Article 800 covers circuits that extend voice, audio, video, interactive services, and external wiring for fire alarms and burglar alarms from the communications utility to the customer's communications equipment (Grave. 1). It does not apply to communication tool equipment that is controlled solely by the communication tool [90.2(B)(4)]. Section 90.3 informs us that art. The 800 is not subject to the requirements of NEC Chapters 1 through 7 unless specifically stated in those chapters.
Choose "W" for build quality
Install communications equipment and cables in a neat and professional [800.24] manner, and do not allow cables to block access to equipment or [800.21] the ceiling.
Support exposed cables with brackets that attach to framing members, secure cables with straps, staples, hangers, cable ties, or similar fasteners [800.24]. Install them in a way that does not damage the cable.
You can support the rails and cables with independent support wires attached to the suspended ceiling in accordance with the 300.11 standard. Do not use ceiling support wires or ceiling net [300.11] directly.
Do not tape, tape or attach communication wires or cables to the treadmill as a support measure. [800.133(B)].
Communication equipment must be replaced [800.170]. Install it according to the manufacturer's instructions in accordance with 110.3(B) [800.18]. Ancillary equipment shall not be disclosed, but NFPA 90A-2009 includes heat release and smoke emission requirements for "cable ties" in Chapters 4.3.11.2.6.5 (enclosures) and 4.3.11.5.5.6 (enclosures with raised floors) [800.24 Note 2].
Stop the spread of fire
These three articles of Krav 800 limit the spread of fire or combustion products:
•Label cables for future use. If some cables will not be terminated because they are for future use, each cable must be labeled with an environmental label [800.25]. This distinguishes them from abandoned cables.
•Remove abandoned cables. If the cable is not terminated and is not intended for future use, remove the accessible part [800.2]. The cables installed in the hidden treadmills are inaccessible, so they do not need to be removed.
•Use fire extinguishing measures. Fireproof openings in walls, floors and fireproof ceilings for electrical equipment. Use fireproof materials specified for specific types of wiring methods and building construction. Use AHJ-approved firefighting methods to maintain the fire resistance rating of the fire unit [800.26] as shown inGrave. 2.
Cables entering buildings
Underground communication cables shall not be replaced in wet locations [800.47].
Overhead (antenna) communication cables must be at least 8 feet from all points on the roofs they pass over [800.44]. This does not apply to outbuildings such as garages. You can reduce that clearance to 18 inches, if not more
6-foot overhead (antenna) wires pass no more than 4 feet from the roof and terminate at the treadmill mast or other approved support.
Unlisted communication cables may be installed in building spaces other than risers, ducts, or equalization spaces as described in 300.22(C) if the length of the building cable from the point of entry does not exceed 50 feet and the cable terminates in an enclosure or primary protector [800.48]. There is a catch though. For each communication circuit, install the specified primary protection as close as possible to the [800.90(B)] entry point. Therefore, unlisted communications cables cannot enter a building if it is possible to place the primary containment closer than 50 feet from the point of entry.
In installations where the communication cable enters a building, the metal jacket of the cable may be grounded in accordance with 800.100 or may be terminated by an isolation splice or equivalent device as close as possible to the point of entry.
Earthing methods
Connect and ground the head protector and the metal part of the cable sheaths in accordance with 800.100 (A) to (D). What does it mean? The two simplest requirements are:
(C) Complies with 250.70 when connected to ground electrodes.
(D) If a separate ground electrode (eg, a ground rod) is installed for the communication system, it must be connected to the building ground electrode system with a minimum of 6 AWG wire.
Section 800.100(A) contains requirements for a bonding or grounding wire:
(1)Insulation. It must be replaced.
(2)Material. Copper or other conductive material resistant to corrosion.
(3)Size. At least 14 AWG with a current-carrying capacity not less than the grounded metal jacket or shielded conductor of the communications cable. It need not be larger than 6 AWG.
(4)Length. As short as possible. In one- and two-family houses, the equipotential bonding or ground electrode wire must not be longer than 20 feet.
(5)ran straight ahead. Run as straight as possible.
(6)Physical protection. The equipotential bonding conductor and the earth electrode conductor must not be exposed to physical damage. When installing in a metal raceway, connect each end of the raceway to a wire in the raceway, or connect the ends to the same terminal or electrode that the jumper wire or ground electrode wire is connected to.
There is an exception for 800.100(A)(4). If the connection wire or ground electrode wire is larger than
20 feet long for single- and two-family dwellings, then install a separate ground rod at least 5 feet long [800.100(B)(3)(2)] with fittings appropriate for the [800.100(C)] application. Connect this to the ground electrode system with a minimum of 6AWG [800.100(D)] wire.
Section 800.100(B) provides ground electrode requirements for three types of applications:
Inter-Bundling Termination Structure (IBT). The connecting lead for primary protection and the metal sheath of the communication cable must terminate at the IBT as required by 250.94 (Grave. 3).
Structure without IBT. The equipotential bonding cable or earth electrode cable must be terminated at the nearest available:
(1) Building/structure grounding electrode system [250.50].
(2) Internal metal water piping system within 5 feet of point of entry [250.52(A)(1)].
(3) Available funds outside the building pursuant to 250.94 Ex.
(4) Non-flexible metal service track.
(5) Housing for service equipment.
(6) Earth electrode wire or metal housing for the mains earth electrode wire.
(7) Ground electrode wire or ground electrode in a remote building/structure disconnect [250.32].
Structure without IBT or earthing measures. The earth electrode wire must be connected to:
(1) Any single ground electrode described in 250.52(A)(1), (A)(2), (A)(3), or (A)(4).
(2) Any single ground electrode described in 250.52(A)(6) and (A)(7) or to a ground rod not less than 5 feet long and ½ inch in diameter, located at least 6 feet from the electrodes in another system.
Cables in buildings
Communication cables installed in buildings must be replaced unless the length of the cable from the point of entry does not exceed 50 feet in accordance with 800.48. Communication cables may be installed in any Chapter 3 conduit as required by Chapter 3 [800.110]. The 300.17 race fill limitations do not apply to communication cables installed on the treadmill. Alternatively, you may install cables in the specified communication path if you do so in accordance with 362.24 through 362.56 (provisions for ENT).
If you are installing communications cables in prefab ducts used for ambient air, you can choose from five acceptable cable types. You can use up to 4 feet of CMP cable with no treadmill limitations. To use a longer CMP series or to use a CMR, CMG, CM or CMX, the treadmill must be 300.22(B) compliant. In attics used for ambient air, the requirements are similar but somewhat more complex [800.113(B)].
Communication cables may be in the same conduit, cable tray, cable management device or enclosure as the conductors of any of the following [800.133]:
• Fiber optic cables in accordance with parts I and IV in art. 770.
• Coaxial cables in accordance with parts I and IV of art. 820.
• Class 2 and Class 3 circuits in accordance with parts I and III of Art. 725.
• Fire alarm circuits with limited power according to parts I and III of art. 760.
Communication cables can be in the same cable as class 2 or 3 cables if the cables meet the requirements in art. 800 [725.139(D)(1)].
Do it right
In order to apply art. 800, start by noting:
• How precise is the entry point.
• How far, in terms of cable runs, the primary containment is (or will be) from the point of entry.
• What other ground rods exist and whether they are connected to each other.
Documenting these few facts right from the start will help you avoid the most common communication cable system errors.
Holt is the owner of Mike Holt Enterprises, Inc. in Leesburg, Florida. He can be contacted at the addresswww.mikeholt.com.