Monthly Archives: January 2017

How to Choose the Proper Cabling Pathway?

Just as the old saying goes: it’s the little things that make the biggest impact. This is especially true when it comes to design a data center—there are so many factors to consider during the process, among which the proper cabling pathway construction only possesses a small part yet matters significantly. Data center designers are always aware of that multiple products must work together to ensure a successful pathway and cable management. This article will take a review of the commonly seen cabling pathway types.

What Is Cabling Pathway?

Cabling pathways allow the placement of data center trunk cables and cross-connect cables between racks and cabinets. Cabling pathway comes into two forms: overhead pathway and under floor pathway. Both of them are designed to accommodate all standards-compliant cabling and allow for necessary changes later. In other words, cabling pathway should support the weight of cables in the initial installation and also facilitate additional cables in the future. Which helps ensure robust pathways that respond well to cable work over the facility’s life cycle.

cabling pathway

Cabling Pathway types Overview

Cabling pathway types come in a dazzle array of styles, in this section, we’ll illustrate some of them that widely used in work areas, wiring closets and for horizontal and backbone cable runs.

Conduit

Conduits are pipes that cable is placed in and pulled through, and it can be metallic or nonmetallic, rigid or flexible. They run from the telecommunications room to the work area outlets in the floor, walls, or columns of a building. To ensure that enough conduit be installed, it is recommended that the conduit would better be only 40 percent full by your current cable needs, or 60 percent full to the maximum. Which leaves you space for future growth.

conduit

Cable Trays

Cable tray serves as an alternative cabling pathway component to conduit, which can be installed as distribution system to route and support your cables. Typically, cable tray is open and equipped with sides that allow cable to be laid within the tray’s entire length. It is ideal to use cable tray to manage a large number of horizontal cable runs, due to their greater accessibility when it comes to maintenance and troubleshooting, as well as its ability to accommodate change.

cable tray

Basket Tray

A basket tray serves as a cable tray that designed for light duty applications, which is lightweight and easy to install. Unlike ladder rack installation, to properly install a basket tray, certain level of experience is needed. Many of the accessories that accompany ladder racks also accompany basket trays, to ensure proper bend radius and a proper transition to the equipment rack.

basket cable tray

Underfloor Cable Tray

An underfloor cable tray is used primarily in data centers. It resembles much as overhead support pathway types. However, when using under floor cable tray systems, the air space may be a plenum air space, so all cable and patch cables would need to be plenum to ensure proper air flow.

underfloor cable tray

Ladder Racks

A ladder rack is made of tubular steel and comes in sizes from 6’’ to 36’’ wide. The installation of a ladder rack is simple and requires little trade experience. Ladder rack comes with many accessories such as 90-degree bends, waterfalls and cable retaining posts. These accessories allow the routing of cable without damage.

ladder rack

Raceways

Raceways are special types of conduits used for surface mounting horizontal cables. They are usually pieced together in a modular fashion with vendors providing connectors that do not exceed the minimum bend radius. Raceways are mounted on the outside of a wall in places where cable is not easily installed inside the wall. They are commonly used on walls made of brick or concrete where no telecommunications conduit has been installed.

cable raceway

Installation Considerations for Cabling Pathway

With the purpose of supporting the current needs as well as future growth, several essential factors should better be considered while designing and installing cable pathway.

  • Overhead and underfloor cabling pathway should be installed in a matrix type method, allowing cables to be routed from point to point anywhere in the data center.
  • When installing any types of cabling pathway, grounding and bonding are rather vital. Make sure that all racks, cabinets, and cabling support components are properly bonded and the system is grounded.
  • Always leave room for future growth. All cable tray and ladder rack should allow room to accommodate at least 50% growth after the initial install.
  • Be sure the heaviest cable in on the bottom of the tray or separated from the lighter cables, and separate the copper cables from the fiber cables if possible.

separate fiber and copper in cabling pathway

  • Avoid mounting any types of cabling pathway in locations that block access to other equipment inside and outside the racks.
  • Avoid routing pathways with copper cables near equipment, which may generate high levels of electrometric interference. Avoid areas around power cords, florescent lights, building electrical cables and fire prevention components.
Conclusion

The knowledge concerning different styles of cabling pathway lies the foundation of proper installation of data center pathway. Choosing proper cabling pathway type makes it easier to perform cable-related work and maintenance later. Make your decision on the basis of your unique working condition and environments, and do not forget to account for the factors mentioned below while perform cabling pathway installation.

Cable Jacket: Should I Choose LSZH or PVC?

When talking about communication cables, we commonly use terms like LSZH and PVC to describe them. These two terms describe the chemical compounds used in production of the cables. As we might be rather familiar with these widely used terms, do you exactly know what they really mean? Or more importantly, which one is better for your project? In this article, we are going to explain these frequently asked questions, by analyzing and comparing LSZH and PVC cables.

Communications-Cable

What LSZH and PVC Stand for?

LSZH—Short for low smoke zero halogen, LSZH is a kind of cable built with a jacket material free from halogenic materials (such as chlorine and fluorine), since the toxic nature of these chemicals when burned. The term “low-smoke, zero-halogen” describes two distinct properties of a cable compound. The term “low- smoke” describes the amount of smoke which a compound emits when burned, while “zero-halogen” describes the amount of halogens used to make the compound. Terms like LSOH, LSHF and LSNH are all proper references for cables possessing low-smoke and zero-halogen properties.

PVC—Polyvinyl chloride (vinyl), a general-purpose plastic jacket material used for cables. Features low in cost and flexible, PVC cable is widely used in applications such as computers, communications and low voltage wiring. In the world of cabling, “PVC” is often used to denote a cable that is not suitable for use in a plenum airspace. PVC can potentially be dangerous in a fire situation, releasing heavy smoke and hydrogen chloride gas, which poses a great threat to human health electronic devices. PVC cables often have a CM, CMG, or CMR rating as defined by the National Electrical Code (NEC).

Differences Between LSZH and PVC Cable

Judging from the physical appearance, the difference between LSZH and PVC cable is very distinct. A PVC cable feels soft and it is smooth, whereas an LSZH cable feels rough since they contain the flame retardant compound and it is stiffer. LSZH cables are more aesthetically appealing than PVC cables. In addition to this, LSZH cable differs from PVC one in at least three aspects:

Cost: LSZH cables are slightly higher in cost than some PVC cables, but they are much safer when it comes to human health and sensitive and expensive electronic equipment. And this should be considered when comparing the cost.

Flexibility: Comparing with PVC compounds, there is a limited range of compound flexibility available for LSZH compounds, so LSZH cable is not recommended for robotic or continuous flex applications.

Heat: When a PVC cable is set on fire, it emits chemical fumes, acids and other toxic gases, which are both corrosive and harmful to human beings and environments. As for LSZH cable that has a flame-resistant jacket, it doesn’t emit these chemical substances even if it burns or exposed to high sources of heat. And it can reduce the amount and density of the smoke.

LSZH-PVC-differences

When Do I Use LSZH or PVC?

It is feasible that LSZH and PVC have equally effective performance in modern buildings. So the decision on which one to choose actually depends on the situation, that is to say, where you are going to run the cable.

PVC cable has been used in built environment for power and control applications for decades. It is commonly used for horizontal runs from the wiring center, or for vertical runs between the floors—but only if the building features a contained ventilation system running through the duct work.

LSZH cable would be more appropriate for places where fire presents a hazard to occupants. We known that the primary danger in the event of a fire is not the fire itself but the smoke and gas produced. Therefore, it is vital that the materials and products that are installed contribute as little smoke and gas as possible when burnt. LSZH cable can be employed in the following situations:

  • Confined spaces with large amounts of cables in close proximity to humans or sensitive electronic equipment, such as submarines and ships.
  • Mass transit, central office facilities and telecommunication applications.

LSZH-cable-application

Conclusion

Even though PVC cable still reigns supreme in wire and cable industry, the use of which has decreased over the past years. On the other hand, LSZH cable technology has advanced significantly, it is well suited to some applications mentioned in this article. Your cabling choice always relays on your specific condition, while to consult with wire and cable experts can also be beneficial.