atcomsystems.ca/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Outside Cable Plant help!

I just tested by bypassing all the protection devices...same results...voltage still drops from 47.6 to 3.3 and back....

What is your loop ?

What is your resistance on one given pair?

It must exceed the limits, our it would fly.

VOM will have your answer to this puzzle

I did not check the resistance. To do that would I remove say one pair at one end, twist it together and put my test leads on the other end? And as far as testing from each side to ground, I am not sure how I would do that.

Yes, that would be one test. Remove the wires at the jack and at the other end, preferably at the 66 block at the PBX. With both ends open check the resistance from wire to wire then from each wire to ground. The ground could be something like a electrical recepticle plate or ground prong, cold water pipe or the ground for your protectors if you are near enough to reach it with your test leads.

After you do that twist together the end at the jack then measure the resistance at the PBX end from wire to wire.

Let us know what your results are.

-Hal

Thanks Hal...that will be tomorrows project. I have called in a favor and gotten the help of an experienced OSP cabler for Monday.

What kind of tolerances am I looking for in the resistance tests? I think I did run resistance on several pairs that were open and got 0 ohms. Am I looking for 0 ohms and what is the maximum acceptable resistance or do I need to get that from the Avaya Definity specs?

Nothing to do with Avaya, you are testing the cable.

I think you are a bit confused here as to how an ohmmeter works and that may be part of the problem- open is not 0 ohms unless there is a short close to where you are measuring. Open should be infinite or many megohms at least depending on leakage. 0 ohms is a short like when you put both test leads together, open is when they are apart.

Another point is that you probably should be using an analog "kick meter" for this as it's 45 volt supply can show up leakage problems that won't happen with lower voltages from digital multimeters. Digital ain't always the best solution.

-Hal

Thanks for the clarification and quick ohmeter lesson. I'll put this to use tomorrow...

Yes, we have Avaya Merlin Magix systems that are pushing Analog and digital stations 3000+ feet that is spliced several times from the station back to the control unit across cat3 and cat5 and probably some that isn't even rated.

So more than likely it isn't your Definity. It's your wireing. Do you have a cable tester for cat3 to run a cable test with?

I have a microtest pentascanner that I just picked up am still learning to use.

Velcro:

A Pentascanner is not used to test OSP cable whatsoever. Don't wast your time trying to do so. BTW: Are you SURE that you really have CAT3 buried six-pair? Most OSP cable is CAT "Nothing" with a few exceptions.

Even if the cable is truly "category-rated", it will be with extreme distance limitations. You can install "category 9 cable" (joke) but it won't be certifiable beyond it's maximum segment length.

That doesn't really matter. You have another problem and my guess is a split pair. Since most OSP cable pairs aren't band-marked, when inexperienced installers terminate them (hey, you did admit that you aren't experienced in OSP), pairs frequently get split.

This is usually caused by installers not removing at least a foot of outer sheathing and taping the exposed cable core together to prevent the pairs from separating. It sounds like you are not using buried drop wire, but maybe standard PE39 or PE89 buried distribution cable. This wire isn't designed for those who aren't familiar with preparation for terminations, nor to be terminated directly upon protectors. It's designed for telco or OSP contractors. It's also the cheapest cable to purchase.

No offense, but tell us the truth: Did you buy the cheapest cable you could get? Could you have done this and possibly split pairs? We aren't going to beat you up, but I think that's what has happened here. We just want to help bail you out of the mess.

Over a distance of 1,100 feet, capacitance alone might still permit a digital phone to function partially, even with a cable fault. A lot can occur over such a distance.

My guess is that you have not followed proper sheath removal procedures and have split your tip pairs. I'll bet that all of the tip conductors are solid white, correct?

You need to take the raw end of the cable as it enters the building and connect it directly to the phone and use this process along the way to eliminate segments or components.

I don't like the use of protectors with "punch-down" inputs, like the Circa 2602 units, since they don't restrict future repair people from simply pulling a pair and bypassing the protector. Unless it's a sealed/secure splice chamber or a spliced input stub, it's not a protector IMO. It's hard to find that kind of BET for anything under 25 pairs though.

You are right on everything. The wire is PE89 and I will plead ignorance on whether or not it was the cheapest. I just described the situation to my supplier (who will remain nameless as they have been fantastic to work with) and this is what they recommended. it didn't seem cheap to me as it costs me nearly $500! I simply assumed that it was rated CAT 3. I also am quite sure you are right on the split pairs. I tried my best to remove the jacket neatly and keep the pairs together but they had very little twist if any and it hindsight think there is a very good possibility that pairs are split. Although the pair I am on now passed the wire map test...You are also right that all the tip conductors are solid white and as hard as i tried to make it look good where I removed the jacket the wire looks like sh*%..anyways, finally something that has me seeing the light at the end of the tunnel. THANKS