Underground fiber cable?

[Mike K]

I thought this was going to be the easy part but maybe NOT.

I need a single multi mode LC to LC duplex fiber cable about 80' long, probably an OM3,or OM4. Approximately 30' goes underground.

So naturally I start looking for an underground cable for the entire length. However, to my surprise I find only duplex cables with "outdoor" ratings. Not underground ratings. Am I missing something?

 

[nayr]

'underground' fiber is going to be direct burial, without conduit.. so it'll be armored.

outdoor rated fiber should be fine for use within buried conduit.

 

[Mike K]

'underground' fiber is going to be direct burial, without conduit.. so it'll be armored.

outdoor rated fiber should be fine for use within buried conduit.

Thanks Nayr.

I'm still wondering why I can not find an underground Duplex cable? I don't see any reason that an underground cable couldn't be pulled through an underground conduit, even though it might be an overkill. Many hear seem to feel that conduit will eventually leak and fill with ground water.

 

[nayr]

as long as it dont freeze fiber can run fully submerged without any issues.. its not going to corrode or anything.

if you dont get it below frost line, a conduit full of water with a fiber in it could get cut/crushed by the ice expanding.

underground cable has to be grounded and wont electrically isolate your buildings because of its armoring.