Questioning the need for grounding on new cable between buildings

[GregH1]

We recently install a new 200 pair cable between a couple of buildings. We took on the cut-over because we wanted to be intimately aware of our phone system. We've been struggling with problems, primarily static on the new cable. My question, how important is it that the 200 pair cable's shield be grounded. Would this help in getting rid of small amount of stray static electricity and improve telephone performance?

 

[Firebird Scrambler]

What type of 200 pair cable did you use?. Was it underground external cable or was internal cable provided?. Was it put into a duct on it's own or was it placed along side other services?.


Firebird Scrambler
Nortel Meridian 1 / Succession and BCM / Norstar Programmer in the UK
Advance knowledge on BCM support

http://www.linkedin.com/in/davidbromley

 

[bhassell2000]

if its not grounded it will be interesting when there is a lightning storm and it gets hit

Thanks,

Buddy

Linked in Profile

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[Loopback55]

Lightning protection should be installed at both ends and grounded whether it is underground or on telephone poles.
Call a local electrical or telecom supply company.

 

[KCFLHRC]

Yes it should be on lightning protection and grounded and no that is not what is causing the static.

 

[GregH1]

The cable is a black sheathed cable with a wrap I believe is aluminum. The outer sheath is marked with the footage measurements and a telephone symbol. It also has two ID's GCC010J2 and PE-89-AL. As for the cable route, it is all in the inside of buildings nestled neatly in a wore rack with several other bundles of telephone and cable TV. When going from Building to Building, this is done via our interconnected tunnels. Hope this helps.
Sorry for the delay, I've been off the past few days.

 

[GregH1]

KCFLHRC - you indicate that this is not causing the static. Where are the most obvious sources of static? I know there are several pieces to this puzzle.
We have, of course, the PBX itself and the cards therein. Then the TN's location, jumpers from the TN's to the Building-bound pairs, the long haul cables between the buildings, the data closet's 110 blocks, the jumper in the data closet and the Gigabit blocks, then the wiring within the building and the final termination. But where to start. I am an IT guy that has gotten thrown into or onto the phone system. I know so little of this area. Any and all help is appreciated.

 

[KCFLHRC]

What type of phones are you having static trouble with? Analog or digital?

Thanks

 

[bhassell2000]

static only in remote building on far end of new cable? Was there static before cable replacement?

Thanks,

Buddy

Linked in Profile

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[GregH1]

Static was there before and after.
Static is highly noticeable on some analogs and a few digitals.
Some of there had static before and some did not.
We're going to try to isolate the phones at the PBX, then the lightning protection in basement, then lightning protection in the far basement then the 110 block in far end.
After that it's either the gigabit wafers, building wire to the terminal, the terminal or the phone itself.
And yes we've already tried different phones on the lines with the problems. Different analog and digital, different types and new base cords.

Just really frustrating at this point.
Not that weather should have anything to do with our new cable, but on some lines when it rains it gets worse and on some rain seems to assist the signal.
Go figure.

 

[bad69cat]

Do you have any overhead high power lines that could be inducing noise/voltage on the cable? If so try grounding the shield on just one end of the cable...... on it own ground if possible.

 

[bc1111]

Do you get the static if you punch down a phone at the mdf?

 

[Loopback55]

About the lightning protection. They make co many types. If you can, try to find one that has a common type of connection to your MDF.
If you MDF is 110 see if you can get a 200 pair terminal with lightning protection with a 110 type of connector.

 

[golfdoctor]

Does the problem exist at the main MDF at the TN prior to the HPFL's ? (previuosly mentioned by bc1111) If yes issue with PBX if no then issue further down the line...

If lightning protection is being utilized what is meant by "Gigabit wafers" The cabling for comms or telephony is usually Cat 1 or 3 shielded and or greased for entrance facilities depending on the routing implementation. The lightning protection for this type of cabling is different than the lightning protection for lets say a Cat5e data copper entrance solution. Cat3 cabling requires Cat3 lightning protection, Cat5e requires Cat5e data protection.(different current and voltage levels depending on the device application) If the cable is shielded it should be tied to the MDF ground which should be connected to the building ground.

The desciption associated with the rain possibly suggests the buildings are at different ground potentials.(MDF perspective) If the original cabling and the new cabling are exhibiting the same static problems then something common must be causing the problem. In the tunnels is the cable in conduit or cable trays. Is the new cable taking/sharing the same route and space as the old cable route?

Maybe terminating the telephone(s) at the remote buildings MDF and bypassing the lightning protection (at both MDF's)on a couple of pairs will assist in determining where the problem exists ?

Only some thoughts....


TGD

 

[GregH1]

Sorry - I've been off a couple of weeks with my granddaughter.

bad69cat - No ariel lines. All cables are in open trays with soon-to
be abandoned 400 pair cable. However the trays do run through some
congested mechanical rooms.

bc1111 punchdown at the MDF is clean, no static

loopback55 All lightning protection was in-place before I got here.
All areas use 100 pair boxes ganged to accomodate the cable to be
protected.

GolfDoctor: For most of the connections, we're finding that a port
on one card here and a port there on another card there.
Not seeing errors that help to isolate the problem.

With our company someone decided a long time ago to use Gigabit where
the lines go out into the building. This way you have the 110 black
bringing the signal into the wiring closet and the gigabit block
taking the signal to the office. It's not difficult to work with,
just that the punch tools are expensive and hard to find.
The old cable runs outside our building through the ground, then back
in near the point where the building is joined by tunnels to outlying
buildings. I suppose that they wanted to keep the phone wire from
causing more congestion in the basement where there was already
planned for several utilities. Thereby hopefully protecting the phone
cable. However we found out, during the new cable install, that a
backhoe operator hit the 400 pair bundle, not once, but twice while
the company was terminating the cable.


Thank you all for the help. I think with the suggestions and hints
provided here we have a good source for finding this critter and
exterminating it.