atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring cat 3 or cat 6

OK, the question is-
Why not use cat 6 instead of cat 3 for a phone line?

Before you guys pound me let me 'splain-

I read a lot here and there are many that advocate cat 3 for phone. The CGs are taken to task for using cat5/6 for everything. Where I work they pull cat 6 for everything, but they say that is due to IP style phones(CGs run the show here, but the 'phone guy' has a telco background). Is the cat 3/POTS VS cat 6 issue something that is related primarily to residential? Is it mainly a code thing for some of you?

I would just like to see the comments because I like to learn, and I have a decision to make shortly-I have a pile of cat 6 that is no cost to me, or do I go and purchase a roll of cat 3 to run for a few POTS drops?

Thanks guys, you all have a really nice community here.

It's simple. Anything higher rated than CAT 3 for voice is a waste of time and money. Just tell them two CAT 3's trump one CAT 6.

If you're wiring for a full IP system than yes CAT 5 or 6 is required per spec.

I think he's talking about using left over Cat6 from his job to run drops in his house. Hey if it's free and it's long enough why not. If you have to buy it, Cat3 is fine.

The guys here like Cat3 for phones because it is easier to untwist and punch down on 66 blocks. Which is true.

They prefer 66 blocks to 110 because it is easier to attach butt sets and toners to 66 style clips. Which is true also.

Most system installation manuals recommend using 66 blocks. The ones I've read anyway.

Cat3 is cheaper than Cat5 or Cat6.

That's my 2c anyway.

Where I work they pull cat 6 for everything, but they say that is due to IP style phones

Maybe those CGs should learn to read something other than computer magazines. Most IP phones will work just fine with CAT3. No high bandwidth data transfers going on there. However if they are going to install it like data, terminated on a patch panel and 8P/8C 568 jacks on the walls they might as well just make everything the same. But that's not to condone using patch panels and 8P/8C jacks for voice.

From a telco standpoint we require a greater flexibility in utilizing the individual pairs of a cable. With data it's a given that all four pairs of a cable will originate from a 4 pair jack on a patch panel and run without interruption to a 4 pair jack on the wall.

In telecom we often need to use the pairs individually. One pair on a cable might be used for a phone with another for a fax machine or even another phone. There could be two and even more 6P/4C USOC jacks on a wall plate all fed from the one four pair cable. Back at the other end the cables terminate on a cross connect consisting of usually 66 blocks. There the individual pairs of each cable are readily available to be used as necessary, and can be easily connected and reconnected with jumpers to other 66 blocks as additional equipment is added or removed. Hence the name "cross connect".

Getting to the CAT3 vs CAT5/6 issue. As has been pointed out CAT5/6 is not needed for most telecom installations. There is a great cost savings with using CAT3 especially over CAT6 and especially if a plenum listed cable is needed. Also consider the higher cost of terminating CAT5/6 on 66 blocks due to the preparation of the cable with it's tight twists.

So if it were me I would go out and buy a box of CAT3 for a few bucks and throw that CAT6 in the scrap pile.

-Hal

If you have CAT6 at no cost to you run the CAT6. Why spend the money for CAT3 when you don't need to. If needed you can split the pair out of the CAT6 for other analog devices. If you are going to connect a ethernet device (PC) to the phone then use CAT6.

If you have CAT6 at no cost to you run the CAT6. Why spend the money for CAT3 when you don't need to.

Because CAT6 is not worth the trouble.

-Hal

"Why not use cat 6 instead of cat 3 for a phone line?"

~ Cat6 costs more than Cat3, especially in plenum.
~ Cat6 is more time intensive to punch down than Cat3, especially if it's 23ga or bonded pairs.
~ Cat6 is heavier and bulkier than Cat3, which means putting less of it on my truck and more effort hauling it up to the xth floor of a building.
~ Cat6 has a significantly larger OD than Cat3, which can present problems if the job is in conduit.

Without fail, every single commercial job I do that specs cat6 for telephone goes something like this: all cabling is to be Cat6, on Cat6 rated 110 blocks (more $$$), using Cat6 jumper wire (still more $$$), but terminated on an RJ11 wallplate (one pair) and connected from the IDFs to MDF using Cat3 25/50/100pr. :bang: :bang:

Most of that is n/a in a residence, but I still don't see the point in using cat6 for voice. Look at the cable coming into your NID - it's not cat6, it's cat-nothing. 50 or 100' of Cat6 past that will do nothing to improve the quality of service, and thus, is a waste.

Jack

If I didn't have to pay for it, I would use the Cat 6 - if I had enough of it to wire for Data too, while I was wiring for Voice.

Sam

Analog phones can run on about any 2 conductor cable.

VoIP needs data cables which should be Cat 5 or 6


Digital phones need 1 twisted pair which can be Cat 3, 5 or 6. Many digital phones are fussy about the length of wire so if you use Cat 5 or 6 then you can't run as long of cables because of the extra twisting makes the conductors longer. then the wire itself. Also a big problem is if you use a Cat 5 or Cat 6 backbone with 8p jacks and plug a regular 6p phone plug in it will work but you have no side support. If the phone cord is tripped over or pulled very hard it will twist in the jack and bend the pins causing problems.

cat 3 would be my first choice

if I didn't have 3 and it wasn't a lot of runs I would and do use 5/6 .