The National Electrical Safety Code ("NESC")
Presented by
Lauren E. Gaunt, P.E.
Principal Engineer, Eversource Energy
Senior Member, IEEE
Mark A. Konz, P.E.
Customer Service Organization Training
Supervisor, Gulf Power Company
U.S. -- Africa Clean Energy Standards Program
Clean Energy and Electrical Safety Workshop
May 16, 2016
Cape Town, South Africa
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Introduction to the National Electrical Safety Code ("NESC")
• The NESC is a consensus standard prepared by the National
Electrical Safety Code Committee under procedures approved by
ANSI.
• NESC Committee membership includes national and international
organizations. Is certified by ANSI as having an appropriate balance
of the interests of members of the public, utility workers, regulatory
agencies, and the various types of private and public utilities.
• The NESC is used in whole or in part by statute, regulation, or
consent as the standard (or basis of the standard) of safe practice
for public and private utilities in the United States, as well various
jurisdictions and industries in other countries.
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Without a Set of Safety Rules…
What Might Happen?...
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NESC: 100 Years of Safety
•
U.S. Congressional mandate
— In 1913, the US Congress requested the National Bureau of Standards
(“NBS”) to develop the NESC to bring consistency and safety to the design,
construction, operation, maintenance and use of electric supply and
communications throughout the United States
•
Industry consensus sought
― NBS brought together representatives from electric utilities, telephone
utilities, railroads, and factory owners to identify and discuss commonalities
between systems, common problems, and potential solutions
•
Standardization needed
— Early electric supply and communication systems were isolated systems
constructed without standardization of clearances, strengths of materials,
construction methods or operation, causing problems for both public
vehicles and electrical workers travelling from one area to another or
working in different manufacturing facilities
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NESC: The IEEE Role
In 1972, IEEE was designated as the secretariat for the NESC. The
IEEE performs all administrative functions for the NESC Committee.
The IEEE is the publisher of the NESC and owns the copyright for
NESC.
• Permission must be obtained from IEEE to use portions of
NESC
• Permission not required to reference NESC
The NESC continues to be a stronghold in the U.S. electrical industry
and communications utility field, and serves as the authority on
safety requirements for power, telephone, cable television, and
railroad signal systems.
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NESC Purpose
The purpose of the NESC is the practical safeguarding of persons, and utility
facilities during the installation, operation, and maintenance of electric supply
and communication facilities, under specified conditions.
NESC rules contain the basic provisions, under specified conditions, that are
considered necessary for the safeguarding of:
1. The public,
2. Utility workers (employees and contractors), and
3. Utility facilities.
NESC rules are intended to provide a standard of safe practices that can be
adopted by public utilities, private utilities, state or local utility commissions or
public service commissions, or other boards or bodies having control over safe
practices employed in the design, installation, operation, and maintenance of
electric supply, communication, street and area lighting, signal, or railroad
utility facilities.
The NESC is not intended as a design specification or as an instruction manual.
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The NESC covers: (List Not Comprehensive)
1. Supply and communication facilities (including metering) and
associated work practices employed by a public or private
electric supply, communications, railway, trolley, street and
area lighting, traffic signal (or other signal), irrigation district
or other community owned utility, or a similar utility in the
exercise of its function as a utility.
2. The generation, transmission, and distribution of electricity,
lumens, communication signals and communication data
through public and private utility systems that are installed and
maintained under the exclusive control of utilities or their
authorized representatives.
3. Utility facilities and functions of utilities that (a) either generate
energy or signals or accept energy or signals from another
entity and (b) provide that energy or signals through a delivery
point to another entity.
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The NESC does not cover: (List Not Comprehensive)
1. Utilization equipment or premises wiring located beyond utility
service points to buildings or outdoor installations, or
2. Underground mine wiring or installations in ships, railway rolling
equipment, aircraft, or automotive equipment, or
3. Luminaires not installed or maintained under exclusive control by
utilities, or
4. Industrial complex or utility interactive systems that are not
controlled exclusively under utilities or qualified persons or are
located on the premises wiring side of the service point.
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Scope: Figure 011-1
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NESC Committee Members
• Edison Electric Institute
Members of the
Committee are
organizations,
associations, and
government
agencies which
are national in
scope, all having
a direct and
material interest
in the activities of
the Committee,
for example:
• International Brotherhood of Electrical
Workers
• American Public Power Association
• Alliance for Telecommunication Industry
Solutions
• Solar Energy Industries Association
• IEEE
• National Association of Regulatory
Commissioners
• National Cable Television Association
• Others
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Committee Members Continued
The NESC consists of:
• The NESC Main Committee,
• 7 technical Subcommittees,
• The Executive Subcommittee, and
• An Interpretations Subcommittee
Over 150 participants
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NESC Subcommittees and What They Cover
SC1- Coordination - Sections 1, 2 and 3;
Coordination between technical subcommittees
SC2- Grounding Methods - Section 9
SC3- Electric Supply Stations - Sections 10-19
SC4- Overhead Lines - Clearances - Section 2023
SC5- Overhead Lines - Strength and Loading Sections 24-27
SC7- Underground Lines - Sections 30-39
SC8- Work Rules - Sections 40-43
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NESC Parts
The NESC is comprised of 5 parts:
•
Section 9: Rules for Grounding Methods
•
Part 1. Rules for the Installation and Maintenance of
Electric Supply Stations and Equipment
•
Part 2. Safety Rules for the Installation and Maintenance
of Overhead Electric Supply and Communication Lines
•
Part 3. Safety Rules for the Installation and Maintenance
of Underground Electric Supply and Communication Lines
•
Part 4. Work Rules for the Operation of Electric Supply
and Communications Lines and Equipment
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Part 1: Rules for the Installation and Maintenance of
Electric Supply Stations and Equipment
Purpose
Scope
• The purpose of Part 1 is the practical safeguarding of
persons during the installation, operation, or
maintenance of electric supply stations and their
associated equipment.
• Part 1 covers the electric supply conductors and
equipment, along with the associated structural
arrangements in electric supply stations, that are
accessible only to qualified personnel. It also covers the
conductors and equipment employed primarily for the
utilization of electric power when such conductors and
equipment are used by the utility in the exercise of its
function as a utility.
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Part 2: Safety Rules for the Installation and Maintenance
of Overhead Electric Supply and Communication Lines
Purpose
Scope
• The purpose of Part 2 is the practical safeguarding of
persons during the installation, operation, or
maintenance of overhead supply and
communication lines and their associated
equipment.
• Part 2 covers supply and communication
conductors and equipment in overhead lines. It
covers the associated structural arrangements of such
systems and the extension of such systems into
buildings. The rules include requirements for spacing,
clearances, and strength of construction. They do not
cover installations in electric supply stations except as
required by Rule 162A.
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Part 3: Safety Rules for the Installation and
Maintenance of Underground Electric Supply and
Communication Lines
Purpose
Scope
• The purpose of Part 3 is the practical safeguarding of
persons during the installation, operation, or maintenance
of underground or buried supply and
communication cables and associated equipment.
• Part 3 covers supply and communication cables and
equipment in underground or buried systems. The rules
cover the associated structural arrangements and the
extension of such systems into buildings. It also covers
the cables and equipment employed primarily for the
utilization of electric power when such cables and
equipment are used by the utility in the exercise of its
function as a utility. They do not cover installations in
electric supply stations.
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Part 4: Work Rules for the Operation of Electric Supply
and Communications Lines and Equipment
Purpose
Scope
• The purpose of Part 4 is to provide practical work
rules as one of the means of safeguarding
employees and the public from injury. It is not the
intent of these rules to require unreasonable steps to
comply; however, all reasonable steps shall be taken.
• Part 4 covers work rules to be followed in the
installation, operation, and maintenance of electric
supply and communications systems.
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Grounding Methods Overview
• Section 9: Rules for Grounding Methods
• Why are power systems grounded?
• How does grounding power systems improve
safety?
• What are safe, effective, and practical
methods to ground power systems?
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Definition
Effective Ground/Effectively Grounded: Bonded to
an effectively grounded neutral conductor or to a
grounding system designed to minimize hazard to
personnel and having resistances to ground low enough
to permit prompt operation of circuit protective devices.
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Definition
Effectively Grounded Neutral Conductor: A
conductor that is intentionally connected to the source
transformer neutral directly or through an impedance to
limit phase-to-ground fault current and has not less
than four grounds in each 1.6km (1.0 mi) of line. The
conductor shall be of sufficient size to carry the
available fault current and permit prompt operation of
circuit protective devices.
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NESC Rule 96A
Grounding systems shall be designed to minimize
hazard to personnel and shall have resistances to
ground low enough to permit prompt operation of
circuit protective devices. Grounding systems may
consist of buried conductors and grounding electrodes.
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90 Purpose
• Practical methods for grounding to protect
workers and the public from electrical injury
91 Scope
• Not a requirement to ground. Those
requirements are found in other Rules outside
of Section 9.
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92B. Point of Connection Of Grounding
Conductor
•
Alternating Current Systems
•
750V and below
 Ground at the neutral if there is a
neutral

Ground at source and at line side of
all service equipment
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92E. Fences
• Only applies where other parts of NESC
require fences to be grounded
• Designed to Limit:
 Touch potential
 Step potential
 Transferred voltages
• NOTE: See IEEE Std 80 for guidance
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92E. Fences
• Ground fence at each side of gate or other opening
• Bond gates to grounding conductor, jumper, or fence
• Use buried jumper to bond across gate or other fence
opening
• Bond barbed wire to grounding conductor or fence:
• If barbed wire remains tight, OK
• Use suitable connections- Care about copper to steel
• Ground at fence posts if posts are conductive
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94. Grounding Electrodes
•
Two electrode types:
• Existing – such as cold water pipes
•
Made – such as ground rods and other arrangements
like buried wire, strips, or plates
•
Rules recognize different arrangements and materials
(just no aluminum)
•
A qualified engineering study required to have
electrodes not specified
•
Pole butt plates and wire wraps cannot be used for
transformer grounds – Only count as ½ electrode
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96C. Ground Resistance for Multi-Grounded
Systems
• No actual resistance value required.
• Neutral of sufficient capacity to be connected to a
made or existing electrode at:
• Each transformer location
•
And enough other connections to make at least
four connections in EACH mile. Do not count
grounds at individual services
•
Rule can be applied to shield wires grounded at
the source
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96D. Single-Grounded (Unigrounded or
Delta) Systems
• Individual electrodes should not
exceed 25 ohms resistance. If 1st
electrode > 25 ohms, use methods in
Rule 094B
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97C. Four Grounds in Each Mile
•
This means for every way a mile of line can be
created in the circuit there must be at least
four grounds.
•
Cannot use the grounds at meter bases (i.e.,
customer service equipment) in this number
of grounds in each mile.
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99C. Additional Grounding and Bonding
Requirements for Communication
• If communication and supply systems serving
the same structure use separate grounding
electrodes, bond electrodes with #6 copper or
equivalent.
• The change from #14 to #6 copper for
bonding is to avoid building fires if a neutral
becomes disconnected at the structure.
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Electric, Telephone, and Cable Television
Systems are bonded together
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Maintenance of NESC
The NESC is revised every 5 years
• Current edition is 2012, published 1
August 2011
• A fixed schedule for revision is published
• Next edition will be 2017, published 1
August 2016
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Revising the National Electrical Safety
Code
A proposal to revise the NESC may be
prepared by any:
• Substantially interested person
• Interested organization
• NESC Subcommittee
• Member of the NESC Committee or its
subcommittees
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NESC as Regulation
The NESC as written is a voluntary
standard
Some editions and some parts of the Code
have been adopted, with and without
changes, by some state and local
jurisdictional authorities (currently, 49 states
within the U.S.)
To determine the legal status of the NESC in
any particular state or locality within a state,
the authority having jurisdiction should be
contacted
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NESC Interpretations
The NESC has an Interpretations Subcommittee
that has sole and exclusive authority to provide
official interpretations of the text of any edition
of the National Electrical Safety Code
• Interpretations do not change Code text
• Developed through consensus
• Representation on Interpretations Committee
from members with expertise in various
parts of the Code
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NESC 2017 Edition
 Publication date 1 August
2016
 Effective date: 180 days
following publication
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NESC Handbook
 New format: Code rules
and Handbook text
interspersed
 No single author
 IEEE is editor
 New contributors and peer
reviewers for Parts and
Sections
 Publication date 1 August
2016
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Acknowledgements
• U.S. Trade and Development Agency
• American National Standards Institute
• National Electrical Manufacturers Association
• Institute of Electrical and Electronics Engineers
• Eversource Energy
• Gulf Power, A Southern Company
• Sue Vogel, Senior Manager, National Electrical Safety Code,
IEEE Standards Association
• John Dagenhart, President of Dagenhart Consulting Services,
P.C., and Chair of NESC Subcommittee 2, Grounding Methods
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Thank you!
For more information, contact:
Lauren E. Gaunt
Principal Engineer, Eversource Energy
[email protected]
Mark A. Konz
Customer Service Organization Training Supervisor,
Gulf Power Company
[email protected]
Sue Vogel
Senior Manager, NESC & Technical Programs
IEEE Standards Association
[email protected]
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Appendix
• NESC Summit 2015
• NESC Workshop 18 – 19 October 2016
• Other Items in the Works
• Ways to Engage
• Pakistan Adaptation of NESC
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NESC Summit 2015
 An inaugural NESC Summit held in April
• Over 100 attendees, stakeholders
• A/S Pat Hoffman, U.S. DoE, Keynote Speaker
 Resiliency was a major topic
 NESC Visioning Sessions held to address:
• The Future of the NESC
• Design vs. Safety
• The NESC Process
 See NESC Summit presentations at:
http://standards.ieee.org/events/nesc-summit.html
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Outputs from NESC Summit
 A White Paper is available that addresses Visioning topics
http://standards.ieee.org/events/nesc/summit_white
paper.html
 Six NESC videos created at NESC Summit with IEEE.tv
• The NESC®: Perspectives on Resiliency
• The NESC®: Engaging the Next Generation
• The NESC®: Focused on Worker Safety
• The NESC®: A Legacy of Safety
• The NESC® Summit 2015: Department of Energy
Overview: Patricia Hoffman Keynote
• The NESC® Summit 2015: OSHA Overview: Dean
McKenzie Keynote
http://www.standardsuniversity.org/videos/ or
https://www.youtube.com/user/IEEESA (search for NESC)
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Next NESC Event

NESC Workshop
18-19 October 2016
Grand Hyatt San Antonio
San Antonio, TX

1.5-day event

Registration to be launched May 2016

All stakeholders welcome to attend
San Antonio, TX
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NESC Workshop
Topics to include
 2017 NESC Changes
San Antonio, TX
October 18-19
 Kick off the 2022 edition, including issues
relevant to addressing the NESC’s future; e.g.,
• Solar/Large Scale PV, Wind, Energy Storage
• Microgrids
• Interconnection
• Resiliency
• Wind loads
• NESC/NEC collaboration
 A Subcommittee 5 meeting and workshop is planned
for 20 October 2016 in San Antonio—meeting notice
to be issued soon
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Other Items in the Works
•
New comprehensive NESC website
to be launched mid-2016
•
NESC Handbook—Spanish
translation (Handbook text only)
•
NESC/NEC White Paper
Collaborating with NEC key
principals to address gray
areas/jurisdiction between two
Codes
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NESC MOOCs
(Massive Online Open Course)
 Seven MOOCs in development
Overview
2017 Changes
Grounding Methods
Part 1
Part 2
Part 3
Part 4
 NESC members as anchors and
contributors
 Multi-media
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NESC Mobile App
 NESC’s First App
 IT Main Platform has been
selected
 Equations and Tables under
development
 Link to Interpretations webpage
 Projected Release Date:
December 2016
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Ways to Engage
• Attend the NESC Workshop to
help drive the future of the
NESC
• 18-19 October 2016
• San Antonio, TX
• Submit Change Proposals for
the 2022 NESC
• Submit Comments during the
Public Comment Period
• New comprehensive NESC
website to be launched mid2016
• Opt-in for regular updates
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Pakistan Adaption of NESC
 IEEE-SA approached by Pakistan Engineering Council (PEC) in developing "Pakistan
Electric and Telecom Safety Code (PETSAC)” in 2014
– Statutory and accreditation body for engineers
– PEC worked with USAid-PDP, The US Agency for International Development,
Power Distribution Program, to develop a draft document
– Not a straightforward adoption, but an adaption (local conditions, telecom section,
etc.)
IEEE granted a royalty-free license to PEC
– Strongly aligns with IEEE’s mission “for the benefit of humanity”
IEEE-SA and PEC issued a joint press release 11/10/15
– “The Government of Pakistan on 30 July 2015 notified PETSAC-2014 for
implementation by electrical power and telecommunication utilities, both private
and public, across Pakistan, and the code is to be made fully effective within six
months. The Pakistan Engineering Council plans to arrange workshops and
seminars across the country for mass dissemination and publicity of PETSAC2014, which was created with financial assistance from the United States Agency
for International Development (USAID)-Power Distribution Program, Pakistan.“
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PEC comments
“On behalf of Pakistan Engineering Council and USAID-PDP, we are
really grateful for your kind consideration and encouragement for our
efforts to safeguard the workforce and general public from the
accidents/ electrocuting incidents in the electric and telecom sectors in
Pakistan.”
“It is the first national level initiative in our country and would be a
great service for our people.”
”…the subject document [PETSAC]…is a dire need for the people of
Pakistan…”
PEC is pleased to announce Launching of Pakistan Electric and
Telecommunication Safety Code (PETSAC-2014) on 14 December,
2015, 1000 hours at Marriott Hotel, Islamabad, Pakistan.
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