TIA Expands TIA/EIA-570-A's Scope

Just last month I informed you of the Telecommunications Industry Association’s (TIA’s) efforts to develop a specification for Building Automation Systems (BAS) for commercial buildings. This soon-to-be-published specification represents a significant departure for TIA-TR 42 in addressing cabling and system requirements outside their area of expertise of voice, data and video (VDV). This departure has been extended beyond commercial buildings into residential cabling with the approval of two addenda to TIA/EIA-570-A Residential Telecommunications Cabling Standard and the balloting of a third.

The two approved addenda are:

• TIA/EIA-570-A-1 Security and Alarm Cabling for Residences

• TIA/EIA-570-A-3 Whole-Home Audio for Residences

The third addendum is TIA/EIA-570-A-2 Control Cabling for Residences.

The main objective of all three addenda is to recognize the importance of all three systems in addressing the needs of a structured residential cabling system and the importance of installing these systems when the house is built. Unlike the BAS specification, though, these three addenda do not try to force these systems onto Category 5e cabling but recognize their benefits to other cables.

TIA/EIA-570-A-1 Security and Alarm Cabling for Residences specifically addresses both the NFPA 70-1999 National Electrical Code and NFPA 72-1999 National Fire Alarm Code requirements. Some of the more specific guidelines stated in this addenda are provided below.

• A smoke detector should be installed outside each sleeping area and on each additional floor, including basements.

• Heat detectors are recommended in kitchens, attics and garages.

• For multi-tenant residences, suitable controlled access needs to be provided for common areas.

• Certified alarm and security professionals should be consulted for planning and installation of systems.

• Alarm and security cables running parallel to AC power cables should be separated by 12 inches and, if they do cross, they should cross at right angles.

• The system should use an RJ-31X to give priority to the alarm system on the dial-up telephone line.

• The use of FPL listed cable for single-family residences and either FPLR (riser) or FPLP (plenum) for multi-family dwellings for alarm systems. All alarm cables should be solid-copper wire with a minimum gauge of 18 AWG.

• The use of CL2 listed cable for single-family residences and either CL2R (riser) or CL2P (plenum) for multi-family dwellings for security systems. Security cables may be stranded or solid, typically 18 or 22 AWG.

• All security cabling should be home run to each detector or sensor to the security panel, except for smoke detectors.

TIA/EIA-570-A-3 Whole-Home Audio for Residences provides more guidelines than the previous addendum, especially for planning and cable requirements. Listed below are some highlights.

• For standard volume controls (impedance-matching analog), the best practice is to limit the number of zones to eight.

• As a minimum, paired speakers shall be installed in each zone or room.

• Speakers should be located in a room/zone to provide stereo left and right when facing the main feature in the room, on the long wall of a room or when facing the typical sitting location in the room.

• The best speaker location should be half the distance from the main feature to the opposite wall on the left and right.

• Speakers should have a minimum clearance of 24 inches from a wall/ceiling or wall/wall interface.

• Three types of audio distribution cabling are identified.

—Amplifier to distribution device.

—Distribution device to volume control.

—Volume control to speakers.

• Six conductors of speaker wire and one Category 5e cable shall be run from the outlet at the amplifier to the distribution device.

• Four conductors of speaker wire and one Category 5e cable shall be run from the distribution device to the volume control for each zone.

• Two conductors of speaker wire and one Category 5e cable shall be run from the volume control to each speaker.TIA/EIA-570-A-2 Control Cabling for Residences is yet to be approved, but takes a similar approach as the security and alarm addendum. This draft references the Consumer Electronics Association (CEA)-established ratings for lighting control, climate control and whole-home automation.

The TIA recognizes that other cabling and network systems exist besides VDV, but it still realizes that it is not the expert and references the applicable long-standing industry documents. However, based on market studies of the residential cabling industry, the predominant driver for structured residential cabling systems is the need for computer networking and high-speed Internet access. EC

BEAM is director of systems marketing at AMP NETCONNECT Systems. He can be reached at 336.727.5784 or tebeam@tycoelectronics.com.

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