Electromagnetic Compatibility | Progressive Office Cabling

Directions in Telecommunications and Cabling

3 Apr 2015

The telecommunications industry continues to advance. And bandwidth demands will continue to increase. Meanwhile, conditions to convey considerable amounts of information quickly are changing. Applications including graphic information, technical modeling, video conferencing, and multi-level online databases will certainly increase bandwidth requisites. The bottom line is demand for higher transfer speed for information is expected to rise.

Properties for Cabling Systems

Two principal properties needed for cabling systems are performance and easy installation. Fiber and shielded twisted-pair provide stronger signals compared to Unshielded Twisted Pair (UTP) although these two lagging in client acceptance. The question is will UTP provide the appropriate bandwidth for modern applications?

Unshielded Twisted Pair

UTP is considered the most prevalent cable worldwide for telecommunications and networking. Cat 5e is the most popular and it long ago replaced coaxial cable which failed to keep up with more dependable and faster networks. UTP is also easy to install, develop and troubleshoot. Unshielded Twisted Pair cabling does not have any foil covering. It depends on twisted pairs inside the cable to prevent electromagnetic interference. UTP is used extensively for local area networking and comparable cabling configurations. Hence, installation is easier and less expensive.

Shielded Twisted Pair

Shielded twisted Pair (STP) features a metallic foil enclosing twisted wire pairs inside the cable. This is the safeguard against electromagnetic intervention which facilitates rapid data transmission. STP functions by drawing electromagnetic interference and counterbalancing this with grounded cabling. The drawback is that if the cable is not grounded correctly it loses the capacity to prevent unnecessary noise. STP is also larger and more sensitive compared to UTP cables. Expert cable installers use this cabling for industrial environments where adjacent equipment emit significant amounts of elctron-magnetic interference (EMI). Actually, UTP and STP can perform well if installed and maintained by efficient cabling providers.

Transmission is Essential

Transmission should be balanced. This is the standard for conduction of data using twisted cabling pairs. Separate protection for balanced twisted pairs is designed to enhance resistance and emission of the communication lines. The shielding method produces a conductive barrier that lessens these electromagnetic waves. It also creates a conduit for conduction so that currents and can pass data through without any obstruction. Shielding can be performed on individual pairs or as one set of pairs.

Please contact us if you have any questions or concerns or if you need a free quote on your cabling project.

About Ethernet Cables and Data Shielding

7 Dec 2014

Stu Kushner

Network cabling, cables,shielding The Ethernet network cable connects devices on a LAN (local area network) such as personal computers, switches and routers. These cables are typically Cat5 and Cat6. These cables provide the infrastructure that connects the PCs, printers, router/modem and other peripherals to a switch. The cables are made up of stranded or solid copper wires. Stranded wires are not as susceptible to fractures but are more difficult to terminate. Solid Cat5/Cat6 also is less susceptible to electrical interference. These shielded cables are made up of braided strands of copper wrapped in a polymer layer and spiral copper tape. The shield is applied across the splices.

An Ethernet cable can be compared to an electrical power cord in that it can only extend a limited distances because of the electrical transmission properties. Meanwhile, wireless technologies (Bluetooth and Wi-Fi or local wireless technology) have enhanced the reach of Ethernet in residential and enterprise networks. The standard Ethernet cable consists of four coiled pairs that terminate at the eight pins of the clipped connector or "RJ45" at both ends of a cable. At the wallplate is simply the female end of the same connector. The cable is made up of unshielded (UTP) or shielded twisted-pair (STP) cabling.

Shielding is not selected automatically during installations. The answer is, it affords the protection required for certain environments although there are also some downsides. One is mass. The single-shielded cable made of Ethernet weighs approximately 12 percent more than the unshielded cable. The double-shielded version is roughly 30 percent heavier. You may be putting together dozens or perhaps hundreds of individual shielded twisted-pair cables along a ladders tray above the ceiling, under a floor, or at the back of panels. The aggregate weight of these cables can collapse the mounting bracket.

Cable flexibility is also an important issue. Take care when you pull the cables through conduits. The cable shielding can make installation more difficult. The sole foil shield can crack while the sharp boundaries of the shield can scrape the insulation of individual wires. This can cut the wire and cause data transmission issues.

What are the shielding options?

You have a number of shielding choices in for your Ethernet network. The single-shielded cable has the lightest protection. Double-shielded cables contain a foil and plate shield. It can ensure better protection against electromagnetic or radio frequency interference and reduce issues related to cable relocation. High-flex industrial cables are fabricated and protected for uninterrupted applications. These have special jacket materials to address industrial and outdoor concerns.

What is “Alien Crosstalk”?

8 Mar 2013

Stu Kushner

Network Cabling, Data Cabling No, it’s not ET calling home. “Alien Crosstalk” is defined as “unwanted signal coupling from one balanced twisted-pair component, channel, or permanent link to another”.

Alien crosstalk is not generally affected by common noise from motors, transformers, or florescent lighting fixtures. Alien crosstalk is specified as “a parameter for cabling to approximate the energy present when all cabling pairs are energized”.

Shielded or Unshielded Cat6 cable?

22 Feb 2013

Stu Kushner

cat6-cabling,data cabling, With high bandwidth applications and network systems venturing into factory environments, the need for shielded Cat 6 cable has increased. In these new areas of installation, the environment where the network cable is run has large amounts of EMI (Electro-Magnetic Interference). Although Cat 6 cables have improved cable twist to reject noise and handle gigabit Ethernet this by itself is not enough for high EMI environments. A shielded Cat 6 cable helps in high EMI installations. These high performance cables ensure the data within the cable will be protected from EMI, resulting in higher speeds and better data transmission.

Grounding Necessities for Shielded Cat 6 cables

Shielding helps protect the data from electromagnetic interference from outside sources that could alter or weaken the signal traveling through the copper in the cable. The shields of the two connectors are electrically tied together by the drain wire. However, they will only become grounded if the jack they are placed in has its shielding tied to ground. If you are setting up a network with Category 6 shielded cables, you should use Cat 6 shielded couplers and jacks.

Installation caveats

Category 6 and 6a cable must be properly installed and terminated to meet specifications. The cable must not be kinked or bent too tightly (the bend radius should be at least four times the outer diameter of the cable). The wire pairs must not be untwisted and the outer jacket must not be stripped back more than 1/2 inch (1.27 cm).

All shielded cables must be grounded for safety and effectiveness and a continuous shield connection maintained from end to end. Ground loops develop when there is more than one ground connection and the difference in common mode voltage potential at these ground connections introduces noise into the cabling.