Estimates for cable pairs and spares? 1

[MsGrace]

I have a project to spec out and am wondering if there is a standard for estimating overages or spares for telephone pair wiring.

Note: All analog phones, UTP copper pairs distributed throughout the building; horizontal distribution to basement closets then verticle distribution to each floor above.

I am going to increase the number of telephone lines from 1900 to 4500 in a building. What would be a good percentage for spare pairs in these cable estimates and is there an industry standard for such estimates?
I am putting in a 20% overage on the distribution of these copper pairs but my manager wants some justification (other than just me saying this)or some reference to an industry standard for these sort of numbers.
Can anyone help?
Thanks for you attention and support.
Regards,
MsGrace

 

[fonman]

You didn't mention how old the existing cable is, but look at the percentage of increase in required cable (no spares). Now, try to project growth over the next 10 years. Adding 10% to your projected growth will probably hold you fairly well, but changes in the economic climate for your company could affect your projections. As you will see when you deal with the cost of adding pairs, it is much less expensive to add them now than to add them later, because you did not have enough in the first place. Good luck.

 

[MsGrace]

Thanks fonman... good info.

Regards,
MsGrace

 

[Darboy]

I allways try to install at least 25% spare capacity on each voice cable, this allows for future expansion and allows for what I call maintenace pairs that can be used to replce faulty pairs.