut reaction is that while it didn't do the cables any favors, it likely also isn't going to cause any problems. A little more reading / googling around leads me to believe that the water may cause problems down the road.
Some pretty pictures so everyone knows what I'm talking about:
Fiber conduit:
Vertical riser, going down:
Vertical riser, going up:
Does anyone have any experience with this sort of damage and how to deal with it? Should we just ask the insurance adjuster to add "pull new structured cable" to the list of things to be replaced?
And, if the opinion is "replace it because it'll start failing randomly over time" please include links that describe the specific failure modes, so I've got some ammo to use with the adjuster.
Best Answer
The real danger is at the terminations, where corrosion can start. As for the cables themselves, they're fine in water, although I'd be careful using it in a corrosive solution. Keep an eye open and you should see plenty of examples of network cables, including fibre, used outdoors in the weather. I know of examples where cables sit permanently in water and have done so for many years. Network cabling is no different to any other kind of electric cabling. Keep the ends dry and the rest doesn't matter.