Post on 30-Mar-2015
Cable Management
• DATA CABLE IS SUSCEPTIBLE TO DAMAGE
• INSTALLING CAT5 CABLE DOES NOT GUARANTEE CAT5
PERFORMANCE
• HOW CABLE IS INSTALLED, NOT ONLY WHAT TYPE OF
CABLE IS INSTALLED
• IF CABLE NOT INSTALLED PROPERLY
PROBLEMS WITH
– ATTENUATION
– NEXT
– PS NEXT
– FEXT
– PS FEXT
• ANSI/TIA/EIA-568-A 10.6.3.2 SPECIFIES
– APPROPRIATE CABLE MANAGEMENT MUST BE USED TO
ELIMINATE
• CABLE STRESS • UNTWISTING OF PAIRS
• CABLE CINCHING • TWISTING OF CABLE
– CABLE MUST ALSO BE INSTALLED TO MANUFACTURES
SPECIFICATIONS
SURFACE RACEWAY
• COVERED BY EIA/TIA-569 SECT.4.7
• LISTED IN FOUR (4) SUBGROUPS :– SURFACE RACEWAY
– RECESSED RACEWAY
– MOLDING RACEWAY
– MULTICHANNEL RACEWAY
• AGAIN CABLE MUST
– NOT BE PUT UNDER STRAIN
– MAINTAIN A MINIMUM BEND RADIUS
– BE SUPPORTED (REGARDLESS OF TYPE)
– BE IN A SUITABLE ENVIRONMENT
– PROTECTED FROM EMI (e.g. RFI) (COPPER ONLY)
(BOTH COPPER & FIBRE)
DON’TS
• NEVER PULL CABLE DIRECTLY ACROSS SUSPENDED CEILING
TILE OR ACROSS FLORESCENT LIGHT BOXES (EMI)
• CABLE SHOULD NOT BE TIED TO CEILING GRIDWORK WIRES
WHAT NOT TO DO
MANAGEMENT TYPES
• THERE ARE VARIOUS DIFFERENT TYPES OF CABLE MANAGEMENT EACH GIVING DIFFERENT DEGREES AND TYPES OF PROTECTION
CABLE TIES
• USED TO SECURE CABLE TO TRAYS, TRUNKING ETC.
• NYLON, POLYPROPYLENE
• RELEASABLE, NON-RELEASABLE
• RIBBED INNER SURFACE TO SECURE CABLE
“J” HOOK BENEFITS
• DESIGNED FOR “HIGH PERFORMANCE” CABLE
• USED SPARINGLY OVER SHORT RUNS
• LIMITS THE NEED FOR CABLE TIES
“J” HOOKS SHOULD NOT BE USED AS A REPLACEMENT FOR CABLE TRAY
D-RINGS
• AS WITH J-HOOKS
• FOR SMALL BUNDLES OF
CABLE
• USED SPARINGLY OVER
SHORT RUNS
A
B
• THE J-HOOKS ARE NOT ADEQUATE SUPPORT HERE
• THE CABLE IS UNDER STRESS AT POINTS A & B
CABLE LADDER
• GALVANISED STEEL OR PVC
• CABLE SECURED AT RUNGS
CABLE LADDER
• WITH LARGE BUNDLES CABLE UNDER PRESSURE AT RUNGS BECAUSE ITS WEIGHT IS NOT DISTRIBUTED ALONG A RUN
AS WITH CABLE LADDERS CABLE WEIGHT NOT EVENLY DISTRIBUTED. BASKET IS CHEAPER AND EASIER TO INSTALL THAN LADDER
CABLE BASKETS
SNAKE TRAY
• SIMILAR TO CABLE BASKET
• FLEXIBLE
• EASIER TO INSTALL?
• FLEXIBLE
CABLE TRAYS
• GALVANISED STEEL OR PVC
• VARIOUS DIMENSIONS
• MAY BE RESIZED WITH
HACKSAW
• ANGULAR INSERTS AVAILABLE
CABLE TRAYS
• PERFORATED BOTTOM
• HORIZONTAL & BACKBONE
• FLEXIBLE
• EASY ACCESS TO CABLE
• CURVED TRAYS
• SUPPORTS WEIGHT OF CABLE
ALONG WHOLE RUN
CONDUIT
• COMPLETELY ENCLOSED
• NO REMOVABLE LID
• GALVANISED STEEL PVC
• ACCESS TO CABLE LIMITED
CONDUIT
• EMI PROTECTION
• OUTLET DENSITIES LOW
• MEDIUM TO LONG TERM
• NEAT & AESTHETIC
TRUNKING
• SIMILAR TO CABLE TRAY BUT
• REMOVABLE LID (BETTER PROTECTION) (EMI & RODENT)
TRUNKING
• MORE DIFFICULT TO CUT (LID)
• NEATER
RACEWAYS
• SIMILAR TO TRUNKING
• VISUALLY PLEASING
• EASILY MODIFIED
• POWER AND DATA CABLING
POWER AND DATA SEPARATION
MIN BEND RADIUS
A
• DROPOUT PIECE ENSURES MIN BEND RADIUS IS MAINTAINED
• PRESSURE AT RUNG A IS ALLEVIATED
CABLE TRAY ASSEMBLIES
What is EMI?
• ELECTRO MAGNETIC INTERFERENCE– DESCRIBES ALL KINDS OF ELECTRICAL AND MAGNETIC
INTERFERENCE
• EMI IS A FIELD THAT EMANATES FROM ‘LIVE’ CONDUCTORS
– CAN TRAVEL LARGE DISTANCES AND INTERFERE WITH OTHER CONDUCTORS
• RFI (RADIO FREQUENCY INTERFERENCE)– 98FM CAN INTERFERE WITH CONDUCTORS
Sources of EMI
• SOME ‘LIVE’ CONDUCTORS CAN CAUSE MORE
INTERFERENCE THAN OTHERS
– DEPENDS ON SEVERAL FACTORS, SUCH AS THE AMOUNT OF
CURRENT THEY ARE CARRYING AND THE AMOUNT OF SCREENING
AROUND THE CONDUCTOR
• FLUORESCENT LIGHTING, SUBSTATIONS, MOTORS, SWITCH
MODE POWER SUPPLIES
Vulnerability
• SOME CONDUCTORS CAN PICK UP INTERFERENCE MORE EASILY THAN OTHERS
– UTP IS PARTICULARLY VULNERABLE TO PICKING UP EMI
– SCREENED CONDUCTORS OR CONDUCTORS IN EARTHED ENCLOSURES ARE LESS VULNERABLE BUT HAVE TO BE CAREFUL
– FIBRE IS IMMUNE TO EMI
EN 50174
• MAKES THE FOLLOWING RECOMMENDATIONS
En 50174
• EUROPEAN STANDARD SUBMITTED TO CENELEC
• THREE PARTS– SPECIFICATION– IMPLEMENTATION – OPERATIONS
OF INFORMATION TECHNOLOGY CABLING,BOTH COPPER & FIBRE}
• EMI PERFORMANCE DIFFERS WITH THE DIFFERENT TRAY TYPES
• THE BUNDLE HEIGHT INTO THE CABLE TRAY SHALL BE LOWER THAN THE SIDE WALLS AS ILLUSTRATED ABOVE
• OVERLAPPING LIDS PROVIDE MORE PROTECTION
• DEEP CONDUITS ARE PREFERRED
CABLE SUPPORT
• PROPER CAT 5 PERFORMANCE WILL ONLY BE ACHIEVED WITH
CAREFUL CABLE INSTALLATION AND ADEQUATE SUPPORT
• MAKE SURE “YOUR” INSTALLATIONS ARE NOT PART OF THE 80 %
THAT WILL NOT SUPPORT TRANSMISSION IN THE FUTURE OF 100
Mbps AND BEYOND