Telecom Cabling

1. Telecom Cabling Telecommunications cable types

2. Telecom Cabling • Cable types: Quad or JK.

3. Telecom Cabling • Quad cable is a typical residential style cable. • It may also be called “JK” cable. • It is called quad cable because it contains four conductors. • The four conductors are color coded as Green, Red, Black, and Yellow.

4. Telecom Cabling • There are times when it will be necessary to incorporate 4 pair UTP into a quad style outlet or plug. • The next slide shows multiple ways of terminating plugs using 4 pair and quad.

5. Telecom Cabling • Pin outs for UTP and Quad

6. Telecom Cabling • Note the use of “T” and “R” when discussing telephone circuits. • A telephone is simply a circuit like a battery. It has a Positive (+) and a Negative (-) part. • In telephony we use tip (T) to show positive and ring (R) to show the negative side of the circuit.

7. Telecom Cabling • Pin-outs RJ-11. Note that the center pins of a plug carry telephone signal.

8. Telecom Cabling • When simple premise is color coded, two-wire telephone plugs or the first pair of a multi-pair plug commonly have the tip wire coded green and the ring coded red. • In four wire plugs, the second pair isblack (tip) and yellow (ring).

9. Telecom Cabling • For a third pair, white (tip) and blue (ring). • For larger numbers of wires, more complex schemes such as the 25-pair color code are used.

10. Telecom Cabling • Residential Color Code (USOC), uniform service order code.

11. Telecom Cabling • Green before Red, Black before Yellow • Christmas and Halloween.

12. Telecom Cabling • How would we wire 4 pair UTP (blue, orange, green, and brown) to a quad style jack?

13. Telecom Cabling • Answer: white/ blue to green, blue/white to red, white/orange to black, and orange/ white to yellow.

14. Telecom Cabling • STP cable (shielded twisted pair). • 4 pair cable with an overall foil shield and each pair is shielded. • Used in areas where interference can occur (e.g. a machine shop) or T1s.

15. Telecom Cabling • STP cable, notice it has a small metallic wire. • This small metallic wire is called the drain wire and is usually ground to the patch panel.

16. Telecom Cabling • Note that with shielded cable we must use a shielded jack and a shielded patch panel as well.

17. Telecom Cabling • In some instances we install a screened cable called ScTP, this also has a drain wire.

18. Telecom Cabling • 1- conductor • 2-insulation • 3-cable jacket or sheath

19. Telecom Cabling • Cable construction: • A typical cable is constructed with copper conductors which are covered with insulation and are then covered with a jacket or sheath with a rip-cord inside the jacket as well.

20. Telecom Cabling • How do you know what type of cable you have? • The cable jacket is labeled every 4 feet. • This is important information for the installer.

21. Telecom Cabling • Because cables installed in a building can be a source of toxic fumes and flame spread during a fire, the type of material used in the jacket and insulators is important.

22. Telecom Cabling • It is so important that it is regulated by several government agencies and we are required by law to install the correct cable type in the correct place. • Lets look at the types of cable jackets we use in our industry.

23. Telecom Cabling • There are essentially three areas into which we install our cables: • PLENUM CMP (P denotes plenum) • NON-PLENUM (general purpose) CM • RISER CMR (R denotes riser)

24. Telecom Cabling • WHAT IS A PLENUM? • Aseparate space provided for return air circulation for heating, ventilation, and air-conditioning • Typically provided in the space between the structural ceiling and a drop-down ceiling.

25. Telecom Cabling • A plenum may also be under a raised floor. In buildings with computer installations, the plenum space is often used to house connecting communication cables. • Because ordinary cable introduces a toxic hazard in the event of fire, special plenum cabling is required in plenum areas.

26. Telecom Cabling • Plenum cable is usually about 3 times more expensive than non-plenum cables. • This a huge consideration when installing cables.

27. Telecom Cabling • In the U.S., typical plenum cable sizes are American Wire Guage (AWG) sizes 22, 23 and 24. • Plenum cabling is often made of Teflon and is more expensive than ordinary cabling. • In the event of fire, its outer material is more resistant to flames and, when burning, produces less toxic smoke than ordinary cabling.

28. Telecom Cabling • Here we see cable designations: • The white cable indicates that it is a CAT 5 patch cord. • The yellow cable is type CMP and the pink cable is CM.

29. Telecom Cabling • RISER-used in vertical tray applications such as cable runs between floors through cable risers or in elevator shafts. • These spaces cannot be used for environmental air. • These cables must self extinguish and must also prevent the flame from traveling up the cable in a vertical burn test.

30. Telecom Cabling • Cables used in vertical riser shafts must have the CMR listing.

31. Telecom Cabling • Some high pair count cables (100 to 2400 pr.) may be PIC (plastic insulated cable)types. • This type of cable has a 25 pair color code with no tracers so it is very important to not let the pairs untwist.

32. Telecom Cabling • General Purpose -Will burn and partially self extinguish. • Not for use between build floors or in air plenum spaces. • Often these cables are used for workstation cables and patch cords.

33. Telecom Cabling • Can CMP cable be substituted with CMR cable for horizontal runs? • Can CMR cable be substituted with CMP for use in vertical riser shafts?