Keep frying ports and phones

[executone]

Norsatr MICS and phones are on station expansion modules

Went to a SBC customer that keeps frying ports and phones on 2nd building, feed on 200 pair feeder. The cable has carbon protectors and is grounded properly, but they keep loosing equipment after storms.
I think I should put some extra lighting protection at each end. Either gas or electronic. What would you recomend? Also, at what trip setting would you recomend? (25 volts, 48 volts, etc.) I belive phones are at 15 to 26 volts across tip and ring.

Thanks,
Jeff

 

[franklin97355]

Do you have a UPS on the system? Just wondering.

 

[DToolsDesigner]

Do you have fusible links on the incoming pairs or just the protectors?
When you say put extra lightning protection at both ends, I take it this is a campus situation? How are the cables run between buildings? Conduit? Direct burial?
Do you currently have protection at both ends?
To what is the protector bonded? Are all metal parts bonded i.e. the switch case?

My first guess based on the limited info available is perhaps you have a grounding and bonding system that is not tied together. i.e. Two separate ground sources, is that possible?

Just adding protectors without finding the true cause will not solve anything.


Richard S. Anderson, RCDD

http://www.servamatic.net

 

[mikeydidit]

I think Richard may have you on the right tract. Look at the 200 pair to insure it is bonded and grounded properly. Your protectors can be grounded and the cable not bonded and a ground ran to it. Seen it before and it still doesn’t work.


Mikey

 

[OldPhoneGuy]

This sounds to me like a cable bonding issue. I ran into the same thing several years ago at a college campus. Every time there was a thunderstorm in the area they would blow phones and circuit cards. Found that the campus cable was grounded but not the sheath was not bonded.

 

[executone]

Yes they have a UPS on equipment.

The cable is bonded and the protectors are grounded also. Electrician installed isolated ground for all the voice and data equipment at both buildings. I tested ground with volt meter and AC outlet. They have Circa Telecom protectors (part # ct3bie bal). From my research these are carbon protectors. The cable is buried cable between two car dealerships.

Since I did not install and am going be what customer was told/sold by SBC. I thought I would put in Porta Systems gas tube protectors, and trace ground wires at both ends to verify it is properly installed. I had one customer that Telco ground wire was hooked at Demark, but when I traced it out it stopped in ceiling (not hooked to anything).

Thanks for the input, will double check bonding/grounding.

 

[DToolsDesigner]

When you say the electrician put in an isolated ground, does it connect at some point to the main building grounding system?
Isolated grounds should be tied to the grounding bus bar in the main electrical service, not isolated to their own ground rod.
I am sure if it was installed by a reputable electrician he did it right, but you should always verify for yourself.
I have seen guys put in a separate ground rod for isolated systems, which is a code violation.


Richard S. Anderson, RCDD

http://www.servamatic.net

 

[executone]

Ricard,

I agree with what you are saying, and need to go back to customer location to verify.

I have only been there once and was informed of the problems while onsite to do some other work. It is not my customer, but think I can get them if I solve this problem.

Thanks again for all the help!!
JJ

 

[executone]

Richard,

I agree with what you are saying, and need to go back to customer location to verify.

I have only been there once and was informed of the problems while onsite to do some other work. It is not my customer, but think I can get them if I solve this problem.

Thanks again for all the help!!
JJ

 

[DToolsDesigner]

Best way to get a customer for life, solve a problem that is costing him money, especially when others haven't been able to.

Richard S. Anderson, RCDD

http://www.servamatic.net

 

[jerryreeve]

I had an almost identical problem (is that my customer?) and about a month ago I got a transguard lightning protector with 57V trip on it. this uses something similar to a varistor and goes in parallel with the pair to the phone system. it is not a gas tube or carbon block that need to be replaced every time it trips.

FYI I found in te book where norstar states that their keysets should not be used out of building.

a note also the M series phones almost never had a problem but the new T series seem to be less protected.



JerryReeve
Communications Systems Int'l
com-sys.com

 

[dhnl]

You could install a multimode fiber line along with one of these & a 0x16 cabinet

http://www.mck.com/solutions_products/products/multi-user_extenders/datasheets/module_extender.pdf