sundance-communications.com/forum Forums General General Telephone & Systems Information Lightning protection in multi site location

(Sorry for long message)
I have a newly installed phone system in Gainesville, FL - a big lightning alley. The grounding for the whole plant has been replaced in the last 8 months. In the last 8 months we have had hits that have fried different parts of the phone system's components. I am wondering if the phone is not properly protected.
We got a lightning warranty built into the project, so we are not out money - but I want to help the site and installer minimize problems. The plant will be down for two days while the installer tests and replaces parts.

What type of things should I suggest?
The phone system AC is connected to UPS. It appears the lines from NID to phone block are grounded.
How can we test that?

Is there other testing that they can do throughout the paths to ensure adequate grounding?
How should we protect the cabling from main office to remote site (500 yds)? Is there 25 pair protection devices? Since the sites are separated, the grounding for both areas would be on different paths.
Lucky for us, this is a clay mining plant, with heavy clay soil. The clay is used by customers to create spark plugs (the white isolator) - sarcastic comment there: we have major problems because the clay makes each area an island with separate grounds. I have to help them isolate themselves better from lightning. Each PC is plugged into UPS.
Should I get surge for telco to protect stations? How about the cards in the system?
Any helpful advice would be welcomed.

Put Panamax protectors on all of your incoming COs and both ends of the cable running to your second site. They do make a 25 pair protector. Panamax was recently purchased by another company, but I think they are still selling the protectors under their own name.

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Avaya Telephone Repair
Toshiba Telephone Repair

I looked on Panamax's site, but only saw desktop type protectors.
Are the protectors you mentioned on their installer side?
I probably missed it, but I was not sure if it is in another area.
Thanks,
Walter

Any type good sneak protector will work. Ditex work good on 66 blocks, just put in a ground bar and use them in place of your bridge clips. Another good one is Porta systems, You can get them from Graybar. Just remember to get the right size for what you're doing, you want the protector to an electronic set to clamp quicker than a plain old telephone, and if you put too small a protector on a plain phone it will clamp on ringing voltage.

As far as measuring your ground, take a known good ground (power neutral, power ground, metalic water pipe) and measure to your telco ground, should be less than 5 ohms if it's good. Than tie all ground together so you have no difference in ground potential. A difference in potential will blow up more stuff than anything else.


[This message has been edited by justbill (edited May 05, 2005).]

Ditec makes some good protection, you may want to consider a outsidee plant "can protection". I have 2000+ port PBX in Orlando that has multi buildings and multi pedistal infrastructure. We lose 30-50 line cards a year due to lightning. We cut down on the lightning by Putting in Gas fuse protection with a low 240v clamp voltage. on both ends of every feeder cable. And ground everything,AC with surge supression,co,data I/O, and especially the far ends. Lightning is like water it follows the least path of resistance, we found that a hit on a remote building would travel back 1-2 thousand feed thru cable and knock out cards.

We get a lot of lightning strikes througout the year as Singapore's weather is hot, humid & with a lot of rainfall. Most buildings have lightning rods built in. However the problem is when the lightning strikes in between these buildings and hit the cables (or the metal roof of the walkway interconnecting these buildings).One of our customer was hit this way and it caused a few costly Printers linked to that cable to be damaged. They engaged us and we proposed earth grounding for the metal roof walkway, earthing the metal trunking enclosing the cables and putting in lighting arrestors at both ends of the cable (reterminated both ends of the cable into a punchdown block eg. ADC Krone & plugging in a lightning arrestor module into the Krone block). We did this about a year ago & since then all is well even though the frequency of lightning strikes in the customer's area is same as before.
Just one example as there are various ways to resolve this lightning problem but I guess a lot depends on your environment & type of problem. Regards.

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https://www.cablemaster.com.sg

You are in a classic situation due to the sparse spacing of facilities. This calls for more than just "off-the-shelf" punch down blocks with protectors. You need 'real' protectors and 'real' outside plant installation practices. I don't know how eleborate the inter-building cable structure is, but the ONLY way that off-the-shelf (ie: Panamax, Ditek, etc.) devices can truly handle tremendous inrush currents is if they have adequate primary protection installed ahead of them.

Primary protection, like the terminals installed by the telephone company are designed to provide "personnel and property" protection only. Secondary protection is required to protect sensitive electronics which is what you are trying to do.

Black-sheathed cable, proplerly spliced and bonded must be your primary transport medium. An indoor cable pulled in a conduit is not outside plant. Many installers think of water only when placing cable underground and just rely on PVC conduit to "keep it indoors". ALL cable must have telco-quality sheath, like PE-22,39 or 89 to handle any long runs. The cable sheath must be bonded with proper bond clamps across splices at at terminations. This bonding of the entire wiring network provides your wiring with a metallic "jacket" to divert transient surge currents traveling through the soil. Of course, all of these cable sheaths must be grounded at EVERY termination to a known good ground. NEC requires that all building steel be well-grounded, so rely on that, not water pipes or conduits for a ground point and use a good clam that bites into a steel framing member.

Your primary protection (at each end of every cable) must be something designed for exposure to outside plant. The "off-the-shelf" punch-down blocks and devices are not real primary protection; they are more of a secondary protection design. True primary protection, such as Avaya 489- type protected entrance terminals using gas or solid state plug-in modules are what you want for primary protection. Then, connect the appropriate Panamax or Ditek devides behind the primary protectors. You want this anyway, because these protectors can't be bypassed. Punch-down protectors can easily be bypassed by pulling the pair off the block, or substituting a protector module with a bridging clip. All it takes is one weak link to ruin your day.

One last note, always use #6 copper wire for ground connections to the primary protectors and for bonding across splices. Outside plant cable sheath is the electrical equivalent to a #6 and if you comprimise this by using smaller grounding or bonding conductors, you are turning the whole network into the smaller wire size.

As a last result, you might want to check with the power company's customer relations department. They frequently have people on staff who will assist you in checking for "real" grounds. You always want every ground connection to be no more than 1 volt difference which is easy to measure if all of your cable sheath is bonded properly.

This is probably a lot more information than you needed, but I am a real stickler about proper outside plant cable installation. Far too often, the secondary protectors or the equipment takes the fall for improperly-installed inter-building cabling. If it was installed properly, the secondary protectors might not even be necessary.

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Ed
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How come there's always enough time to go back and fix it a second time?

I aggree with ev607797. If you're having that many issues, you'll need primary & secondary protection. Paul144 was probably refering to this https://www.itwlinx.com/home/default.asp. ITW Linx purchased most of the Panamax line.

What type of phone system is it?

Thanks to everyone for the great info. First time posting here and BAM - mucho info. :-)

I will have to talk to the installers about the setup. Ironically, they are electrician group that installed plant-wide grounding for elec system. Our plant was circa 1909, with two wire throughout. They replaced with deep grounds installed and three wiring throughout.
I will talk to folks about measuring the Ohms at the various points. I have seen some other posts about other measurements. I am curious what to look for: ohms only, or other measurements of final system.
If we go and get Primary protection, I want to make sure it is installed correctly and giving protection. I hate to wait for next storm to see how it turned out.
Thanks again.

Take note to what "justbill" said about a potential ground difference. Whenever you are working with 2 different buildings with separate electrical systems, the phone wiring between can actually become a current carrying conducter when there's a ground differential. I've found that in some cases grounding at only one of the two buildings can solve the problem. If this is not possible than look at high end surge protection for phone & also make sure the electrical panels have primary protectors on them. Innovative Technology is the place to go. I've never had a problem after following their design & installing the system.
https://www.innovativetechnology.com/