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Grounding & Bonding

Forward-thinking organizations are increasingly relying on IP networking to collect and control the real-time information necessary to compete in the modern business climate.


November 1, 2008  


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Forward-thinking organizations are increasingly relying on IP networking to collect and control the real-time information necessary to compete in the modern business climate.

This demand for IP communications is bringing about the convergence of traditionally disparate infrastructure systems including communications, computing, power, control and security.

As the interdependence of these systems increases, so does the complexity of the physical infrastructure required to support reliable network operation.

One critical element of the physical infrastructure is the telecommunications grounding and bonding system, which includes primary fault current pathways via the serving power circuit and any supplemental grounding and bonding structures.

A properly designed and maintained grounding and bonding system improves the reliability of the physical infrastructure by minimizing the harmful effects of transient voltages and electrical surges.

As the convergence of this and other infrastructure systems increases, organizations need new approaches to managing risk throughout the physical infrastructure to enhance network reliability.

Integrated grounding and bonding systems eliminate some of the complexities associated with system convergence, integration, and interdependency by integrating key performance aspects into system design. These structured (or designed) systems provide both required and supplemental grounding and bonding paths within the system. This integrated approach reduces the effort required to install and maintain the grounding system and helps ready the network for the ongoing convergence of other systems.

Overall goals

The two fundamental goals of a well-designed grounding and bonding infrastructure are to:

• Provide engineered, adequate capacity paths for fault current to return to their source without damage to equipment or personnel.

• Substantially equalize electrical potentials among various lineups and metal structures by interbonding nearby conductive paths

Industry standards documents such as IEEE Std. 1100-2005, TIA-942, and J-STD-607-A provide guidance on how to accomplish these goals. Following the guidance of industry standards is also an important step towards creating a design that supports the vision of a U/L to align, converge, and optimize systems over time (see sidebar).

For example, properly bonded racks and cabinets are optimally equipped to handle the various ways that devices within the network are grounded.

This helps to eliminate the chance of a grounding system failure at a certain point, regardless of whether the equipment bonds through its mounting flanges or through a grounding pad located somewhere on its chassis.

UPI-based products integrate the goals of the standards within the very designs of the products themselves. For structured grounding systems, this approach involves providing features that promote both required product safety and supplemental grounding and bonding paths.

These systems improve the physical infrastructure by providing a more robust solution with less risk that the deployed infrastructure will be installed improperly or perform unreliably.

Integrated Grounding and Bonding Systems: UPI design principles encourage the use of integral bonding features to ensure that all components are electrically bonded to each other as they are installed.

Knowing that the entire infrastructure (including racks, cabinets, and pathways) is electrically continuous enables network stakeholders to make confident decisions about other infrastructure systems when deploying technologies such as shielded cables.

The integration of the bonding mechanism for a cabinet door hinge into the hinge design automatically makes the bond when the door is installed or reinstalled.

Compare this with the standard industry practice of using a small jumper to bond cabinet doors to the frame: if the cabinet door is removed, the possibility exists that the bonding jumper will not be reinstalled when the door is put back.

Another example of integrated system design is the use of underfloor cable pathway designs that, when assembled, automatiwww.

cally create electrical continuity and bonding to the mesh common bonding network (MCBN), as described in IEEE Standard 1100-2005.

Such designs remove the need for dedicated bonding jumpers between basket sections, and eliminate the concern that electrical discontinuities exist because either a bond was not made or because a wire could be damaged or removed at some point in the future.

These integrated designs also reduce cost by eliminating the need for extra grounding components and the time required to install them (see Figure 1).

Finally, factory-assembled grounding and bonding jumper kits (like the one shown in Figure 2) help ensure the integrity of the telecommunications grounding and bonding system in two ways: they save the installers minutes of time for each termination (wire stripping to the proper length, selecting dies, making the crimps), and they help error-proof the installation by promoting standardization while providing the proper gauge of wire, termination type, and bonding hardware.

This ensures that adequate electrical continuity and mechanical strength exist when the installation is complete.

Coordination Among All Project Stakeholders is Essential: Component incompatibilities (i. e. components that do not mate properly resulting in loose connections with high electrical resistances) and system discontinuities (such as missing bonding connections) plague todays grounding and bonding infrastructures.

These issues often can be traced back to lack of effective coordination between stakeholders along the entire project life cycle from the design phase to procurement and installation.

Key responsibilities of designers include specifying a standards-based system layout, and communicating which project team members are expected to procure and deploy each part of the grounding and bonding system.

Designers and other project managers also should encourage regular communication between team members throughout the project, especially between electrical and data contractors, to ensure that the products each is installing are compatible with one another, and that all aspects of installation and testing are covered.

Setting these expectations up front drastically reduces the chance for errors during installation, and a standards-based design enables improved maintenance times.

Best in class vendors contribute to this coordination effort by performing rigorous operability tests on system components to ensure reliability even before they are delivered to the site.

For example, NEBS Level 3 testing is the superior test of operability for lugs and other power connectors to support network reliability and availability goals. These operability tests go beyond the normal certifications done by nationally recognized testing laboratories by exposing components to simulations of real-world events, such as earthquakes, corrosion, and temperature cycling to ensure that the grounding and bonding system will protect the physical infrastructure even during severe circumstances.

In conclusion, the telecommunications grounding and bonding system is an integral component of a UPI-based offering as it improves the reliability of the infrastructure as a whole. Implementing this system in an intentional and systematic way reduces the risk of error and minimizes the grounding and bonding installation and maintenance efforts. CNS

Tom Turner is the business development manager at Panduit Corp. based in Tinley Park, Ill. He can be reached via e-mail at tjt@panduit.com.

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A properly designed and maintained system improves the reliability of the physical infrastructure by minimizing the harmful effects of transient voltages and electrical surge
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One critical element of the physical infrastructure is the telecommunications grounding and bonding system.