Attach 13 COMM grounding-n-bonding Reference.pdf

Telecommunication Grounding & Bonding

Anthony I Madroño

RCDD DCDC HP-AIS CAP-RS REE MBA

Managing Director – ISI Corp Member - IEEE

Lifetime Member – IIEE Philippines BICSI Chair

Codes and Standard References

• ANSI J-STD 607B

• ANSI/NECA/BICSI 607:2011

• ANSI/TIA 607B: 2011

• BICSI TDMM 13th Edition:2014

• BS 7430:2011

• IEEE 1100:2005

• IEEE 81:2012

• ISO/IEC 30129:10.2015

• NFPA 70:2014 (NEC)

• Motorola R56:2005

Why the need for Grounding and Bonding

• Equipment Protection

• Satisfy Warranty Requirement

• System Performance

• Service Protection

• Personnel Safety (code requirement – NEC/CSA/BS/IEC)

Case: Two Ground Reference Points

Effect of Two Earth Reference Points (voltage difference between two equipment)

Case: Single Equipotential Plane

Effect of Single-point Reference of all Equipment (0 volts Difference)

1. Grounding & Bonding Components

Main Telecommunication Grounding Busbar

(TMGBB)

Telecommunication Grounding Busbar

(TGBB)

2-Hole Long Barrel Terminal Lugs & Compression Type Connectors

Exothermic connection & a 2-hole lug connection to a busbar

2-Hole Terminal Lug

Trimmed Insulation from a conductor

Conductor seen Through the inspection port (window)

1. Grounding & Bonding Components

1. Grounding Rods Plates & Pipes

Ufer Grounding Method

Copper Ground Rod

Building Frame & Water Pipe Bonding

Copper Plate Grounding

1. Grounding Rods Plates & Pipes

2. Preparations - Crimping & Exothermic Welding

Crimping a conductor in the barrel of the lug

Finished Barrel with 3-crimps

Mold being locked and disk inserted

Example of a mold for an exothermic weld

2. Preparation - Exothermic Welding & Busbar

Pouring Weld metal powder into a mold

Igniting the accelerant

Removing oxidation from the grounding busbar

Applying an antioxidant to the cleaned area of the grounding busbar

Attaching a lug to the grounding busbar

Lug mounting configuration

Example of a TEBC to Rack bonding conductor connection

2. Preparation - Busbar Lug Connection

3. Sample - Bonding Connection with Rack Cabinet Door System

Illustration of a bond connection from a cabinet to the cabinet door & side panel

3. Sample - Mechanical & Exothermic Bonding Connection

Example of Mechanical Connector Shall Be UL listed for the purpose - Always

Example of Exothermic Welding

Example of bonding jumper and its installation between cable tray segments

Example of 2-hole lugs and a ground terminal block & Clips

3. Sample - Mechanical Bonding on Trays

Example of a TEBC routed on a cable tray -bend radius shall not be less than 200mm & 90 degrees minimum

Illustration of a connection point to a rack from a TECB

3. Sample - Tray Bonding Routing & Radius

3. Sample - Rack Bonding Configurations

Three methods to bond equipment & racks to ground

Illustration of acceptable and Unacceptable equipment bonding

3. Sample - Rack Bonding Configuration

TGBB should be closest possible to the Electrical Panels – Bond Everything!!

4. Set Up - TGBB Grounding in an IT Room

4. Set up - Components of grounding & Bonding System

Note that on the ISO/IEC 30129 (released Oct 2015) Standard for Information Technology :

Telecommunications Bonding Networks for Buildings and other structures – GEs (Also known as Bonding Equalizer) must be made every other 3 floors and the top floor.

4. Set up - Components of grounding & Bonding System ISO/IEC Referenced

TIA 607-B & ISO/IEC 30129

Maximum TMGBB (PBB) to TGBB (SBB) Length (L) meters (feet)

Conductor cross-sectional area (minimum)

Nominal Int'l Conductor (mm2)

Nominal AWG Conductor

L ≤ 4m (13ft) 16 6 4 < L ≤ 6m (14 – 20ft) 25 4 6 < L ≤ 8m (21 – 26ft) 35 3 8 < L ≤ 10m (27 – 33ft) 35 2

10 < L ≤ 13m (34 – 41ft) 50 1 13 < L ≤ 16m (42 – 52ft) 60 1/0 16 < L ≤ 20m (53 – 66ft) 70 2/0 20 < L ≤ 26m (67 – 84ft) 95 3/0 26 < L ≤ 32m (85 – 105ft) 120 4/0 32 < L ≤ 38m (106 – 125ft) 150 250 kcmil 38 < L ≤ 46m (126 – 150ft) 150 300 kcmil 46 < L ≤ 53m (151 – 175ft) 185 350 kcmil 53 < L ≤ 76m (176 – 250ft) 250 500 kcmil 76 < L ≤ 91m (251 – 300ft) 300 600 kcmil Greater than 91m (301ft) 400 750kcmil

For lengths in excess of those shown above, the conductor cross-sectional area should be calculated as 3.3mm2/m or 2kcmil/ft.

5. Sizing Up all Conductors – Main Bonding Conductors & Bonding Jumpers

5. Sizing Up all Conductors – Bonding Conductors or Bonding Jumpers

5. Sizing Up all Conductors – Bonding Conductors or Bonding Jumpers

5. Sample Conductor – Main Grounding Electrode Conductor

5. How to do It :

Main Grounding Electrode - Position

5. How to do It :

Main Grounding Electrode - Depth

DEWA = 6 meters apart Minimum

NPFA 70 = equal to the length of the Rod – minimum, with recommended spacing of twice the length of the Rod

5. How to do It :

Main Grounding Electrode - Spacing

DEWA = Dubai Electric & Water Authority

6. Testing – What numbers to look at?

Typical Ground Resistance Requirements – Which one to Follow!

Type “A” Sites: (One Rod or Two Rods Grounding Systems)

• NFPA 70:2017 (NEC) = 25 Ohms or use two rods or more

Type “B” Sites: (Two or more Rods Grounding Systems in ring/radial or special set up)

• IEEE Standard 1100 = 1 Ohm (125Vac L-G) USA = 0.8 Ohm (277Vac L-G) USA = 0.8 Ohm (347Vac L-G) Canada

• Motorola Standard R56 = 10 Ohms (Design Goal – 5 Ohms Recommended)

• Telecommunications Cos = 3 to 5 Ohms, Regional TELCOs Less than 10 Ohms

• GE & Other Medical Systems = 2 Ohms

• ANSI/BICSI 002:2014 = 5 Ohms Maximum, but recommends

3 Ohms for Class F2 & F3 DC, and 1 Ohm for Class F4 Data Centers Design

• DEWA - Dubai = 1 Ohm (Section 5.2.4 – 1997Ed)

• TEWR - Abu Dhabi = 10 Ohms (Section 6.2.1a – 2014ed)

6. Testing - Option 1 = Fall Of Potential

Components of resistances in an earth Electrode

(Effective Resistance Area)

Reference: IEEE 81:2012 = Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Grounding System

How to Space the Current Probe from Electrode to be Tested?..... How Far!

On a Single Electrode

* Minimum Distance = 5 Times the Length of the Rod

* Ideal? = 10 Times the Length of the Rod

@ 10FT Rod, Current Probe = 100Feet Away

Note: In numerous test on soil with uniform soil resistivity it has been found that ground’s resistance is at around 62% (some documents says at 61.8%) away from the rod under test!! Hence Fall of Potential Method is also known as 62% Method of Ground Resistance Testing.

Abu Dhabi – The Electrical Wiring Authority Manual (3rd Ed – 2014) Appendix A19(a)

6. Testing - Option 2 = Clamp-on Testing Clamp-on Ground Resistance Meter

* Does Not Require Disconnecting Equipment

* Measures Current on the Ground to get Ground Resistance,

* Referenced with Pole Butt Proper and consistent resistance, and

* Very Convenient, Quick & Easy However, it may read Ground Loops instead of Ground Resistance!!

Abu Dhabi – The Electrical Wiring Authority Manual (3rd Ed – 2014) Appendix A19(a)

7. Bond it Together - Follow the Codes

NFPA 70:2017

Art 800 Communication Circuits Section: 800.100(D)

Bonding of Electrodes. A bonding jumper not smaller than 6AWG (14mm2) copper or equivalent shall be connected between the communications grounding electrode and power grounding electrode system at the building or structure served where separate electrodes are used.

7. The Key? – Just Bond It Together!

• Commercially available electrolytic ground rods should be considered.

(MIL-HDBK-419A Volume I, and UL 467-2013)

• These are in straight or L-shaped versions. Generally constructed of 54 mm (2.125 in.) dia. hollow copper pipe and filled with a mixture of non-hazardous natural earth salts.

• Holes on the pipe allow moisture to be hygroscopically extracted from the air into the salt within the pipe, hence forming conductive electrolytes and leach out from the pipe into the soil, thus improving soil conductivity.

• Electrolytic ground rods are inserted into a pre-drilled hole, or in the case of L-shaped rods, placed into a trench at least 762 mm (30 in.) deep, and encased in a grounding electrode encasement material.

8. Area with Poor Soil Conductivity Option 1: Electrolytic Grounding Rod Systems

Option 1: Electrolytic Grounding Rod Systems

Requirements and use of ground plate electrodes are as follows:

• Ground Plates shall be UL listed using copper or copper-clad steel plates.

• It shall expose not less than 0.37 m2 (2 sq.ft.) of surface to exterior soil (MIL-HDBK-419A, NFPA 70-2017, & NFPA 780-2017).

• It shall have a minimum thickness of 1.5 mm (0.06 in.) (MIL-HDBK-419A, & NFPA 70-2017).

• Ground plates shall be free of paint or other nonconductive coatings (NFPA 70-2017, &

NFPA 780-2017).

• It shall be buried not less than 762 mm (30 in.) below the surface of the earth (NFPA 70- 2017).

• Where practical, a ground plate shall be embedded below permanent moisture level (BS

7430:1998, & NFPA 70-2017).

• Ground plates should be installed vertically to allow for minimum excavation and better contact with the soil when backfilling (BS 7430:1998 and IEEE STD 142-1991)

Option 2: Copper Plates Grounding Systems

• Though concrete-encased electrodes (also known as Ufer electrodes, or foundation earth electrodes - named after Herbert G. Ufer, ), they should be used in new construction as a method of supplementing the grounding electrode system (IEC 62305-3).

• It enhance the effectiveness of the grounding electrode system in two ways:

* the concrete absorbs and retains moisture from the surrounding soil, and

* the concrete provides a much larger surface area in direct contact with the surrounding soil. (This is especially helpful at sites with limited area for installing a grounding electrode system).

• See IEEE STD 142-1991 section 4.2.3, and the International Association of Electrical Inspectors publication, Soares Book on Grounding and Bonding, 9th Edition, for added information.

Option 3: Ufer Grounding Systems

Requirements for a concrete encased electrode, if used, are listed as follows (IEC 62305-3, NFPA 70-2017, and NFPA 780- 2017):

• Concrete-encased electrodes shall be encased by at least 51 mm (2 in.) of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth (or ground).

• It shall be at least 6.1 m (20 ft.) of bare copper conductor not smaller than 25 mm2 (#4 AWG) or at least 6.1 m (20 ft.) of one or more bare or zinc galvanized or other conductive coated steel reinforcing bars, or rods at least 12.7 mm (0.5 in.) in diameter.

• And, shall be bonded to any other grounding electrode system at the site as per NFPA 70-2017.

BS 7430:2011 (Code of Practice for Protective Earthing of Electrical Installations)

ISO/IEC 62305-3 (Protection of Structure Against Lightning)

IEEE 142:2007 (Green Book – Grounding of Industrial & Commercial Power Systems)

Motorola R56 (Standards & Guidelines for Communication Sites)

MIL-HDBK-419A (Military Handbook Grounding, Bonding & Shielding for Electronic Equipment & Facilities)

MIL-UFC-3-580-01:2016 (Military Unified Facility Command Telecommunications Interior Infrastructure Planning & Design)

MIL-I3A Standard 2010 (Military Technical Criteria for the Installation Information Infrastructure & Architecture)

UL – 469:2013 (Grounding & Bonding Equipment)

9. Reading References for Grounding & Bonding Specially on Areas with Poor Conductivity Soil

Conditions

10. Where to Buy Codes and Manuals mentioned www.bicsi.org www.iso.org www.global.ihs.com www.tiaonline.org http://www.bicsi.org/ http://www.iso.org/ http://www.global.ihs.com/ http://www.tiaonline.org/

Anthony I Madroño

Contact: +63.899.4278 & 80 +63.917.540.0842

Email: tony.isicorp@gmail.com

Thanks a lot

Telecommunication Grounding & Bonding