A Guide to Ethernet Cable Categories
Evolution of Category Cables
The evolution of category cables has been driven by industry needs to support the transmission of sensitive data signals over increasing distances and at greater speeds for system operations. From somewhat humble beginnings, category cables were first designed to support telephone and fire alarm applications and have now progressed to extensive use in large data centers and advanced system networks.
Setting the category cabling standards for Industry, standard ANSI TIA/EIA-568 was developed through the joint efforts of the Telecommunications Industry Association (TIA) and Electronic Industries Alliance (EIA) in the United States. In Europe a similar standard ISO/IEC 11801 was created to define cable categories. In addition to detailing complete system operating functionalities, these standards define the hierarchy for category type cables and the various electrical parameter requirements, and specify cable pin and pair assignments. With the development of emerging new technologies there is an abundance of related industry standards driven by specific global regions which have proliferated from TIA/EIA and ISO/IEC documents.
WHAT ARE THE ETHERNET CABLE CATEGORIES
The chart to the left shows what the different categories of ethernet mean, with the category cable hierarchy in descending order.
While the highest level indicates optimum performance, the majority of today’s application requirements can be satisfied with Category 5e cables. Category 5e offers speeds of up to 1000 Mbps and bandwidth of 100 MHz. However, to prepare for the anticipated system needs of tomorrow, designers and project managers will consider “future proofing” their projects by using higher category level cables which are especially important in applications where precision signals must be transmitted at faster speeds. While Category 8, the highest category of ethernet cable, is at the top of the hierarchy offering speeds of up to 40 Gbps and 2000 MHz bandwidth, there is a 30m length limitation to achieve these attributes. Category 7a at 10,000 Mbps and 1000 MHz at 100 meter maximum lengths follow, but due to its inherent high cost along with Category 8, the debate for potential substitution with fiberoptic cables becomes a valid point of discussion amongst installers, system designers, and others. For most applications being installed today and designed for tomorrow, Category 7 would be the ideal choice because it offers speeds of up to 10,000 Mbps, a bandwidth of 600 MHz, and lengths of up to 100 meters at a competitive cost.
In addition to moving forward with electrical parameter enhancements, category cables themselves had to become increasingly more suitable to support industry trends and the challenges presented from the surrounding industrial environment. Improvements to flexibility, and the development of lighter cable designs enabled greater cost savings to the contractor through easy handling and routing resulting in quicker installations.
There are factors that must be taken into consideration when cables are installed in an uncontrolled environment. Cables must endure the unforgiving environmental conditions present inside the factory – commercial and industrial infrastructure.
Factory conditions can include extreme temperature ranges, exposure to oils and chemicals, outdoor climate, mechanical abuse, and other uncontrolled variables seen with industrial applications. The ability of industrial grade category cables to persevere under these conditions has become the standard expectation for product performance. Along with these very robust category cables, connectors of durable design, such as industrial grade RJ45 and M12 type connectors, must be used to provide protection in these settings to assure proper connectivity and long-term uninterrupted operation.
CATEGORY CABLE APPLICATIONS
The majority of category cables are used in industrial, commercial, or industrial/commercial combination setting. Not only do cable design attributes determine end use installation, but cable accommodating approvals also play a vital role. Cables with Appliance Wiring Material (AWM) are suitable for use within the confines of the industrial platform as per the NFPA 79 Electrical Standard for Industrial Machinery. However, when cables extend into the industrial or commercial infrastructure other listing types of approvals that are recognized by the National Electrical Code (NEC) are required.
The debate occurs when the cables transition from the factory platform to the industrial or commercial infrastructure. If the cables remain solely within the industrial platform then AWM will suffice as these applications fall within NFPA 79 guidelines. However, when cables are routed and exceed the confines of the industrial platform, certain “grey” area conditions can exist leading to possible installation issues. When category cables also maintain other approvals such as PLTC, PLTC-ER (NEC 725), CM, CMG, and CMR (NEC 800), end use installation suitability is further defined, and potential code violation is greatly reduced.
Generally, two category cable types, industrial and commercial grades, are used when transitioning from the industrial platform to industrial/commercial infrastructure. These two cables must then be connected via some type of termination method while at the same time minimizing the potential for any additional line loss. A range of connection methods can be used including hard wire splicing, terminal junction boxes, or adapter unions that transition from traditional consumer grade to industrial grade connectors. It is critical that these terminations be carried out only by those trained and qualified. If not done correctly, faulty operation or system shutdown can occur. Ideally, if a single cable could be used from the industrial platform to the industrial or commercial infrastructure, any additional line loss potential arising from the connection between the two transitioning cables would be eliminated.
One cable would be ideal, but industrial grade category cables with the correct approvals are generally more expensive than commercial cables. The aspect of cost is a very important topic amongst system designers, contractors. and installers. The cost of an industrial grade cable would require pricing relative to that of its commercial grade counterpart to be given consideration.
LAPP offers the ideal solution with its ETHERLINE® TRAY CAT. 7. This cable features increased speed and bandwidth performance requirements that will be mandated by the systems of tomorrow. Its many attributes include superior flame resistance, wide temperature range, outdoor exposure, mechanical durability, and oil resistance. Installation either on the industrial platform or the commercial/industrial infrastructure will be covered because this cable maintains AWM, CMG, CMR and PLTC-ER approvals. LAPP once again takes a leadership role by providing an innovative and competitively priced single cable solution which covers all the bases, from performance to installation versatility.