National Electrical Code ExplanationsBased on the 2017 NEC
National Electrical Code Tips: Article 830, Network-Powered Broadband Communications Systems Part 3
- The requirements for installation methods for systems within buildings are provided in Part V.
- You are limited as to what kinds of raceways you can use. But it's a BIG limit. For example, low-power cables can be run in any Chapter 3 raceway [830.110(A)(1)]. But you must install them per Chapter 3 requirements.
- In addition to the above example, low power cables can run in plenum communications raceways, riser communications raceways, and general-purpose communications raceways [830.110(A)(2)]. But you must select them per Table 800.154(B) and meet some other requirements.
- Raceway fill requirements of Chapters 3 and 9 don't apply to low-power or medium-power network-powered broadband communications cables [830.110(B)].
- Only certain types of cables can be in ducts specifically fabricated for environmental air. These are listed in 830.113(B).
- Only certain types of cables can be in spaces used for environmental air. These are listed in 830.113(C).
- Only certain types of cables can be listed in certain other applications. The types are listed by application in 830.113(D) through (I).
- Conductor separation requirements are listed in 830.133(A)(1). It's a detailed listing, and it applies to conductors in raceways, cable trays, boxes, enclosures, and cable routing assemblies.
- Network-powered broadband communications cable must be separated at least two inches from conductors of any electric light, power, Class 1, and/or non-power-limited fire alarm circuits [830.113(A)(2). Note this is not an exact spacing requirement. For example, suppose you have a large equipment cabinet where cables of these various types enter and are routed within the cabinet. You could route the Network-powered broadband communications cables along the front wall of the ceiling and the other cables along the back wall of the ceiling or in some other way use the width or depth of the cabinet for spacing. Nothing stops you from (greatly) exceeding that two inch minimum. Using the "opposite wall" method ensures you won't violate that minimum, and it will probably make maintenance easier while lowering installation costs.
- The permitted and nonpermitted applications of network-powered broadband cables are indicated in Table 830.154(A) [830.154].
The remainder of Article 830 is Part IV, Listing Requirements.
How the NEC is arranged
- The first four Chapters of the NEC apply to all installations.
- Article 90 precedes Chapter One, and establishes the authority of the NEC.
- Article 80 follows the body of the NEC; it exists as Annex H. It provides the requirements for administration.
- Chapters 5, 6, and 7 are the "special" chapters, covering special: occupancies, equipment, and conditions (in that order).
- Chapter 8 provides the requirements for communications systems.
- Chapter 9 provides tables.
- The appendices provide mostly reference information.
- Appendix D contains examples that every NEC user should study.
Try your NEC moxy:
- Do you know the difference between bonding and grounding? Hint: Look in the NEC, Article 100.
- Does the NEC refer to grounding incorrectly in any of its articles? Yes! So be careful to apply the Article 100 definitions. Don't ground where you should bond.
- When doing motor load calculations, which Article covers hermetic motors? Answer: While Article 440 covers the application of hermetic motors, it does so only by amending Article 430 because hermetic motors are a special case of motors. For motor load calculations, refer to Article 430.
- Does the NEC provide a voltage drop requirement? Yes! It does so in a special case, which is Article 648 Sensitive Electronic Equipment. But for general applications, it does not provide a requirement; it merely provides a recommendation in a couple of FPNs.
- Take our Code Quizzes.
Remember other applicable codes, rules, standards, and references:
- OSHA's electrical worker safety rules.
- IEEE standards.
- NETA standards.
- NFPA standards.
- International Codes (if applicable to the installation).
- State Codes (if the state has them).
- Local ordinances and permit requirements.
- Local fire codes.
- Manufacturer requirements or guidelines.
- Customer security requirements.
- Industry standards.
- Your company's own internal standards, practices, and procedures.
- Engineering drawing notes.
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