atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Outside Plant OSP Construction grounding between buildings

I have a 50pr cable carrying phones from a building 300 feet distant from the NEC EliteIPK phone system installed in my building. This cable is buried (about 4 feet) and in plastic (PVC?) electrical conduit. The pairs are protected at both ends with Corning 3B1E protectors which I believe are gas-tube type. We have continuing problems with cards in the IPK being damaged because of lightning. The shield on the 50pr cable is grounded on both ends. I have always understood that it is to be grounded on one end only. I have two questions;
Should the cable be grounded on both ends and should I replace the current protectors with Solid State types?
I appreciate your hosting a FREE service such as this board. I have read many of your responses and deem you to be very knowledgable and "to the point". Thanks.

The 3B1E modules are carbon block, not gas tube. You may want to replace them with 3C1E's to provide gas tube protection. Then, provide secondary solid state protection through the use of ITW units or something similar. These should be installed closest to the equipment. Yes, a #6 ground should be connected to both ends and bonded to the building's metal framing or electrical service grounding electrode.

definatley need the secondary

we cabled two buildings for a guy that refused to pay for secondary , he felt primary would be more than adequate (he had electronics background )

so we sent him a letter advising our concerns and proceeded with the install

two storms , two billable service calls and 30 bad ports later it was "how fast can you get that stuff in ? "

never lost a port after that

BTW welcome to the board

who says its free ?

stick around and help out

I'm sure you have a answer one of my need someday

Ed, thanks for the reply.... I have two additional questions relating to your post. 1. You said to replace the protectors with gastube... why not solid state? 2. What is an ITW unit... and does it go on the equip. side of the current protector box?
As to the FREE comment.... I have 40 years background in mainframes, PC's, LAN/WAN, and DataComm. If I can be of service, please ask.
john

Ill let ed handle the gas tube vs solid state question

heres the ITW lynx site they took over the panamax line

Well, you certainly can use solid state modules if you like, but they are significantly more expensive. In my experiences with using them, I haven't noticed any notable improvement in protection levels. It seems that gas tube does a good job of providing property & personnel protection while taming the surge. The secondary Panamax (ITW Linx) units are then able to do their jobs as secondary protectors. Yes, these units do connect on the equipment side of the building entrance terminal.

On the secondary, check for the clamp voltage, especially if you are running digital circuits through it.

My $.02 worth.

Ken, Ed, et.al,

After talking to sales engineers and techs, the recommendations are....
replace the carbon block primary protectors with either gas tube or solid state and provide secondary protection with ITWLinx up3 devices.
We have fiber buried along with the 50pr copper running to the remote building. I have a quote to place a KSU at the remote building and tie them together with fiber. I know this would eliminate the problem but the cost is around $6500. It looks like doing as everyone suggests with protecting the circuit would cost around $2500.
My question is, if adding a second KSU and connecting the two with fiber would provide 100% protection, what percent protection would I get with the other alternative?
john

Since its bests guess I would say PROPERLY done the gas tube primary and itw linx secondary would be in the high 90's for protection,

you need to be sure your gas tubes are properly grounded and you need to bond the 50 pair

Would fiber be 100% ?

Nothing is warranty, by who?

If you put proper primary and secondary protection you will be fine.

If you match proper protection to the source you
you are treating it will be fine. (clamping voltage/proper grounding )

You must take into the picture what the voltages/current of the station ports are rated.
What the voltage is when ringing current is applied etc. IF - IF - IF.

If you leave just one "IF" out of the picture, then you are screwed.

I would be very careful not to build a ground loop at this site. (another situation).

When you leave one little crack in a roof, the roof will leak.

You must look at "ALL " elements as one is just as important as the other.

Good luck. Its FRIDAY the 13th.
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