Engineering Documentation

Table Of Contents
Chapter 1 Wiring Regulations and Specifications
National Electric Code (NEC) Communications Requirements
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Fig. 1: Earth Grounding System.
National Electric Code (NEC) Communications
Requirements
The following topics are discussed in this section:
Smoke and Flame Characteristics [ 18]
Common Grounding for Communication Circuits [ 18]
Smoke and Flame Characteristics
The National Electrical Code (NEC) requires that communication and signaling cables
in a building shall be listed for both smoke and flame characteristics suitable for the
purpose.
Common Grounding for Communication Circuits
NEC Article 800 requires communications circuits to use a common ground. Use one
of the following methods:
Bond service grounds with No. 6 wire per NEC 250.
Isolate communications circuits on separate services with an HSTIE or Fiber Optic
Trunk Interface on each service.
NEC Article 800 covers communication wiring:
CMP Use in plenums.
CMR Use in risers.
CM General purpose.
CMX Residential and restricted commercial.