Hi All, I would really appreciate any advice on this issue:

We recently opened a new office about 700 feet from our old office and connected our phones in our new office to our nortel system at our old office via underground cat3 cable. Almost immediately, phones at the new office started dying - the display will dissapear and the phone will never work again, no matter what line it is connected to. When the phone that died is replaced with a new phone it works fine on the same line.

To date we've had about 12-15 phones die. The phones at the old office do not suffer from this problem even though they are all connected to the same system.

Our system:
MICS 4.x
Voicemail NAM
ACD NAM (cinphony)
4 POTS lines
1 T1 line
Combo Fiber/Clock card

I would greatly appreciate any ideas/advice. Our installer hasn't come up with any solutions so far.

(ps, we've been getting "ALARM 75" on the main set periodically but I don't think it is related)

Thanks!
Jer

Hi lwjer.

Welcome to the board.

Please complete your profile so we will know who it is we are helping

The ones you are replacing, are you replacing them with the new T series phones?

When you say underground Cat. 3 cable, do you mean gopher proof direct burial cable or what?

22, 24, or 26 gage cable?

Do you have all unused pairs grounded on each side?

How far in total from ksu to new phones, not just from the building?

If you were using 26 gage cable going a real 1000 feet I would look at replacing the cable. Who told you what cable to buy, your vendor? Someone in the office? A supply house?

I assume that the display dies AND the phone cannot be used for a call either.

Do you have any lightning protection?

Hi,

We are replacing the dead phones (they die completely) with the same model M7310 (not t series).

Underground cable - it is 2 x 25 pair cable bundles run though a 2 inch PVC pipe. The guage looks to be 24.

I don't think the unused pairs are grounded, they are just punched down.

It is probably up to 1000 feet from ksu to phones.

Lightning protection - the ksu is protected by our central building UPS. Other than this there is no other protection.

Thanks!

You must have lightning protection on both ends of the cable even if it is underground. And previously noted all unused pairs should grounded.

1000 feet is the extreme limit for any M or T series phone on 24ga wire. You can increase the distance by doubling up on the pairs.

should have primary (gas tube ) and secondary lightning protectin that is rated for digital sets .

cable should be bnded an grounded .

get somebody in who understnads outside plant to straighten out for you .

You have 50 pairs, how many phones? As telemarv suggested, using two or even three pairs for each phone will give you more power, remember the power to run the phone has to go that far on 24 gage wire as well as the data. More copper = more power.

I don't think anyone who wasn't an old timer would realize the scope of the job. People who just read a book and take a test don't get this information and don't offer it to you.

As everyone said, get an expert. If there is a Volt contractor in your area, they could do it. You could talk to some of the techs at the local AT&T or Verizon or whoever central office and see if they would come over off hours and do this.

My suggestion would be to use as many pairs as you can, ground the rest, and have solid earth grounds on both ends. Everyone above is giving you solid advice for free and it is worth much more than that.

Print this out and give it to Volt or a tech working out the central office or an independent.

Ditto what Skip said. You need lightning protectors for digital phones. We use ONEAC 6DP protectors on all digital sets located offsite of the KSU.

The Norstar series phones have a main "brain" I/C chip that is pariculary sensitive to power surges. Without adequate lightning protection at both ends of your underground cable, you will continue to lose phones on a very regular basis.
I would love to know who installed the cable without it....