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Proper Grounding, Bonding, Lightning & Surge ProtectionLightning & Surge Protection
By: Jeff Regan Telecom Market Manager
ERICO INTERNATIONAL CORPORATION CO O O
WHAT IS GROUNDING AND WHY DO WE DO IT?WHY DO WE DO IT?
GROUNDING (IEEE 100)( ) Definition:
A conducting connection, whether intentional or accidental, by which an electric circuit or equipment is connected to the Earth, or to some conducting body of relatively largethe Earth, or to some conducting body of relatively large extent that serves in place of the Earth.
Purpose:Used for establishing and maintaining the potential of the Earth (or other conducting body) or approximately that potential on conductors connected to it and for conductingpotential, on conductors connected to it, and for conducting ground current to and from the Earth (or other conducting body).
Why ground? y g
Equipment ProtectionOperate overcurrent device during a groundOperate overcurrent device during a ground
fault.Essential to proper operation of SPDsEssential to proper operation of SPDs
Noise Control (Computer Grounding) Lightning Dissipation
Why do we ground?y g
Required by CODE (NEC Article 250)Required by CODE (NEC Article 250) Personnel Safety
d i l diff bReduce potential differences between non-current carrying parts (enclosures) and b i dbetween non-current carrying parts and Earth.
SIX POINT PROTECTION PLANPLAN
BOND TO CREATE AN EQUIPOTENTIAL GROUND PLANE
What is Bonding? g
Interconnecting of all Ground Electrode Systemsg yElectrical Grounding SystemLightning Grounding System g t g G ou d g Syste Telecommunications Grounding SystemCable Grounding SystemCable Grounding System
Connect all conductive objects together both internal and external to the facilityand external to the facility
Provides near zero voltage difference during ground potential risep
Characteristics of a good ground system
Must comply with all local and national codes* NEC only contains minimum requirements
Good electrical conductivityy* Low impedance and resistance
Resistant to corrosion Resistant to corrosion* Copper is most commonly used material
Mechanically robust and reliable* Must perform for life of the facility (40 p y (
Copper vs. Galvanized Rods pp
Corrosion properties Corrosion properties Life expectancy UL requirements
Often overlooked in grounding system design Often overlooked in grounding system design Location and function of connectors Out of site, out of mind is the general rule What is the worst type of ground?yp g
Types of Connectors yp Brazed Mechanical (compression, bolted, wedge)
Rely on physical pressure to maintain connection Exothermic Welding
Molecular BondMolecular Bond
HOW DO I LOWER MY RESISTANCE?RESISTANCE?
Add more rods to the Systemy
ilproper rod , 2 x rod length. Minimum 1 x lengtho maintain proper rod spacingo maintain proper rod spacingIdeally, 2 x rod length. Minimum
l h1 x length
Alter The Soil Properties p Use a ground enhancement material Bentonite Clayy
Dependent upon moisture. Will wash away. New IEC 62561-7 GEM ground enhancement material
Hygroscopic, permanent, lower resistivity
Lightning Protection Lightning Protection Lightning Protection is Necessary! Required?
Examples of Lightning Damagep g g g
Lightning Protection Requirementsg g q A system that will take a direct
li ht i t iklightning strike A system that conducts lightning from
the building into the ground A system that eliminates massive y
structural damage and fire A system that helps stop theA system that helps stop the
infiltration of lightning along building systemssystems
How Lightning FormsHow Lightning Formso g t g o so g t g o s
E Fields 5-15kV/mE Fields >200kV/m
NFPA780-2000 Grounding/Bonding TechniquesGrounding/Bonding Techniques
Bond (Ground) Metallic Paths Entering Structure-Bond (Ground) Metallic Paths Entering StructureWater, Gas, Sanitary Sewer, Fire Prot., El. Grnd., Comm. Grd (Telephone, etc.), Process Piping
NFPA780-2000 Grounding/Bonding TechniquesTechniques
Difference of Potential between
grounded building systems andsystems and
the lightning protection system
Current Distribution in non-ideal Faraday CageFaraday Cage
Lightning ProtectionLightning Protection System - Multiple
Lightning Protection - Maintenance System should be checked every two years
ll i i l b bl i l All air terminals, bases, cables in place OHM resistance checked on system New roof-top equipment needs to be added to
systemh k f f h l d Check structures for signs of physical damage
Re-roofed? System should be inspected by LP i t ll d/ ULinstaller and/or UL.
Building additions/attachments needed to be incorporated into lightning protection systemincorporated into lightning protection system.
What killed the Cows?
Copper Theft - A BIG Problem!pp
Lose of Ground Connection!
Stolen Ground Bar
Solutions to TheftERICOs Solutions to Reduce Copper Theft ERICO offers two types of solutions aimed at minimizing or eliminating theft of
f di t i t l i ticopper from grounding systems in telecommunications.
1) Alternative Conductors to Copper 2) Alternative Ground Bars to Copper
All of the solutions should be complimented with clear signage at the site statingthat the conductors are not copperthat the conductors are not copper. Alternative Conductors to Copper Copper is not substituted easily with other materials because of its uniquepp y qproperties in terms of its conductivity and corrosion. However there are a number of conductorsolutions available that can retain the use of the copper properties but yetchange the composition so that it is of little or no scrap value. The conductorsdiscussed here are well suitable for grounding applications. These newerconductors are also suited for other non-grounding applications. Theft Deterrent Composite Cable. TDCC This is a bare concentric stranded conductor that consists of peripheralThis is a bare concentric stranded conductor that consists of peripheralgalvanized magnetic steel stranding, which protects and conceals the internaltinned copper stands. This conductor is ideal for exposed locations where coppertheft may occur. The conductor is difficult to cut with hand tools, and the outersteel stranding is ferrous, which further deters thieves looking for copper. Copperstranding inside of conductor increases conductivity and conductor flexibility.Copper stranding is tinned for superior corrosion protection
Theft Deterrent Cables
Copper Bonded Steel ConductorsppHigh carbon steel core, low scrap value! Above or below grade usescrap value! Above or below grade use
Ground Bar Replacements -TDSGAp
Alarms sometimes work!
Are You Prepared? p Lose of ground media to your site can be
d i !devastating! Do a maintenance check on all ground
systems. Check Ohm readings, visually check for stolen conductors, bars, etc.
Replace ground systems with Theft Deterrent conductors and assemblies.
One lightning strike can damage equipment and lose of life: Be Prepared!and lose of life: Be Prepared!
COMMENTS, QUESTIONS?Thank You!