Kingston Technology KNE8TX/WG User Manual

Page of 27
Appendix B    Cabling Guidelines 
13 
KNExTX/WG User’s Guide  - Rev. A00                Kingston Technology Company 
Rating Codes 
 
UTP cables meet different UL-NEC requirements based on cable-jacket 
quality.  Below is an explanation of the rating codes for each cable type. 
 
UL – The National Electrical Code (NEC), published by the National Fire 
Protection Association (NFPA), details advisory safety considerations for 
electrical wiring.  NEC Article 800 Communications Cables are manufactured 
to meet these different cable types. 
 
1.  CMP – Cables meeting type CMP requirements are suitable for 
installation in ducts and plenums without the use of conduit.  These cables 
are designed for fire resistance and low-smoke producing characteristics. 
2.  CMR – Riser type cables are engineered to prevent the spread of fire from 
floor to floor and are suitable for vertical shaft applications. 
3.  CM – Cables for general building wiring.  CM cables are used in areas 
other than plenums and risers.  These cables are resistant to the spread of 
fire and pass the UL 1581Vertical Tray Flame Test. 
4.  MP, MPR &  MPP – Within Article 800, the Multi-purpose Cables 
Category, allows conditional substitutions between different cable types & 
are restricted by number, AWG size and stranding of the cable 
conductors. 
Terms You Should Be Familiar With 
1.  BACKBONE WIRING – The physical/electrical interconnections 
between telecommunications closets and equipment rooms. 
2.  COMPLIANCE – A wiring device that meets all characteristics of a 
standard is said to be in compliance with that standard. 
3.  TWISTED PAIR (UTP) – Two insulated copper wires twisted around 
each other to reduce interference from one wire to the other.  The twists 
are varied in length to reduce the potential for signal interference between 
pairs.  Several sets of twisted pair wires may be enclosed in a single cable.