sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Cat 6 cable didn't pass certification

3- Cat 6 plenum runs 200 ' through EMT, then another 150' through a cable tray. Were getting interference, so cables won't pass certification. Part of EMT has 2 fire alarm cables in them, cable tray has many cables in them. If interference is from cable tray, wouldn't other existing cables get interference on them also? Trying to figure out where this is coming from.

Are they only failing due to noise? They should also fail on distance at 350 feet. Of course the longer the cable run the more noise you will have.

What exactly do you mean by interference? Does the cable tester detect AC noise? Is it failing NEXT, FEXT, PowerSum? What type of cable tester are you using and what does it actually say?

Do you know for a fact that the other cables don't have any noise issues? Have they been certified? If so, were they certified at Cat5e or Cat6? It's entirely possible the other cables do have noise if there is AC running in the same tray. Maybe nobody has noticed how poorly the network performs.

You might be right about the other cables and poor network performance, don't know.

The certifier says hes passed cables that were in the 350' range before. Different readings at different times, crosstalk, shorts, opens. At one time, I tested all 3 cables with a continuity tester, prs. 1-2 and 7-8 were open on all 3 cables. 2 hrs. later, all prs. were good for continuity.

In the morning certifier failed cables. After 5 PM, miraculously, they all passed. The certifier equipment is some kind of "Platinum" equipment.

Well if you have a cable tester that will pass a cable run longer than 328 feet, it can't be a proper certification tester. One of the first tests is typically for length. If the cable is 350 feet, it fails the first test and there's no point doing anything else. Technically you should only get a marginal pass if it's over 300 feet, as you still have to account for patch cables at either end. Perhaps your company has a qualification meter instead of a certification meter.

As for the continuity changing...that wouldn't have anything to do with outside noise. If this happened to me I would assume I made a mistake in the testing the first time. If you're certain it happened like you describe, then the cable must have been damaged or the terminations are faulty.

What is the far end terminated with when you are testing? Network card is going to screw up results, esp if the computer/whatever is 'on'. If you are using some sort of fixed terminating device, try another, sounds like on top of everything else, your 'known termination' isn't.

Did you use cable lube? It could fail the cables in conduit until it dries in a day or two.

I Ran a cat 6 in a condiut and it failed. I pulled it out and put in a new one and it failed too. I scanned the one I pulled out and it passed out of the conduit. I called Fluke and they said cable lube will cause failures until the lube dries.

Why are you trying to certify a cable run that is 350'? Its going to fail because of the distance alone!I second what Clinton says. If a scope passes a 350' cable run then the margins have been played with and its not up to standards regardless of what the tester says.

The Cable lube caused Attenuation and NEXT failures in my case.

Oh no not the wrong color code! These deviant cretans should be droned out of existence. Seriously though, I am working on a job right now that is an absolute rat's nest. Don't you love it too, when a pair starts out one color, becomes another color and ends up a third color? It makes life interesting.

If you were getting "opens", I'd fix that before I even bothered with looking at noise. Sounds like the cables aren't mechanically terminated properly. I don't think the opens would be due to lube.

If nothing was done to the cables between when you saw "opens" and when your continuity tester started passing the cables, I'd refuse to accept the cable run job as complete until I had someone else take a look at it. If nothing was done, those terminations will fail again later, by themselves, without help - just like they "fixed" themselves.

Your continuity tester could also be broke - I'd try it with some decent commercial patch cables and see if you can induce it to fail. I would also make sure to have no non-commercial patch cables in use on the run during testing...(none at all would be better). Make sure that the patch cord isn't a a two-pair phone cord, either (which would give you an open on 1/2 and 7/8.

I agree with everyone else on lengths too.

Also, if the certification tester he is using can't generate a nice printed report on your cables, it's likely not a certification tester (not every tester that generates printed reports is a certification tester, but almost all certification testers I've seen do this - after all, the customers would usually want proof of the certification, right?).