Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Lightning/Surge Protection at Stations? 1

Status
Not open for further replies.

icsaidblindman

Technical User
Jul 15, 2002
40
US
Well another major storm hit a customer who happens to have a series of buildings on a school campus. These buildings are inter-connected with a MICS and all is well. Except, once or twice a year a lightning storm will knock out a couple of stations or more. There is protection for each pair at the entrance to each structure (installed by SBC) and bonded to a strong ground. But we continue to lose some phones.

Is there a RJ-11 jack with protection anyone can recommend or share any other suggestions?

Thx

Craig
 
you will probably need a faster reacting fuse block ... so that it blows before the surge reaches the KSU/phone ...graybar kinda places must have those. usually the SBC facities are sufficient.

are the stations wired with overhead cable/ underground cable?

is it the phone getting damaged or the port in the KSU?
 
are the phones powered externally using SAPS? maybe thats the culprit
 
Thx for the response.

All wiring between structures is underground. Only stations are effected, luckly no problems with the KSU. Also, all power is from the KSU.

Thx again for the help.
 
BTW, does anyone know of any RJ-11 jacks with suitable surge protection?

 
I would put building wiring protection blocks in at the entrance of all cable from undergound locations.
 
Thx VencomRob and Senk1s for your replies.

I have installed protection blocks at each entrance and still have random issues at two of the four buildings. I plan to double check the bonds of the blocks to to ground and confirm these are all good. Other that that, I'm baffled.

Does anyone know if there is an RJ-11 jack with surge protection buit-in?

Thx again,

Craig
 
I have heard of rj11 jacks with surge protection but they were $50.00 + up each (not too cost effective).

The most cost effective way is to have your lightning protection modules evaluated. Your vendor probably installed a 4B1E gas tube 250V module- which is usually sufficient. Nothing will stop a direct hit (I have seen buildings blown apart & have seen OSP Aerial cable that looked like someone took a machine gun to it).

I made the mistake once of installing the highest value protection modules without the PBX specs- then the digital sets would not work.So I used the standard modules for the digital sets and highest ones for all other pairs.

Check with the manufacturer of the lightning protection modules- give them the norstar telephone specs listed in the manual.

They could probably recommend a higher value solid state module to use. They might only cost you $10-20 per pair. Try them on your active set pairs.

The problem with a hit- is the phone might have been ringing or usually someone is on the line during the storm. I run into that alot in campus environments. That is why they tell you NOT to be on the phone durung a storm the lightning could pass right through the phone.

Steve
tele-dataservices.com
 
i had same problem ..the only thing that worked were the adapters on rj11...found norstar phones are not very tolerant of even the smallest voltage spike...tried changing fuses at both ends of feed cable.. was useless...we installed a new earth ground...useless...nortel will not even discuss issue...they dont support off premise sets...may be change digitals out for analogs...also if its cost effective extend fiber for a stat module to the out building

ONLY 21 WEEKS TILL SKI SEASON STARTS
 
I had one customer that seemed to lose a set on every storm, but only in the outlying buildings. last year I put a TRANSGUARD lightning protector on (57 volt protection for Norstar) and havent heard from them about lightning since.
The Transguard goes in parallel with the station pair and just routes everything over 57V off to ground.

I didn't have much problems with the M series but the T series seem to be more succeptable to lightning problems.

JerryReeve
Communications Systems Int'l
com-sys.com
 
I've done what JerryReeve has done but used 30volt gas protectors for all my off prem digital sets. No problems. This is an absolute must. Anything else will destroy sets.

PhM

 
almost all building codes require gas tube protection at building entrance anyway. I had building protection but still ended up with the transguard units.

JerryReeve
Communications Systems Int'l
com-sys.com
 
This is excellent information! I have another option that I would like to mention that has proved itself as reliable for me. EDCO out of Ocala, Florida makes the COHP series protector that is a very good product. The COHP protects against over voltage transients with silicon avalanche components and any voltage that goes above the modules rating is sent to ground and the module resets as soon as the surge is gone. Take a look at the web site and I think you can get COHP-15, 30, 50 or 60 depending on the telephones voltage. They also have a RJ11 version that I noticed on their site. Good luck!
 
Thank you to all for your help!

I'll double check the type of protection at the entrance to the building and look to add a gas tube to ground, or something similar too.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top