atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Outside Plant OSP Construction Protection for out buildings

What's the best lightning protection to use for a couple of out buildings that each have a Norstar key phone and a paging horn? Two pair would do it for one building, but the other also has a couple more phones and a dial up line, so a higher pair count protection is needed.

Main office to first building is about 400 feet. Next building is another 275 feet further.

This business is a rural grain elevator, so it gets it's share of lightning hits. Lots of equipment has been damaged over the years. I'm trying to minimize the future damage. I have protection on incoming co lines in the office, and on the pairs leaving the office, but this is mostly to protect the ksu and equipment in the equip. room. What should I use at each building?

Thanks!
Jim

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Do a Google search for "6-pair protector" and you will begin to see how many are available. The first hit is for an older one with gas tubes from AT&T.

Are you using overhead or buried service to the outbuildings?

Yoda, the question is.....are you protecting the stations or the cable?

Use 5 prong arrestors, an adequate ground, and make sure the arrestors are rated for the lowest rating that will still allow your sets to work.

Arrestors that blow are doing their job.

:thumb:

Buildings are connected with pvc conduit and 25 pair filled buried phone cable. I want to protect the tel sets, page horns, etc.

I've use ITW Linx UP-235 devices that replace the bridge clips, and have had good results (they do blow)protecting equipment. Recently I've started using Porta Systems 506 GT devices. These reset after a surge, so I don't have to make a long drive just to replace the Linx devices.

Should I just put one of these at each building? Is there anything that would go inside the pedestal?

Jim

Jim,

Not seeing the campus, there should be a BET at the KSU end and one at each building. This protects the KSU and the end devices. Porta does make several 5-pin devices for different applications. Gas resets unless it is a very hard strike. Nothing should be required at the pedestal except bonding and grounding.

Just remember .... bond and ground every thing.

Jim:

If the pedestal that you mentioned has a divider plate inside, a 9E1A-25 or RPT-25P protected block would be a great mid-span "shock absorber" located within the pedestal.

Remember that filled cable punched down on a 66 block is wrong and that the "bridge clip" type protector modules are secondary protectors. You still need a BET with appropriate primary protectors in order to complete the puzzle. With primary protection, the secondary protectors should not be blowing. Secondary protectors are not intended to be the sole source of protection.

As Ken stated, grounding and bonding is the key, and for 25 pairs, #6 copper is the minimum for the grounding conductor.

Thanks guys. There is a BET from telco at the ksu end of things. I believe I can use the Porta Systems 506 at each out building, and at the ksu end, where the buried cable leaves for the out buildings. (Ed: I do have the filled cable spliced to a 25 pair I/O cable in a separate splice box. The I/O is then punched down.)

https://www.portasystems.com/Protection/Packs/5pin66packsindex.htm

Now the questsion is: which module to use? It looks to me like the Delta is the best choice. Do I want Heat Coil, or Sneak Fuse? And finally, is the 230 volt version ok? There will be a Nortel digital 7316 phone on the end of some of these pairs.

https://helpdesk.portasystems.com/download/Copper/PSC_delta.pdf

Thanks for the advise.
Jim

Jim,

In my past experience I always had some type of sneak current protection along with voltage protection. Personally I prefer ITW Linx. Even with the cable in conduit it can still get a static charge when the ground takes a direct strike. At least if you protect both ends you will increase the protection. As yoda stated, be sure that the rating isn't to low otherwise the ringing will blow the fuses. Check with the manufacturer of the protectors as to the recommended model.

Bob
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