Installing Category Data Cables

Bending Category Cables
A proper category cable bend radius, 4 times the cable diameter Example of a category cable bend greater than 90 degrees
Maintain a minimum bend radius of 4 times the cable diameter (4-pair cables). Never exceed a 90 degree bend! This causes disruption in conductor and cable integrity.
Cable Ties
How to apply category cable ties without pinching Wrong way to tie category cables, overtightening
Apply cable ties loosely and at random intervals. Don't overtighten cable ties, as pinching or crushing will result in attenuation or impedance.
Twisting Cable
Jacket twisting for category cables Example of overtwisting category cable jackets
Try to minimize the amount of jacket twisting If the cable is overtwisted it can lead to torn jackets.
Staple Guns Cable Termination
Don't use staples to position electrical cables. Twist cables to within .5 inches of the termination.

DO NOT use staple guns to position cables
Use appropriate methods for dressing and securing cables:

  • Cable Ties
  • Cable Support Bar
  • Wire Management Panels
  • Releasable Velcro Straps
Make sure every twisted pair cable maintains its pair twisting to within 1/2" or less of the point of termination on the connecting hardware. Any untwisting of pairs greater than this will adversely affect the performance of the cable and reduce its ability to transmit at full, effective speeds.

Cable Runs

  • Plan out your installation so that you do not run cable further than 90m (295').
  • Never run data cables in the same conduit as electrical wiring.
  • Home run cable where possible to maximize data transmission.
  • For Category 5 Patch cables -- ANSI/TIA/EIA 568A allows for a maximum patch cable length of 6m (20') in the wiring closet and 3m (10') at the workstation outlet. If either of these lengths is exceeded, your horizontal cable run must be reduced by the excess amount.
  • When pulling cable, avoid kinking and tugging. Constant tension should be used when pulling cable into place. EIA/TIA-568A specifies a 25 pound maximum pulling tension for category cable installation.

Miscellaneous Tips

  • Many networks that run on UTP cable use only two of the four pair of wires. To prevent crosstalk do not use the second unused pair for voice or other data application.
  • When routing cables through walls and ceilings, always keep data cable as far as possible from sources of EMI (electromagnetic interference) and RFI (radio frequency interference), such as fluorescent lights, electric panels, light dimmers and electrical motors.
  • Avoid heat and moisture. High temperature and moist locations may cause attenuation problems.
  • Patch cables are intended to be flexed and moved, so stranded conductor patch cords are recommended because of their flexibility over solid conductor.

Basic Topologies

Star Topology

Example of Star Topology

Utilizes a central point of control. Each station or device in the telectommunications system communicates point to point wiring to this central link. In most situations, address recognition is the responsibility of via point to point wiring to this central link. In most situations address recognition is the responsibility of central control point which then directs the information to the cabling path of the device associated with that address. A star topology is considered the easiest to design and install since each station's cabling is run directly out from the central location to the appropriate work area. It is also adaptable to other topologies.

Ring Topology

Example of Ring Topology

Structured with stations cabled together in a logical circle. Information travels in one direction passing through each station and only stopping at the addressed station. Only one station can transmit on the ring at any one time. Stations take turns gaining access to the ring via polling or by passing an access token from one to another.

Bus Topology

Example of Bus Topology

Has all the devices attached to a linear transmission media. When a station transmits, the signal travels in both directions. Signals traveling along the bus are made available to all stations. Each station checks the intended address of the signal and ignores all information not addressed to its location.