Phone Block Wire Types

[rhislop]

Hi everyone. I need to rewire a real mess of a phone block area. There are twelve phone blocks in a space measuring approximately 36" x 48", with the Merlin Legend PBX adjacent to this area. The phone sets are anywhere from ten to 800 feet distant, on a campus consisting of one main office building and three other buildings. The wiring between buildings is the half-inch thick gray bundles of 100 wires (don't know the vintage or type).

I intend to have six phone blocks wired to the jacks on the PBX (let's number these 1 thru 6). I also plan to dedicate a phone block to each of the three outlying buildings (blocks A, B, and C), plus three blocks to serve the phone sets in the main building (blocks D, E, and F). I expect to use little gray-jacketed cables of eight conductors to jumper between the PBX blocks (1 thru 6) and the incoming blocks (A thru F).

With that background, my question is: Do I have to use CAT 3 cables for this purpose, or can I use the eight-wire unrated flexible phone cable at Radio Shack? The only CAT 3 cable I've been able to find is so thick that it seems it would just make another mess. I think the Radio Shack wires are of smaller gauge and untwisted, making the entire assembly smaller and more flexible.

Would appreciate everyone's input!

Thank you,

Roger

 

[TouchToneTommy]

Use cat-3 at a minumum. DON'T use untwisted 8-conductor cable, due to cross-talk problems. How many cables are you talking about? You can get 12 - 4-pair cables on each 66 block (66M150 split block), and it can be done neatly and efficently. You might want to consider having a pro do the work for you, or at least looking at some properly done installations to see "how it is done". (and remember, a lot of installations are sloppy; you'll know a good one when you see it)

 

[Bobg1]

I agree with tommy, if you don't have experience with how this should be set up, you really need to get someone who does to help. You don't want to run out to radio shack and get the parts, because they may be just as wrong as the mess you are trying to straighten out.

 

[Ghostin]

Are you using MLX series telephones. You can easily use 4 conductor cross connect instead of 8 conductor cable. The Legend only requires that the center 4 conductors be used unless you are equipping the phones with MFM devices. It will look better and it will be easier to change around than using cable as cross connect. As Bob and Tommy stated, if you haven't done a lot of this, get some help. Doing it right the first time will save you alot down the road. Where are you located? I have a pretty good contact list of techs around the country. Contact me below.

Zane

http://www.omni-comm.net

 

[TouchToneTommy]

4-conductor is fine for the cross connects, but the 4-pair station cables should have ALL of the pairs punched down on the block, and then the cross connects can be brought over to the Blue and Orange pairs (for an USOC 2-pair jack)

Not punching down the spare pairs will just turn the installation into a total cluster over time (voice of experience here; that's how I was originally taught and it didn't take long to realize that it was wrong and to start taking notice of clean installations. Now days I'm accused of being a prima-dona, and that's OK with me)

 

[rhislop]

Thank you for your input! I am glad to hear the wiring should be rated at least CAT 3. At least half of what I see in my room is not rated at all, which surprises me. I do plan on twelve 8-conductor punchdowns per block (both to the PBX and to the sets), and am planning on doing 4-conductor crossconnects to keep wiring to a minimum.

Can I ask you all what type of cable (company and part number) you recommend for both the PBX-to-block portion and the block-to-block cross connect portion? I don't want to use the bulky CAT5 cable I find at the store, and the CAT3 cables I've come across thus far aren't any smaller.

The "experts" we've had here before me used twisted pairs of single-conductor wires for the cross-connects (looks like CAT3 cable wires taken out of the jacket) and unrated cables from the blocks to the PBX. The oldest cables into the PBX are 4-wire and bear a CAT3 stamp, so they are probably good (and make me wonder if I should find something similar so there would be fewer wires to punch down on the PBX end).

Thanks again for all the advice!

Roger

 

[Pepperz]

Roger almost anything will do for phones. Data is another story. In some cases, you may even be able to use a coat hanget, but it's hard to punch down. Seriously, in your case, you may want to go with a specific solor of cable to helkp keep track of where you are. Otherwise shop for price. Try to get it in the box that feeds out untwisted cable rather than having it on a reel, ... just makes it easier to work with. TipHelp@charter.net