NI02 Telecommunications Bonding and Grounding - Industrial

PANDUIT Physical InfrastructureSM Solutions

Grounding & Bonding Systems

John French Technical System Engineer [email protected]

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Let’s Review Some Fundamentals…. 1. True/False: Electricity always follow the path of least resistance. A: This is FALSE. Electricity FAVORS the path of least resistance, but it follows all paths available to it.

2. True/False: Electricity wants to return to the Earth A: This is FALSE. Electricity always wants to return to it source. Only Lightening returns to Earth.

Design is Critical A properly designed grounding and bonding system is:

– Intentional, – Visually verifiable, – and Adequately Sized …to handle expected currents safely and without undue effect on susceptible electronic equipment.

What are the effects of Improper Grounding? Lower Reliability • An improperly designed grounding (and bonding) system may be a primary source of interference and emission. • According to the IEEE, the typical AC third-prong ground circuit is almost never sufficient to prevent damage to network equipment susceptible to ground-fault related potentials. • Poorly designed or improperly applied grounding, bonding, and shielding techniques often adversely affect the performance of electronic equipment – from the circuit board to the network system. • Approximately 70% of all anomalies, dysfunctions, or problems associated with power distribution systems are directly or indirectly related to bonding and grounding issues.

What are the effects of Improper Grounding? Safety Risks • Personal injury from electric shock caused by improper grounding and bonding can cause immeasurable human suffering and significant expense. • Potential fire hazards exist when heat is generated from electrical surges that occur on a high impedance grounding and bonding path.

“Device to Dirt” • The mistake most often made in any Network or Industrial grounding system is to not look past the closest connection when providing grounding for equipment being installed. • You see a ground point and make an assumption that the connection is a proper ground and that all connections leading from it go to the right place. • When is reality, this is very often not the case….

Let’s look at this example: There are three types of grounds referenced in electronics •

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•

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Chassis Ground: generally refers to using the chassis or frame of a device as a common return path and reference point for a circuit or circuits mounted on and electrically connected to that chassis or frame. Signal Ground: A return path for signals and power within a circuit and/or a connection between separate circuits and/or circuit boards. Also called “Circuit Ground” or “Circuit Common” Earth Ground: refers to a common return path with a direct physical connection to the Earth. Also called “Earth Return” and is done for safety purposes to protect people from the effects of faulty insulation. NOTE: The schematic symbol for Earth Ground is often used as a generic ground symbol. Though this is probably not a good practice.

That’s pretty straight forward, Right?

Just what does the term Ground indicate? • Ground wire terminated to case? • Case terminated to ground on electrical outlet? • Outlet ground tied to junction or power panel? • Neutral tied to ground at junction box? • Junction box tied to service entrance? • Ground lead tied to structure steel? • Ground tied to copper water pipe • Ground tied to ground rod?

How can we say the word “Ground” and mean so many different things?

Here’s another example: What’s the difference between a Common Ground and an Earth Ground? • A Common Ground is the point where many Equipment Grounds join together to be grounded to the ground with an Earth Ground!?! • Does that sound silly to you? • Confused?

Do you see any overlap in the symbols being used?

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Why is there such confusion? • For years the NEC Code interchangeably used the terms:

– Bonding, Grounding and Earthing. • Many countries outside the U.S. actually use the term Earthing to mean Grounding. • And almost no one uses the term Bonding for anything!

Understanding Grounding Systems To have a good conversation about Grounding Systems we need to establish a vocabulary to use to describe different areas of the system. We need to learn 3 terms:

• Earthing • Grounding • Bonding

Understanding Grounding Systems Earthing Earthing - Earth or a conductive body that is connected to earth.

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Understanding Grounding Systems Earthing

Grounding

Grounding – The point at which all “Bonded” conductors come together at “Earth”. SM

Understanding Grounding Systems Earthing

Grounding

Bonding

Bonding – Every other “ground” like connection inside the facility

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Understanding Grounding Systems Understanding these three things will alleviate MOST grounding issues within any facility. Earthing

Grounding

Bonding

Grounding and Bonding Infrastructure Grounding Electrode System • Electrode Types • Connection Types

Grounding and Bonding Infrastructure Telecommunications Grounding and Bonding Infrastructure Standard Requirements • TIA-607-B (revised J-STD-607-A ) • NECA /BICSI-607-2011 (New)

www.global.ihs.com

Grounding and Bonding Systems

Equipment Room’s with Access Floors Standard Requirements • TIA-607-B • NECA /BICSI-607-2011

Grounding and Bonding Systems

Equipment Room’s with a Slab Floor Standard Requirements • TIA-607-B • NECA /BICSI-607-2011

Grounding and Bonding Systems

Industrial Automation Applications

Grounding and Bonding Systems

Techniques for Control Panel Building

Control Panel Solutions

Defining grounding and bonding

NFPA 70-2011 (National Electrical Code, a.k.a. “NEC”) • Grounded (Grounding). Connected (connecting) to ground or to a conductive body that extends the ground connection. • Bonded (Bonding). Connected to establish electrical continuity and conductivity.

Grounding and Bonding 101

What is Grounding and Bonding?

A Grounding & Bonding System is most often associated with the protection of personnel, equipment and property from electrical disturbances caused by lightning, Electrostatic Discharge (ESD), surge or fault currents and transient voltages.

Grounding and Bonding 101

What Does Grounding Do?

• Provides a reference to earth to stabilize the system voltage for the Power Distribution System. • Provide paths for fault current to get back to its source without damaging equipment and facilitate operation of over current devices (breakers and fuses). • Promote equalization of electric potentials (voltages) between equipment, earth and personnel by bonding conductive paths together – Lightning – Electrostatic discharge

Grounding and Bonding 101

The Risks of Improper Grounding & Bonding Safety Shocks Fire hazards Lightning Insurance data: $500 million/year due to lightning damage Equipment failure Industry experts estimate 27-33% of damaged equipment due to ESD (Electrostatic Discharge) The risk of electrical noise The performance of shielded data cable requires proper bonding & grounding.

Grounding and Bonding 101

Lightning Lightning bolts can generate voltages in excess of 100M V Lightning is lethal of up to 60 ft or 600 ft in water from point of contact Lightning does not need a direct strike to induce electrical surges Transients can affect both overhead and buried cables Lightning can generate surges onto facilities of: 70 Volts at a distance of 1 mile (1.6km) 10K Volts at of 500 ft (150m)

Grounding and Bonding 101

Electrostatic Discharge Electrostatic charges are generated when different materials come into contact and are then separated.” Cables can acquire a charge during installation when they are unreeled from a cable reel, or dragged across a floor. There are reports of cables developing charge from moving air If you see or hear the ESD discharge it is a minimum of 2900V Here are some examples of voltages generated by ESD events: Walking across carpet: 1500 - 35,500 volts Picking up a plastic bag: 1200 – 20,000 volts Crossing your legs: 300 volts ESD Is greatly affected by Relative Humidity

Grounding and Bonding 101

ESD Protection Manufacturers ESD resistance is designed to work under normal operational scenarios All built-in ESD protection is worthless when the product is opened – must use external ESD protection Exposed printed circuit boards are most susceptible, like the ones found on plug-in cards or blades

Grounding and Bonding 101

Cisco on Grounding From the Catalyst 6500 Series Switch Installation Guide: “When you properly ground systems during installations, you reduce or prevent shock hazards, equipment damage due to transients and data corruption.” “Always use an ESD wrist strap…”. Use a 6 awg wire for the chassis ground. “Prepare the other end of the grounding wire, and connect it to an appropriate grounding point in your site to ensure adequate earth ground for the switch.”

Grounding and Bonding 101

What is required by “Code” for Grounding and Bonding in an IT Equipment Room? “the code says”

Per the NEC Article 645.15: “All exposed non-current carrying metal parts of an information technology system shall be grounded in accordance with Article 250 or shall be double insulated”. “we interpret non-current carrying metal as”

What are the non-current carrying metal parts? Racks, Cabinets, Zone Enclosures Metallic Cable Pathways: Ladder racks, Wire Baskets, Cable Trays Access Floor Structures Under-floor: conduits, dividers, water pipes

Grounding and Bonding Infrastructure The Grounding Electrode System

TelComm

To Building

Grounding Electrode System

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5 3

4

6

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The following grounding electrodes that are present MUST be bonded together to form the electrode system: 1. Metal underground water pipe 2. Metal frame of building or structure 3. Concrete-encased electrode (Ufer) 4. Ground Ring 5. Rod or pipe electrode 6. Plate electrode NEC Code Section 250.50

Grounding & Bonding Infrastructure

The Grounding Electrode System – Structural Steel

At least one structural metal member must be in direct contact with earth for 10 ft or more, with or without concrete encasement. Or Hold down bolts holding structural steel most be bonding to a concrete encased electrode in the support footing or foundation.

Grounding & Bonding Infrastructure

The Grounding Electrode System – Concrete Encased Electrodes

Shall consist of at least 20 ft of either • Steel reinforcing bar (REBAR) Or • Bare copper conductor of 4 AWG minimum.

Grounding & Bonding Infrastructure

The Grounding Electrode System – Rings, Rods, Pipes and Plates Ground Rings Minimum of a 20 ft, 2 AWG in direct contact with the earth Buried not less than 30 in. Ground Rods and Pipe Electrodes Both shall not be less than 8 ft. Pipe or conduit no smaller than 3/4” diameter and the outer surface galvanized Rod’s of stainless steel, copper or zinc coated steel shall be no smaller than 3/8” diameter Plate Electrodes Make at least 2 ft² surface contact with soil. Bare or uncoated iron or steel plates a minimum of ¼” thickness Do not use Gas Pipes or Aluminum for grounding electrodes

Grounding & Bonding Infrastructure

The Grounding Electrode System – Connection to the Grounding Electrodes

Article 250.70 Methods of Grounding and Bonding Conductor Connection to Electrodes. “The grounding or bonding conductor shall be connected to the grounding electrode by exothermic welding, listed lugs, listed pressure connectors, listed clamps, or other listed means. “

Types of Connectors allowed by Code and Standards Mechanical Connections Compression Exothermic Welding

Grounding & Bonding Infrastructure

The Grounding Electrode System Mechanical Connectors Typically used in residential. Can be removed or tampered with Prone to corrosion Requires maintenance Inexpensive Installs easier than compression and exothermic welding.

Grounding & Bonding Infrastructure

The Grounding Electrode System Exothermic Welding • •

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Typically used in commercial, industrial and Utility Produces a dangerous chemical reaction that heats to 4200F to make bond. Can cause serious burns and cause fires. Personal protective equipment and fire extinguishing equipment is required for installation. Storage of flammable materials required. Hazardous materials permits may be required in certain installations.

Grounding & Bonding Infrastructure

The Grounding Electrode System Exothermic Welding • Hundreds of combinations of molds and shots. Installation is more complex than both mechanical and compression connectors. • High failure rate / rework • Irreversible Connection • Excellent Corrosion Resistance • Inspection process is unreliable

Grounding & Bonding Infrastructure

The Grounding Electrode System Compression Connectors Typically used in commercial, industrial and utility. Irreversible Excellent corrosion resistance – tested to IEEE 837-2002 standards Installs easier and faster than exothermic welding. Less tools required; one crimp tool and (3) dies Can be easily inspected for proper installation

crimp process embosses die index number on part

IEEE Std 837™– 2002: Industry’s highest grounding connector performance specification • Purpose of 837: “guarantee that the connection will perform satisfactorily over the lifetime of the installation” • The 2002 version of IEEE Std 837 is significantly more stringent than the 1989 version • The 2002 test requires the resistance after lifestyle aging tests to vary by a factor of less than 50%, whereas the 1989 version allows resistance changes of up to 150%

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Why did IEEE revise the 837 standard in 2002? • Official reason was to clarify testing requirements • Reports from the field showed that buried connectors were sometimes degraded significantly • High levels of corrosion reported between connector and conductor • Grounding system failure results from this corrosion • When IEEE revised the test, the new acceptance criteria used ensures that connectors will better withstand the direct burial environment • The best measure of how degraded a connection has become is the resistance through that connection • Higher resistances at the end of the test sequence with respect to the resistances when the connections are first made are indicative of connection degradation

STRUCTUREDGROUND™ Direct Burial Compression Grounding The Grounding Electrode System and Entrance Facility

TMGB Conductor to ground rod Conductor to grounding electrodes

Conductor to building steel Conductor to conductor

12 connectors & 3 crimp dies meet all your grounding needs

Conductor to rebar

Compression connectors are capable of more current than the conductor connector

conductor

Compression vs Exothermic Welding Process

• Safety issues for installer minimized • No hazmat or hot work permits • No delays due to weather (precipitation and wind) • No forest fire danger. • Meets IEEE 837-2002 • 3 minute install vs. 7-15 minutes for exothermic per connector. • Inspection is simple, reliable and tested. • Fewer tools and supplies required • No Need to store flammable products

Compression works in extreme cold (e.g. -40o in northern Alberta’s oil sands)

Grounding & Bonding Infrastructure

The Critical Connections Industrial/Commercial Buildings

The application usually determines the performance level required and guides the design of the grounding electrode system. Substations

Communication Sites

Factors that will affect the design: • soil resistivity • temperature • moisture • minerals and salts in soil

Rail Roads

Wind Farms

Standards Change Telecommunications Bonding Backbone (TBB) Sizing J-STD-607-A (old)

TIA-607-B (new)

Design specifications, per TIA-607-B-1 • Commission a soil resistivity study The most common method of measuring average soil resistivity is the four-point method Require a series of readings in different locations to get a better idea of the soil conditions

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TIA-607-B-1 potential equalization design highlights

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Grounding and Bonding Systems

Telecommunications G & B Infrastructure Products Ground Bus Bars

2-hole Compression Connectors

Full line of connectors for the Telecommunications and Electrical Grounding Infrastructure

Copper Compression Taps and Covers

Beam Clamps

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Preventing loose busbar connections

Two-hole compression lugs

Telecommunications Grounding Busbar (TGB), BICSI/TIA-607 hole pattern

(Type LCC-W) (Type GB2B, or Part GB2B0306TPI-1)

BICSI-607 stainless steel TGB hardware stack-up (Parts HDW1/4-KT, HDW3/8-KT)

PANDUIT Tools Products Technical Support

Installation Tooling

HTAP Crimping • HTCT HTAPs require 12 tons of compression • CT-2930/L is recommended • Can use other manufacturers’ tools and retain UL Listing/CSA Certification • Must use Panduit locator dies

Patented locating rib guarantees fullwidth crimp 1st time, every time! CT-2930/L

HTCT HTAP

CD-930H-250 Locator Die

Do you already own the tools? • Panduit lugs can be crimped with select competitors’ tools and dies and still retain UL/CSA approvals • HTAP and direct burial GCE and GCC products can be crimped with competitors’ tools, but require Panduit dies and still retain UL/CSA approvals

Grounding and Bonding Systems

Installation Tooling

Grounding and Bonding Systems

Depth of Product Lines Terminals

Power Connectors Data Center Kits

Mechanical Grounding Compression Taps

Direct Burial

CTAPF

HTAP

CTAP

Grounding and Bonding Systems

Knowledge and Solutions for Multiple Applications Telecom Room

Data Center Telecommunications G&B Infrastructure

Grounding Electrode System

Entrance Facility

Control Panels

Grounding and Bonding Systems

We Can Help Technical Support Design Consultation Product Selection Specification Template Tool Selection

Knowledgeable Staff Product Literature White Papers Articles Part Drawings

Questions?

John French Technical System Engineer [email protected]

Thank You!