Low Voltage Cabling Terms

What is Low Voltage Cabling? People use lots of different terms; VDV (for Voice, Data, & Video), Data/Voice, Voice/Data, Low Voltage, Limited Energy, Teledata, Tel/Data, Datacom, Premises Cabling, but most call it “Structured Cabling” after the “TIA 568″ Standard. It’s the infrastructure for telephone and LAN connections in most commercial installations and even in some modern homes. It’s also used for fire alarms, building management, audio and video.

Here are some common cabling terms:

AWG (American Wire Gage): A standard method to measure wire. The numbering system works backwards, thicker/heavier wire has a lower the number. (Example; a 24AWG wire is thicker/heavier than a 26AWG wire)

Bandwidth: The range of frequencies used to describe the potential capacity of the device or system. The numerical value is expressed in Hz (Hertz) or Megahertz (MHz) and used for both copper and fiber.

CAT3: Cable has a maximum frequency range of 16 MHz. It was typically used for voice and low speed networks. (Rarely used anymore)

CAT5: Cable was used for networks and multi-line phone systems. It had a maximum frequency of 100 MHz and could transmit up to 10/100Mbps. Category 5 (CAT5) was defined in ANSI/TIA/EIA 568A, but is not used with ANSI/TIA/EIA 568B. (Rarely used anymore)

CAT5e: Cable is used for networks and multi-line phone systems. It has a maximum frequency of 100 MHz and can transmit up to 10/100/1000Mbps. Category 5 Enhanced (CAT5e) will work with ANSI/TIA/EIA 568A and ANSI/TIA/EIA 568B. (Most Common Cabling used today)

CAT6: Cable is used for networks and multi-line phone systems. It has a maximum frequency of 250 MHz and can transmit up to 10/100/1000Mbps. (quickly becoming the standard go to cabling)

CAT6A: Cable is used for networks, it has a maximum frequency of 500 MHz and can transmit up to 10/100/1000Mbps and 10Gbps. (used for stringent high bandwidth needs)

Coaxial: Cable contains a center core conductor, and a second conductor wrapped around it. The second conductor can be made from different types of braided conductors (typically au – gold, cu – copper, and al – aluminum) or a metal foil. The outer wire is typically the ground.

DB9 (RS-488): Connector is a 9-Pin serial connection used on most laptop and desktop computers, as well as token ring connections. DB connectors are gender specific (Male/Female), so when ordering or connecting any DB connector, make sure you have the correct gender on the cable.

DB15: Gender specific connector (Male/Female) with 15 pins used for connecting to Mac Monitors or PC Joysticks.

HD15 (VGA): Gender specific connector (Male/Female) with 15 pins (HD15/VGA) used for connecting PCs to PC Monitors.

DB25 (RS-232): connector is a 25-Pin connection used on most desktop computers to connect serial or parallel ports together. DB connectors are gender specific (Male/Female).

Half-Duplex: – In data communications, Duplex transmissions are bi-directional. Half-Duplex allows transmission in both directions, however only one at a time.

Full Duplex: In data communications, Duplex transmissions are bi-directional. Full-Duplex allows transmission in both directions at the same time. (Full-Duplex allows more information to be transferred)

Drain Wire: An uninsulated wire inside a shielded cable that runs the length of the cable and acts as a grounding point for the shield.

Ethernet: is a broadcast network where when one station transmits a message, all stations will “hear” the message, but only the addressed station will “open” the message. Ethernet has become a standard for LANs and has gone from 10Mbps to 1000Mbps over the last 20 years.

F-Connector: are used on coaxial cable, typically used with Cable TV, VCR’s, Security Systems, Satellite Systems and other Video applications. The most common cables used are RG58, RG59 and RG6. The connectors come either in a single or 2-piece set. They can either be crimped, soldered, or twisted on.

Fiber: Is a thin strand of glass or plastic optical fiber that transmits light impulses.

Frequency: Is the number of cycles or waves per second, expressed in Hertz, (Hz). In structured cabling the information carrying capacity (bandwidth) is measured in Hz.

Gender Changer: A small adapter that changes the gender of a connector.

Gigabit (Gb): The transmission speed of 1 billion bits of information. Transmission speeds are measured in bits per second, therefore a Gigabit is 1 billion bits of information per second. More commonly known as Gigabit, Gb, or 1000Mbps.

Hertz (Hz): A unit used in the measurement of frequency equal to one cycle per second. Frequency is generally measured in Kilohertz (KHz) or Megahertz (Mhz).

Ethernet Switch: Is a network device that is used as a central location in a wired LAN. The Ethernet Switch controls, manages, and directs information through the segment of the network connected to it.

IEEE: (Institute of Electrical and Electronics Engineers): Has set most of the LAN standards through the 802 series.

Impedance: Is a measure of the total opposition to current flow in an alternating current circuit, made up of two components. With higher speed and bandwidth networks, the impedance of the cable plant as a whole, can affect the networks performance.

Impact Tool: Have a spring-loaded head that when used will punch down on the conductor and into a 66/110 block.

Latency: Is the amount of delay a signal has when going through a network or a part of a network. The Total Latency is calculated by adding together all the time delays through each device and media.

MAC Address: Every network device (network interface card, router, etc.) has its own unique address. A computer without a NIC card does not have an address. The IEEE assigns each address and prevents duplicate addresses from happening.

Megabit Per Second (Mbps): Is a measurement of the transmission speed of a piece of equipment or network equal to 1-million bits per second.

Megahertz (MHz): Is a unit of frequency measurement equal to 1-million Hz or cycles per second. Megahertz is one measurement of bandwidth, or information carrying capacity of a network, cable or connectors. Generally, Hz should not be confused with Bps (bits per second).

Network Interface Card (NIC): The network interface card is the point where the computer is connected to the local area network. The NIC is matched to the type and speed of the network, ie; 10/100/1000Mbps Ethernet.

Noise: Is a random and/or persistent induction of unwanted electrical or radio frequency signals onto a cable which interferes with and/or degrades the quality of the signal.

Ohm: Is a unit of resistance. The measurement of the opposition to the flow of direct current is resistance. One volt will cause 1 ampere to flow through 1 Ohm of resistance.

Ohms Law: Is the mathematical relationship between Ohms(R), volts(V) and Amps(I). Technically it states that current (I) is directly proportionate to voltage and inversely proportionate to resistance. The mathematical equations are: V = I x R or I = V/R or R = V/I.

Plenum Cable: In some buildings, the entire space above the drop ceiling is used as a return air pathway instead of a set of ducts. Therefore, air circulated within that space gets distributed throughout the floor, or the building. If a cable located in an open-air plenum has a PVC jacket and catches fire, the toxic fumes would spread throughout the entire floor via the open plenum, thereby suffocating or at least impairing people’s ability to get out of the building. To overcome this, some cables are coated with Teflon to prevent the spread of flame and toxic fumes. Individual states regulate what types of cables are acceptable as a minimum standard. Extreme care must be taken by the installer and designer to ensure the proper cables are specified and installed.

Plenum Cable: Plenum rated cable has been specifically engineered to be placed in the plenum air space above a suspended ceiling. In the event of a fire, the components of the jacket and conductor insulation will not give off toxic fumes and are slower to burn. A plenum rated cable will have on it one or both of the following markings: FT-6 or CMP. Both of these markings are recognized in the United States and Canada.

Polyvinylchloride PVC: A thermoplastic flame and water retardant material commonly used in the construction of communications and other building cables. Although flame retardant, PVC gives off toxic fumes when burned. For this reason, many city, county, or state codes do not allow PVC based cables to be installed in return air plenums or ducts in case of fire, instead Plenum rated cable is used.

RG-58: Is a 50 Ohm coaxial cable used with Cable TV and BNC environments.

RG-59: Is a 75 Ohm coaxial cable used with Cable TV. It is the old standard for home installations, now installers are using the new RG6 cable.

RG-6: Is a 75 Ohm coaxial cable used with Cable TV, Satellite and High Definition TV. It is also becoming the minimal standard for home installations due to its’ full frequency capacity.

RG-6 Quad Shield: Is a 75 Ohm coaxial cable used with Cable TV, Satellite and High Definition TV. It is also becoming the minimal standard for home installations due to its’ full frequency capacity. This cable is quad shielded which will help prevent line interference and noise.

RG-62: Is a 93 Ohm coaxial cable.

SC Connector: Is a type of fiber optic connector that uses a push to snap on/push to snap off connector. The SC connector can be used with both multi-mode and single-mode fiber.

ST Connector: Is a fiber optic connector that uses twist-on/twist-off.

STP: is Shielded Twisted Pair.

UTP: is Unshielded Twisted Pair.

Twisted Pair Cable: is a cable consisting of individual conductors twisted in pairs around each other. The purpose of twisting the conductors around each other is to reduce the effects of crosstalk.

TIA-568B: Is the standard which governs the installation of cabling and components in a commercial building. The full name is ANSI/TIA/EIA 568B, although it more commonly goes by 568B.

TIA-569: Is the standards document published by the TIA governing the design and installation of pathways and spaces for cable used in those pathways and spaces as they relate commercial buildings. The full name is ANSI/TIA/EIA 568A, although it more commonly goes by 569A.

EIA/TIA 570: For residential cabling.

EIA/TIA 606: cabling system administration (documentation), ISO/IEC 14763-1

EIA/TIA 607: Grounding and bonding

Standards are not code! They are voluntary interoperability specifications. However every installation must be compliant to local building codes for safety!

NEC (National Electrical Code): written by NFPA (National Fire Protection Assn.) this

code sets standards for fire protection for construction and is a legal requirement in most cities.

Wavelength: Is the distance between a point on one wave to the similar point on the next wave. The number of times this happens over a given period of time, (normally 1 second) is the frequency. Frequency is measured in Hertz.

Telecom Room: The location of the connection between horizontal cabling to the backbone.

Main Distribution Frame (MDF): Is an old telco term for the location of the main electronics in a building. Today, we call it the Equipment Room.

Intermediate Distribution Frame (MDF): Is a termination/equipment location in between the MDF and a specific endpoint. (usually installed because of distance between an endpoint and MDF exceeds maximum allowed distances by equipment)

Jack/Outlet: The jack on the wall which is connected to a desktop computer or phone by a patch cord

RJ-45: Is the popular name of the modular 8-Pin connector used in structured cabling systems.

Patch Panel: Is a rack or box where cables are terminated – usually in 110 punch downs and interconnected with patch cords.

Horizontal Cabling: Is the connection from the equipment room to the jack/outlet

Backbone Cabling: Is the cabling that connects all the IDF’s to the MDF

10Base-T: 10 Mbps

100Base-TX: 100 Mbps

1000Base-T: Gigabit (Gb)

Power over Ethernet (PoE): The IEEE 802.3 Ethernet committee added provisions for powering devices off the spare pairs in a 4-pair UTP cable.

ECS is a Certified, Licensed, Bonded Low Voltage Cabling Contractor located in Seattle, WA & Portland, OR.

ECS provides local technicians for on-site work installing and servicing a variety of voice/data equipment, ie; Low Voltage Cabling, CAT5e/CAT6, Fiber Optic, IP Office Telephone Systems, Voicemail, Telephones, Firewalls, Ethernet Switches, Circuit Extensions, Wireless Networking, Video Surveillance, Point of Sale, Overhead Paging, Avaya Aura Servers, Gateways, etc. 

ECS provides services in Washington & Oregon, primarily in the greater Seattle & Portland areas.

Comments are closed.