lightning protection 1

[Aholmes]

Hello. I am hoping someone can point me in the right direction. We have a campus LAN with about 200 users housed in 4 campus buildings. Each building is connected via fiber for data and a 50 pair of copper for phone. The LAN has been operational for about 10 years. In the hub wiring closet where everything terminates we have a Nortel PBX, 10 servers, a large 6xxx Catalyst . In the 10 years that I have been here we have been hit by lighting 5 times (the grounds around us). Each strike has fried a segment of our network at the endpoint (never in the server room). The phone pair gets fried and ruins the phones and NICs get fried. Also, our fire alarm panels get nailed. I am under pressure to get this under control because it costs us about 25k each time. I have UPS on everything central and powerstrips out at the desks. Can someone tell me where I should begin my prevention program? thanks so much.

 

[mikeydidit]

J-STD-607-A  
Title  Commercial Building Grounding (Earthing) and Bonding Requirements for Telecommunications (ANSI/J-STD--607-A-2002)  
Committee  TR-41.7  
Published  October 2002  
Category  Telecommunications  
Description  The purpose of this standard is to enable the planning, design, and installation of telecommunications grounding and bonding systems within a building with or without prior knowledge of the telecommunications systems that will subsequently be installed. This standard also provides recommendations for grounding and bonding of customer owned towers and antennas. This telecommunications grounding and bonding infrastructure supports a multivendor, multiproduct environment as well as various system installation practices.

This book could save you a lot of money. You are more than likely taking hits because your cabling (copper feeds) are not at all or poorly bonded and grounded. You dont have to worry about fiber because glass is not a conductor of electricity. Get eveything properly grounded and your life will be a lot simplier. (At work) anyways.


Hell, there are no rules here - we're trying to accomplish something.
Thomas A. Edison

For the best response to a question, read faq690-6594

 

[macphoneguy]

I would agree, I would get that referance or ieee-142, I would read it along with some spec books form places like Anixter/graybar or any number of other electrical distributors and compair it to your layout, some of the manufactures like Panduit have a simple graphics to summarize what it should look like, I'm not sure where I would start other then to itentify what you have in each building and how you would interconnect the grounding bus bar, it may seem like alot cost wise but if you are going to stay in the building for a while it will save you in the long run,

 

[mikeydidit]

I would bet (almost) that thier is cabling running underground that is at one point exsposed to the outside. This cable more than likey does not have any protection on it and is not bonded and properly grounded to an approved ground.

I had this same problem years ago when I started here. I got to work on a lightening hit Demension 2000. Not fun guys. When we upgraded to the Avaya I went grounding crazy, but I have not taken a hit on this system in 14 years. I went as far as driving a grounding rod in the corner of my building and running #6 copper back to my equipment room. Made my grounding bar off that and a ground from the electrical feeder.

I really miss all those calls in the middle of the night... Yeah right..

Hell, there are no rules here - we're trying to accomplish something.
Thomas A. Edison

For the best response to a question, read faq690-6594

 

[Aholmes]

thanks so very much. This will help us tremendously

 

[SYQUEST]

You can also check with the local inspector or Authority Having Jurisdiction for some guidance and requirements along with the appropriate sections of the latest copy of the NEC.

Hope this helps!

....JIM....

 

[GMgerry]

Also check the Main Building Ground in each building and insure that is also grounded/bonded properly. You may wan to call in an expert testing company (get a good one) and have them test the grounding system. An audit of the distribution system may be a good process too.

I had a similar issue. The building was in a downtown area and when the wind blows very strong the switch would act up. Crazy talk you say. But wait, little did many know that the building had the top two floors added on. The PBX was grounded to the building steel but the steel members were no bonded correctly. So when the wind blew the building moved the potential changed. 900 feet of ground wire later....all was good.

 

[oldtimerbob]

You should have 'fused blocks' at both ends of the copper cabling where they come into the buildings and these should be grounded to a good 'earth' ground, not just a common building type of ground at both ends also. A blown fuse is a lot cheaper and easier to replace.
Normally these are installed by the phone companies when the cabling is, but sometimes 'in house' doesn't. ( Since you did not mention this in your posting, I thought I would put it in).
Another point maybe other items, such as antennas on the buildings and you should address them also. ( A good resource here maybe you local Amature Radio Club for guidance).
Good luck
Robert

http://www.globusinc.net

 

[Aholmes]

all this input id really going to help us. I really appreciate it. Should a regualr electrician be called out to test the grounding system or is this a speciality?

thanks again!

 

[SYQUEST]

Again, all of the above is covered in the various sections of the NEC. A competent journeyman electrician should be very familiar with BONDING/GROUNDING, but it never hurts to check references!

....JIM....

 

[GMgerry]

Find someone that does power quality audits. They do not have to be an electrician. But you may want an electrician (CYA) if you open any panels or plates. Must journeymen confuse grounding and bonding. Get a pro, it will be worth it.

 

[SYQUEST]

That is why I said "competent", because "some" do NOT know the difference between BONDING and GROUNDING!!!

"Some" think it is the same thing! (And "some" is being very kind.)

....JIM....

 

[Crowtalks]

You may want to swap out the protection modules in the terminals in each building from the 235 volt modules to 75 volt modules on the pairs that are supplying power to system phones and devices.

If some of the PBX phones require 120 volt ringing, then 75 volt modules would not be adequate for those.

Also, on your equipment, place your UPS's behind surge protectors because a protector can't protect until it sees the surge, which means some of the surge (lightening) voltage has passed before the protector could shut down and divert the voltage to ground.

 

[GMgerry]

You should not use a surge protector with a UPS at all. APC for one voids its warrenty if you do.

 

[RandalSw]

Lightning not only burns up equipment...It kills.

What you need are 50 pair entrance terminals. 3M makes about a bizillion different types, indoor, outdoor, with crossconnects, punchdown or twistlock, etc.

Grounding is what it says, hooking to an available ground.
Bonding is making sure all your grounds have the same potential. That means using #6 (depending on the length required) to strap power or other ground sources to COLD water pipes as close as possible to where it comes out of the ground. Ground rods are notoriously bad grounds.

If you have any T1's on copper, you MUST HAVE the 235V modules. Normally, they are red with a blue tip.

 

[RandalSw]

I worked as an installer repairman for GTE. I had a customer report that the dog howls every time the phone rings. Yea, right. I get there and test it and sure enough the dog howls like crazy when they get a call.
The dog is standing in mud with a chain collar tied to a chain tied to the ground rod at the lightning protector.
The protection was bad and was giving the line a ground on one side. The ground from the ground rod (not bonded)was not as good as the dogs feet in water. I bonded the rod and replaced the protector. If lightning would have struck, that dog would've had wings.

 

[GMgerry]

I must disagree with the cold water pipe. That was a staple long ago but no more. Besides the fact that code requires attachment to the main building ground, cold water pipes are becoming more and more plastic and unreliable as a simple ground rod. Code now requires a ground mat be installed outside the building. This mat size on average is a 10 x 10 copper mesh about ten feet below the surface. This is than bonded to the building steel, cold water, electrical ground. This gives all grounds the same potential.

 

[LamoniDave]

I understand that GMgerry's point about "all grounds [having] the same potential" is important. Having multiple systems in the same building connected to different ground points means that a piece of equipment (or a person!)connected to more than one of these systems could carry current to balance the potential between the two grounding systems. Specifically, this means that it is NOT recommended to have a separate ground rod for an independent telecommunications grounding system.

 

[Crowtalks]

GMgerry: APC may void the warranty but we have some areas where lightning would eat up systems and the UPSs on a regular basis, until I started putting the UPS behind surge protectors.

Void a warranty on a $200 item to save $2000 worth of equipment, I'll do it every time...

 

[RandalSw]

Code now requires a ground mat be installed outside the building."
Is this out west in sandy soil?
The only place we installed grounding grids were CO's, remotes and cell towers. Those had ground rods cad-welded to the grid. Poles, pedistals and crossconnect boxes used 10ft ground rods.