Doble Tutorial - Medium Voltage Power Cables and Accessories

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TUTORIAL:

MEDIUM VOLTAGE POWER CABLES

AND ACCESSORIES

2011 International Conference of Doble Clients

Thursday, March 31, 2011

7:30 AM – 12:00 PM

Westin Copley Place Hotel

America North, 4

th

_Floor

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Doble Client Conference: ICEA Standards Review March 31, 2011

Insulated Cable

Engineers Association

(ICEA)

Standards Review

I. Overview of ICEA

Energy Division – Power Cable Section II. Industry Wide Input & Standards Coordination III. ICEA Cable, Test & Application Standards

That Apply To Power Cables IV. Navigating The ICEA Website

Overview of ICEA ¾Composed strictly of engineers who are employed by

cable manufacturing companies.

¾These companies are sponsors of the association.

¾Members cannot be involved in sales, pricing or order placement. ¾IPCEA was formed in 1925 by a group of power cable engineers.

¾Evolved into 3 separate sections – Control & Instrumentation Cables, Power Cables & Portable Power Cables.

¾In 1979 Communication Cables were added and the name was changed to Insulated Cable Engineers Association (ICEA).

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Overview of ICEA

¾The organization was later reorganized into two Divisions ¾Energy Cables

¾Communications Cables ¾The Energy Cables Division retained

¾Control & Instrumentation (C&I) ¾Power

¾Portable

¾The Communication Cables Division was further subdivided into ¾Copper

¾Fiber

Overview of ICEA

¾The association meets quarterly in March, June, September and December.

¾The association maintains a website at ICEA.net ¾The association is a “Not-For-Profit” organization who’s sole

support is from member dues & fees and standards sales. ¾Since 1925 the objective has been to ensure safe, economical

and efficient cable systems utilizing proven state-of-the-art materials and concepts.

Industry Wide Input & Standards Coordination ¾The Utility Power Cable Standards Technical Advisory Committee

UPCSTAC was formed in 1996.

¾Outgrowth of a long felt need for a comprehensive, national standard for concentric neutral power cable.

¾UPCSTAC membership is comprised of ¾ICEA Power Cable Section members ¾AEIC Cable Engineering Committee members

¾The primary documents covered by UPCSTAC are for Medium and High Voltage Utility Power Cables.

¾The documents are also reviewed by IEEE Insulated Conductors Committee (ICC) and American National Standards Institute (ANSI)

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Cable, Test & Application Standards for Power Cables

Test Standards

Test Standards include:

¾ANSI/ICEA T-24-380 Standard for Partial-Discharge Test Procedure ¾ICEA T-25-425 Guide for Establishing Stability of Volume

Resistivity for Conducting Polymeric Compounds of Power Cables ¾ANSI/ICEA T-26-465 Guide for Frequency of Sampling Extruded

Dielectric Cables

¾ANSI/ICEA T-28-562 Test Method for Measurement of Hot Creep of Polymeric Insulation

¾ANSI/ICEA T-27-581 Test Methods for Extruded Dielectric Cables

Test Standards include: (continued)

¾ANSI/ICEA T-31-610 Test Method for Conducting Longitudinal Water Penetration Resistance Tests on Blocked Conductors ¾ICEA T32-645 Guide for Establishing Compatibility of Sealed

Conductors with Conductor Stress Control Materials ¾ICEA T-33-655 Low Smoke, Halogen-Free Polymeric Jackets ¾ANSI/ICEA T-34-664 Test Method for Conducting Longitudinal Water

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Application Standards

Cable, Test & Applications Standards for Power Cables

Application Oriented Standards include:

¾ANSI/ICEA P-32-382 Short-Circuit Characteristics of Insulated Cable ¾ICEA P-54-440 Ampacities of Cables in Open-Top Trays ¾ANSI/ICEA P-45-482 Short-Circuit Performance of Metallic Shields

& Sheaths

¾ANSI/ICEA P-79-561 Guide for Selecting Aerial Cable Messengers & Lashing Wires

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Non-shielded Cable Standards include:

¾ANSI/ICEA S-76-474 Neutral Supported Power Cable Assemblies with Weather-Resistant Extruded Insulation Rated 600 Volts ¾ANSI/ICEA S-70-547 Weather Resistant Polyethylene Covered

Conductors

¾ANSI/ICEA S-81-570 600 Volt Rated Cables of Ruggedized Design for Direct Burial Installations as Single Conductors or Assemblies of Single Conductors

Non-shielded Cable Standards include: (continued)

¾ANSI/ICEA S-95-658 Non-Shielded Power Cables Rated 2000 V or Less

¾ICEA S-96-659 Non-Shielded Power Cables Rated 2001 – 5000 V ¾ANSI/ICEA S-105-692 600 Volt Single Layer Thermoset Insulated

Utility Underground Distribution Cables

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Shielded Cable Standards include:

¾ANSI/ICEA S-93-639 Shielded Power Cables 5,000 – 46,000 V ¾ANSI/ICEA S-94-649 Concentric Neutral Cables Rated 5 Through

46 kV

¾ANSI/ICEA S-97-682 Utility Shielded Power Cables Rated 5 Through 46 kV

¾ANSI/ICEA S-109-720 Extruded Insulation Power Cables Rated Above 46 kV Through 345 kV

Working Groups for New Standards • WG 684 Performance Based Utility 5 – 46 kV • WG 726 Pellet Inspection Systems • WG 728 Non-Metallic Shielded Mining Cables • WG 733 Tree Wire and Spacer Cable • WG 734 New Electric Distribution Ampacity Tables

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We reorganized the ICEA Web site at http://www.icea.net to make it easier to find the Standard you need.

• Added a “New & Recently Added Documents” Direct Link • Separated Energy & Communication Documents • Divided Energy Documents into:

• Power Cable • Portable Cable

• Control & Instrumentation (C&I) Cable

• Added a Preview & Purchase Link for Each Document • Cover, Table of Contents, Scope

About ICEA

The Insulated Cable Engineers Association (ICEA) is a professional organization dedicated to developing cable standards for the electric power, control, and telecommunications industries. Since 1925, the objective has been to ensure safe, economical, and efficient cable systems utilizing proven state-of-the-art materials and concepts. Now with the proliferation of new materials and cable designs, this mission has gained in importance. ICEA documents are of interest to industry participants worldwide, i.e. cable manufacturers, architects and engineers, utility and manufacturing plant personnel, telecommunication engineers, consultants, and OEM'S.

ICEA is a "Not-For-Profit" association whose members are sponsored by over thirty of North America's leading cable manufacturers. The technical development work is performed in four semi-autonomous Sections; namely, the Power, Control & Instrumentation, Portable, and Communications Cable Sections. In addition there are currently two very active major Technical Advisory Committees, one for Telecommunications Wire and Cable Standards (TWCS TAC) and another Utility Power Cable Standards (UPCS TAC).

INSULATED CABLE ENGINEERS ASSOCIATION, Inc.

ICEA Engineering Documents

It is ICEA's mission to keep these standards up-to-date on a continuing basis. These Documents may be purchased through IHS.

ICEA Standards fall into four categories:

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New & Recently Added Documents

These standards were developed by the Insulated Cable Engineers Association, Inc. (ICEA), within the past 3 years. These Documents may be purchased through IHS.

You may view the first pages including the Table of Contents for some documents by clicking on the Preview Documents link and/or purchase them by clicking on the Purchase Now link. Not all documents have previews available.

Energy Cable Standards ANSI/ICEA T-24-380-2007

Guide For Partial-Discharge Test Procedure $60.00 Preview Document Purchase Now

Energy Documents

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Thanks For Including ICEA

In Your Conference

&

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1

AEIC Cable Engineering

Committee Specifications,

and Guides

by Mike Smalley – We Energies, Chair, AEIC Cable Engineering Committee

Doble Conference – March 31, 2011

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Association of Edison Illuminating

Companies (AEIC)

Established in 1885 by Thomas Edison Members are electric utilities, generation

companies, transmission companies, and distribution companies – internationally.

Through a committee structure, the Association

addresses technological problems associated with planning, building and operating an electric utility system.

AEIC (Cont)

Includes investor-owned, federal, state,

cooperative, and municipal systems

Associate members include organizations

responsible for technical research and for promoting, coordinating, and ensuring the reliability and efficient operation of the bulk power supply system (e.g. EPRI).

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AEIC Committees

The AEIC's six committees are staffed with

experts from management of member

companies and meet regularly during the year to explore issues in their particular areas:

Load Research Meter and Service Power Apparatus Power Delivery Power Generation Cable Engineering

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Cable Engineering Committee (CEC)

28 Members and 2 Technical Advisors

Cable Engineers from Electric Utilities

Engineers from Research Labs and

Organizations

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CEC Purpose

The purpose of the

CEC is to develop and maintain specifications and guides for electric utility cable system design, maintenance, and operations.

7 Specifications 11 Guidelines

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CEC Procedures

Goals:

Reaffirm, Revise, or Withdraw specifications every 5 years

Reaffirm, Revise, or Withdraw guides every 7 years

A Task Group chair, Vice Chair, and TG

members are assigned to each document

Once complete, documents are balloted within

the task group. After TG approval, the whole CEC is balloted

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Outline for All Cable Specs

Conductor Conductor Shield Insulation Insulation Shield Metallic Shielding Moisture Barrier Jacket

Outline for All Cable Specs (Cont)

Cable Identification

Production Test Procedures Shipment and Reels Guarantee

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CEC Paper (Laminar) Cable Specs

These Specifications are considered to be the

industry standard (there is no NEMA, ANSI or ICEA cable standard associated with them):

CS1-90 PILC

CS2-97 High Pressure Pipe Type CS3-90 Low Pressure Gas-Filled Type

CS4-93 Low and Medium Pressure Self-Contained Liquid Filled Cable

CS31-95 Pipe Filling Liquids

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CEC Extruded Dielectric Cable Specs

CS5, Obsolete, replaced by CS8

CS6, Obsolete, replaced by CS8 and CS9 CS7, Obsolete, replaced by CS9

CS8-07 Extruded Dielectric 5-46 kV, supplements:

NEMA WC74/ICEA S-93-639 (Shielded Power Cables 5-46 kV)

ICEA S-94-649 (Medium Voltage CN cables)

ICEA S-97-682 (Utility Shielded Power Cables 5-46 kV)

CS9-06 Extruded Dielectric Cables and Their Accessories Rated Above 46 kV through 345 kV AC, supplements:

ICEA S-108-720 (Extruded Power Cables 46-345 kV)

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CEC Guides

CG1-96 Maximum Temperatures for

Paper-Insulated Cables, use with: CS1 through CS4

CG3-05 Installation of Pipe-Type Cable

Systems, use with: CS2

CG4-97 Installation of Extruded Dielectric

Cables 69-138 kV, use with: CS9

CG5-05 Extruded Power Cable Pulling, use with:

CS8, CS9, ICEA S-81-570, S-95-658, S-94-649, S96-659, S108-720, T-33-655

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CEC Guides (Cont)

CG6-05 Maximum Temperatures of

Extruded Dielectric Cables, use with:

CS8, CS9, S-94-649, S-97-682, S-108-720,

S-93-639

CG7-05 Replacement and Life Extension

of Extruded Dielectric 5-35 kV Cables, use with:

CS8, S-94-649, S-97-682

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CEC Guides (Cont)

CG8-03 Electric Utility Quality Assurance

Program for Extruded Dielectric Cables, use with:

CS8, CS9, S-94-649, S-97-682, S-93-639, S-108-720

CG9-00 Installing, Operating, and Maintaining

Lead Covered Cables 5-46 kV, use with: CS1, CS2, CS3, CS4, and CS8

CG10-02 Developing Specs for Extruded Cables

5-46 kV, use with: CS8

CEC Guides (Cont)

CG11-02 Reduced Diameter Extruded

Dielectric Cables 5-46 kV, use with:

CS8, S-94-649, S-97-682, S-XX-684 (future)

CG12-05 Minimizing the Cost of Extruded

Dielectric Cables 5-46 kV

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CS1-90 PILC Cable

Specification for Impregnated Paper-Insulated Metallic-Sheathed Cable, Solid-Type 11th Edition, October 1990 Revision in progress 17

CS1-90 Scope

This specification applies to impregnated

paper-insulated, metallic-sheathed cable of the "solid" type which is to be used for the transmission and distribution of electrical energy on electric utility systems.

Cables Rated 1 kV to 69 kV

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CS1-90 Scope

The term solid-type cable designates a

hermetically sealed type of mass-impregnated cable having an essentially solid cross-section impregnated with a saturant of suitable viscosity, and

designed for operation without a pressure medium.

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CS2-97 High Pressure Pipe-Type

Cable

Specification for

Impregnated Paper and Laminated Paper Polypropylene Cable, High Pressure Pipe-Type

6th Edition, March 1997

Revision in progress

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CS3-90 Low Pressure Gas Filled

Cable

Specification for

Impregnated Paper Insulated Metallic Sheathed Cable, Low Pressure Gas Filled-Type

3th Edition, October 1990 Revision in progress

CS4-93 Self Contained Liquid

Filled Cable

Specification for

Low and Medium pressure SCLF cable 8th Edition, January 1993 Revision in progress

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CS8-07 Extruded Cable 5-46 kV

Specification for Extruded Dielectric,

Shielded Power Cables Rated 5 Through 46 kV

3rdEdition, February 2007 34 pages

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CS8-07 Scope

Supplements ANSI/ICEA S-94-649 and

S-97-682

This specification covers cables rated

5-46 kV, which are used for the distribution of electric energy on electric utility systems.

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CS8-07 Additional Items

Qualification Tests Appendixes

Industry Specifications, Standards, and References

History of Cable Diameters

Procedure for Determining Diameters of Cables

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CS8-07 Additional Items

Partially replaced CS5 and CS6 (covers both

EPR and XLPE/TRXLPE cables):

CS5 covered XLPE insulated cables from 5-46 kV Originally published: 1969

CS6 covered EPR insulated cables from 5-69 kV

Originally published: 1972

ANSI/ICEA standards have provided a way to

greatly simplify the AEIC specifications.

The 2007 version largely adopted ICEA cable

diameters; which use lower minimum point thicknesses... Example next page->

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Insulation Thickness Comparisons

175-mil average (previous AEIC)

158 190

176

min max

Insulation Thickness Comparisons

min-max (ANSI/ICEA)

165 205

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Example

Install two joints and a short piece of new

cable into section of failed old cable

Both cables 1000 kcmil 260 mil 25 kV Old cable manufactured in 1979 to AEIC

CS5-79 Specification

New cable manufactured to ANSI/ICEA

Standard

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CS8-00 Ranges of 1000 kcmil 25

kV Cable and Three Joints

1660 160 1665 120 1515 265 1645 95 1710 60 1500 1550 1600 1650 1700 1750 1800 1850 Diameter in mils Z Y X ANSI/ICEA AEIC 30

CS8-07 Some Differences from 649

Includes “Guarantee” section Includes Field Strippability Test Shipment and Reels

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CS9-06 Extruded Cables and

Accessories rated 46-345 kV

Specification for Extruded Insulation

Power Cables and their Accessories rated above 46 kV Through 345 kV AC

1stEdition, December 2006 64 pages

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CS9-06 Background Info.

Partially replaced CS6 and CS7:

CS6 Covered EPR insulated cables from 5-69 kV

CS7 covered XLPE insulated cables from 69-138 kV

The first AEIC specification covering a complete cable system including joints/terminations

Covers both EPR and XLPE/TRXLPE cable systems A system specification, not just a cable standard Some differences from S-108-720 in conductor shield

material and in the number and size of voids in the insulation

CS9-06 Contents

General Cables Terminations Joints

Sheath Bonding/Grounding Systems, Link Boxes, and SVL’s

Qualification Tests on System Prequalification Tests on System Electrical System Test After Installation Quality Assurance

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CEC Guidelines

In the early days of the cable industry, no

other guidelines were available within the industry concerning cable operations, installation, and maintenance.

CEC decided to begin developing some

guidelines for utilities to use.

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Temperature Guides CG1 and CG6

CG1 – PILC Cables

CG6 – Extruded Dielectric Cables

Emergency Operations and Temperature

Limits

Principles and Basic Background Factors Limiting Factors

Determination of Ampacity

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CG1-07 PILC Temperatures

Guide for Establishing the Maximum

Operating Temperatures of Impregnated-Paper- and Laminated-Impregnated-Paper-

Laminated-Paper-Polypropylene-Insulated Cable

4thEdition, June 2007

Scope: Operating temperature limits for

transmission and distribution paper and paper-polypropylene insulated cable.

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CG6-05 Extruded Cable

Temperatures

Guide for Establishing the Maximum

Operating Temperatures of Extruded Dielectric Insulated Shielded Power Cables

2nd_{Edition, November 2005}

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CG6-05 Scope

This guide primarily covers temperatures

limits for extruded dielectric cable in underground installations.

Some guidance is provided for other

applications such as aerial installations and riser pole applications.

CG5-05 Extruded Cable Pulling

Underground Extruded Power Cable

Pulling Guide

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CG5-05 Scope

Outlines the pulling parameters that need

to be considered when installing underground power cable in duct.

Based on EPRI Project EL-3333

“Maximum Safe Pulling Lengths for Solid Dielectric Insulated Cables”

Some sidewall pressure and tension

recommendations differ from those of cable manufacturers

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CG5-05 Scope (Cont)

Pulling guides and computer software are

available from many cable manufacturers and lubricant manufacturers.

Several of these guides provide a basic

introduction to cable pulling criteria.

Some of these manufacturers’ guides are

listed in the bibliography.

CG5 is intended to complement these

publications.

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CG5-05 Scope (Cont)

The major points covered in the guide

include:

Factors that influence pulling tensions such as

cable type, conduit type and size, lubricants, and installation practices

Calculation of maximum pulling lengths

allowable without damaging the cable

Limits on cable tension and sidewall bearing pressure

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CG5-05 Contents

Cable Removal

Economic Considerations

Design Criteria and Pulling Limits Pulling Tension Formulae

Sidewall Bearing Pressure Formulae Sample Calculations

References

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CG7-05 Extruded Cable

Replacement 5-35 kV

Guide for Replacement and Life Extension

of Extruded Dielectric 5-35 KV Underground Distribution Cables

2ndEdition, November 2005

CG7-05 Scope

Covers extruded dielectric utility

distribution system cables rated 5-46 kV

Includes options for cable replacement

and cable life extension based upon current options within the industry today.

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CG7-05 Contents

Identifying Problem Cable Systems Decision Making Tools

Selection and Implementation of Solution

or Corrective Action

Reliability and System Enhancements to

Reduce Cable Failures

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CG8-10 Quality Assurance

Extruded Cables 5-46 kV

Guide for Electric Utility Quality Assurance

Program for Extruded Dielectric Power Cables

3rdEdition, August 2010

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CG8-10 Scope

Techniques and procedures that an

electric utility may use to establish a quality assurance program for extruded dielectric power cable

Helps to ensure that the utility consistently

receives cable with the characteristics it desires

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CG8-10 Contents

The Utility Cable Specification Manufacturing Plant Audits Cable Inspection and Testing Keeping Records of Installation and

Operating Experiences

Outline of a Cable Specification Manufacturer Questionnaire Inspection List

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CG9-00 Installing and Operating

Lead Covered Cable 5-46 kV

Guide for Installing, Operating, and

Maintaining Lead Covered Cable Systems Rated 5 kV Through 46 kV

1stEdition, May 2000 Reaffirmed in 2008

CG9-00 Scope

Lead-covered cables have been in use for

over 80 years and have demonstrated exceptional service reliability.

Two of the most common constructions in

use are paper-insulated lead-covered cable (PILC) and lead-covered extruded-dielectric cable.

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CG9-00 Scope (Cont)

Dealing with the lead on these types of

cables has become costly due to Federal and State safety regulations.

Consequently, the use of lead covered

cables has declined and the expertise needed to install and maintain them has declined as well.

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CG9-00 Scope (Cont)

This guide is intended to outline generally

accepted installation, operation, and maintenance practices for lead covered cables.

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CG9-00 Contents

Manholes Cable Handling

Cable Installation in Duct and Direct Buried Cable Accessories (Joints and Terminations) Grounding

Identification and Installation Records Inspection and Maintenance

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55

CG10-10 Developing Specs for

Extruded Power Cables 5-46 kV

Guide for Developing Specifications for

Extruded Power Cables Rated 5 through 46 kV

2ndEdition, December 2010

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CG10-10 Scope

This guide describes the various choices

that an engineer must consider when developing a medium voltage (5-46 kV) cable specification for utility use.

It is designed to acquaint the user with

those criteria necessary to ensure the cable will perform as intended.

CG10-02 Contents

The contents of CG10 basically follows the

outline of CS8 (MV Cable Spec) and CS9 (HV Cable Spec)

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CG11-02 Reduced Diameter

Extruded Dielectric Cables 5-46 kV

Guide for Reduced Diameter Extruded

Dielectric Shielded Power Cables Rated 5 Through 46 kV

1stEdition, January 2002

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CG11-02 Scope

Replacing smaller PILC cables in existing,

space-limited infrastructure.

Provides general information to be used

when specifying and using cables with reduced diameters. 60

CG11-02 Contents

Design Variables Jacket Metallic Shield (Flat Strap or Longitudinally Corrugated Tape) Insulation Shield Insulation Conductor Shield Center Conductor

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CG11-02 Contents (Cont)

Operating Conditions

Maximum Conductor Temperatures

Emergency Operating Temperatures Metallic Shield Short Circuit Rating Ampacity Requirements 62

CG11-02 Contents (Cont)

Field Considerations Duct Clearances Duct Configurations Terminations and Joints Pulling Methods

Cable Handling Proof Testing

CG12-05 Minimizing the Cost of

Extruded Cables 5-46 kV

Guide for Minimizing the Cost of Extruded

Dielectric Shielded Power Cables Rated 5 through 46 kV

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CG12-05 Scope

This guide provides general information

that can be used to minimize the initial purchase cost of extruded dielectric cable rated 5-46 kV.

The variables allow the user to be aware of

some options to consider when attempting to reduce the initial purchase cost of their cable. 65

CG12-05 Contents

Design Variables Jacket Metallic Shield (Concentric Neutral or Tape Shield) Insulation Shield (Semicon) Insulation Conductor Shield Center Conductor (Strand-filled) 66

CG12-05 Contents (Cont)

Labeling Packaging Production Tests

Quality Assurance Documentation Qualification Tests

Industry Specifications, Standards,

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Conclusions

Standards and Specifications affect every aspect of

how we design our cable systems.

Many Standards and Specifications are

interrelated.

Individual Company specifications should

coordinate with these industry standards for an optimal cable system design.

Industry Guides may be used to gain greater insight

into the application of the cable system

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Standards, Specs, and Codes

A technical standard is an established

norm or requirement. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes, and practices.

A specification is an explicit set of

requirements to be satisfied by a material, product, or service

Wikipedia.org

Standards, Specs, and Codes (Cont)

Codes are rules established or adopted by

a governmental agency, required to be followed. Codes represent the minimum acceptable requirements.

Governmental agencies usually obtain

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Standards and Specifications

Affecting Cable Systems

American National Standards Institute

(ANSI)

ASTM International (ASTM)

Institute of Electrical and Electronics

Engineers (IEEE)

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Standards and Specifications

Affecting Cables

International Electrotechnical Commission

(IEC)

Insulated Cable Engineers Association

(ICEA)

Association of Edison Illuminating

Companies (AEIC)

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Codes Affecting Cables and

Systems

National Electrical Code (NEC)

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Codes Affecting Cables and

Systems

Code of Federal Regulations

Operating requirements

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American National Standards

Institute (ANSI)

Established in 1918 by 5 engineering

societies and 3 government organizations

Composed of volunteer member

companies

ANSI Scope

ANSI oversees the development of

voluntary consensus standards for products, services, and processes in the United States.

ANSI also coordinates U.S. standards with

international standards so that American products can be used worldwide.

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ANSI Scope (Cont)

Accreditation by ANSI signifies that the

procedures used by the standards body in connection with the development of American National Standards meet the Institute’s essential requirements for openness, balance, consensus, and due process.

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ANSI Standards for Cable

ANSI/IEEE 386 – IEEE Standard for

Separable Insulated Connector Systems for Power Distribution Systems above 600 V

ANSI C119.4 – Standard for Electric

Connectors

Connectors Used Between Conductors

Aluminum-to-Aluminum or Aluminum-to-Copper

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ASTM International (ASTM)

Originally known as American Society for

Testing and Materials

Uses a Consensus Process

From http://en.wikipedia.org/

Consensus Process – “A group decision making process that not only seeks the agreement of most participants, but also the resolution or mitigation of minority objections.”

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ASTM Publication Types

Standard Specification, that defines the

requirements to be satisfied by the subject of the standard.

Standard Test Method, that defines the

way a test is performed. The result of the test may be used to assess compliance with a Specification.

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ASTM Publication Types (Cont)

Standard Practice, that defines a

sequence of operations that, unlike a test, does not produce a result.

Standard Guide, that provides an

organized collection of information or series of options that does not recommend a specific course of action.

ASTM Standards for Cable

ASTM B 230 – Standard Specification for

Aluminum 1350-H19 Wire for Electrical Purposes

ASTM B 8 – Standard Specification for

Concentric-Lay-Stranded Copper Conductors, Hard, Medium-Hard, or Soft

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Institute of Electrical and Electronic

Engineers (IEEE)

The IEEE is an international non-profit,

professional organization for the advancement of technology related to electricity.

It has the most members of any technical

professional organization in the world, with more than 365,000 members in around 150 countries.

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IEEE Background

IEEE was formed in 1963

Power and Energy Society (PES)

(Formerly Power Engineering Society)

Main group of the IEEE PES that develops

standards for cables and accessories is the Insulated Conductors Committee (ICC)

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IEEE Standards and Guides (ICC)

Develops and Maintains Standards and

Guides for Cables Systems and Accessories:

IEEE Std 386 – Separable Connectors IEEE Std 404 – Cable Joints

IEEE Std 48 – Cable Terminations IEEE Std 400 (and associated point

documents) – Diagnostic Testing in the Field

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National Electrical Code (NEC)

NEC 2008, NFPA 70

90.2 Scope (B) Not Covered – (5)

“Installations under the exclusive control of an electric utility where such installations…

b. Are located in legally established easements

or rights-of-way designated by or recognized by public service commissions, utility

commissions, or other regulatory agencies having jurisdiction for such installations....”

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NEC (Cont)

The NEC does not have jurisdiction over

utilities.

However, the NESC does have jurisdiction

over utilities.

National Electrical Safety Code (NESC)

Work began on the

NESC in 1913 at the National Bureau of Standards (NBS) As NBS Handbooks The 4thedition (1927) is shown here.

ANSI gets approval

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NESC (Cont)

IEEE C2 (IEEE is the

secretariat)

Recognized by ANSI Adopted as law by

most states within the US as the binding code for electrical power systems.

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NESC (Cont)

“…Applicable to the systems operated by

utilities, or similar systems and equipment of an industrial establishment or complex under the control of qualified persons.”

NESC Abstract, 2007 Edition

Part 3 – Safety Rules for the Installation and

Maintenance of Underground Electric Supply and Communication Lines

Section 33 Supply Cable Section 35 Direct-buried Cable

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International Electrotechnical

Commission (IEC)

The IEC is a not-for-profit,

non-governmental international standards organization that prepares and publishes international standards for all electrical, electronic, and related technologies

Instrumental in developing the International

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IEC (Cont)

ANSI is represented on the IEC through

the US National Committee

IEC Technical Committee 20 is

responsible for Electric Cables

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IEC Cable Standards

IEC 60502 – Power cables with extruded

insulation and their accessories for rated voltages from 1 kV up to 30 kV

insulation and their accessories for rated voltages above 30 kV up to 150 kV - Test methods and requirements

IEC Cable Standards (Cont)

insulation and their accessories for rated voltages above 150 kV up to 500 kV

IEC 60287 – Calculation of the continuous

current rating of cables

IEC 60228 – Conductors of insulated

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Insulated Cable Engineers

Association (ICEA)

The ICEA is an organization that develops

standards for electric power, control, telecommunications, and portable cables

Established in 1925 Not-For-Profit association

Members are sponsored by about thirty

North American cable manufacturers

Works with cables only – not accessories.

95

ICEA Document Types

Publications or Guides

ICEA P-32-382-2007 Short-Circuit Characteristics of Insulated Cable Test Methods

ANSI/ICEA T-31-610-2007 Test Method for

Conducting a Longitudinal Water Penetration Resistance Test on Blocked Conductors Standards

ANSI/ICEA S-94-649-2004 Concentric Neutral

Cables Rated 5 Through 46 kV

96

ICEA MV Cable Standards for

Utilities

ANSI/ICEA S-94-649-2004 Concentric

Neutral Cables Rated 5 Through 46 kV

ANSI/ICEA S-97-682-2007 Utility Shielded

Power Cables Rated 5 Through 46 kV

ANSI/ICEA S-108-720-2004 Extruded

Insulation Power Cables Rated Above 46 Through 345 kV

(45)

Medium Voltage Cable

Overview

Manufacturing, Testing, Cable

Prep and Installation

Doble Tutorial, Boston

March 31, 2011

Background

Joe Zimnoch Jr

• Sr Applications Engineer- Okonite

• 27 years

– 8 Years in HV Lab

– Remainder in Application Engineering

Cable Design - Components

• Conductor

• Semiconducting Strand Screen • Insulation

• Semiconducting Insulation Screen • Metallic Shield

• Protective Covering – Jacket / Armor

Conductors -Purpose

• To provide a low resistance path for the flow of current such that the

(1) cable’s temperature ratings are not exceeded

(2) voltage regulation (drop) is within acceptable limits

In other words, why do we

have different conductor sizes?

Conductors

• Conductivity 100% Copper 61% Aluminum 16.6% Steel 15% Tin 8% Lead 108% Silver • Shapes – Class B

Conductor Terminology

What are MCM and kcmil ? • Answer: Thousands of circular mils

• M and k: M = Roman Numeral; MKS abbreviation for thousand • 1 mil = 0.001” (¼” = 0.25” = 250 mils; 1” = 1000 mils) • CM and cmil = circular mil (area of a circle w/o ח) • If Area (sq in.) = ח r2

• Then 1 circular mil = D2_{(diameter of wire in mils squared)}

• Example

Thus for a solid #10 awg wire

– Diameter = 0.1019” or 101.9 mils – CM area = (101.9)2_{= 10,380 circular mils}

(46)

CMA Calculation for 500 MCM Conductor For a 500 mcm (class B – 37 x 0.1162”)

Diameter of = 0.1162” or 116.2 mils

area of 1X = (116.2 mils)2_{= 13,502 circular mils} (13,502 circular mils) x (37) = ~500,000 circular mils 500,000 circular mils = 500 mcm (or kcmil) For a 500 mcm (class I – 1225 x 0.0201”)

Diameter of = 0.0201” or 20.1 mils area of 1X = (20.1 mils)2_{= 404 circular mils} (404 circular mils) x (1225) = ~500,000 circular mils 500,000 circular mils = 500 mcm (or kcmil)

Conductors - Classes

500 mcm

Class B – 37 wires (116.2 mils/wire)

Class C – 61 wires (90.5 mils/wire)

Class H – 427 wires (34.2 mils/wire)

Class I – 1225 wires (20.1 mils/wire)

EHB Excerpt, P. 1, Table 1.1

Conductor Size

Circular Mil Area (circular mils) #1 83,690 1/0 105,600 4/0 211,600 250 mcm 250,000 500 mcm 500,000

Conductors – Class B

1 1 + 6 = 7 1 + 6 + 12 = 19 1x, 7x, 19x, 37x, 61x, 91x, 127x, etc… 7 wires #24-#2 19 wires #1 – 4/0 37 wires 250-500 mcm 61 wires 750-1000 mcm

Conductors: Stranding – Class B

Class B Conductor Stranding Types

500 mcm (37 strand) Diameters Differences

0.813” 0.788” 0.736”

(-3%) (-10%) All three have the SAME cross sectional area

(47)

Class B Conductor Stranding

Types

Cross sectional area of each conductor

500 kcmil 500 kcmil 500 kcmil

All three have the SAME cross sectional area i.e. all are 500 kcmil. The main difference is that the concentric has a large amount of space between the individual strands that is not accounted for in the cross section area calculation. Conversely the compact round conductor has very little trapped area between the strand

Trapped air _{NO Trapped}

air

Compressed, Compact & Flex

Flex

Compressed

Compact

Round, C/R

Rope Strand

• 350 kcmil • 37 Ropes • 24 wires/rope • 37x34=888 wires total • 1 wire OD=20 mils • 202_{= 400 cm/wire} • 400 x 888=355 kcmil

Compact vs. Compressed

in a Connector

• When compressed into the same size connector, both the compact conductor

AND compressed look almost identical

since they both have the same cross sectional area (the area is based on the area of EACH individual strand times the number of strands.

• The cross sectional area is NOT based on

the

overall diameter

of the conductor.

500 mcm connector:

•1 compressed conductor in one side

•1 compact round conductor in the other side.

They were then crimped using 500 mcm

die and then cut across the crimps

(48)

Conductor A - crimped in 500

mcm connector

Conductor B - crimped in 500

mcm connector

Which is compact? A or B?

A=Compact Conductor B=Compressed Conductor

A=Compact Conductor (notice SQUARED strands

on left side of picture)

B=Compressed Conductor (notice ROUNDED strands

on left side of picture)

400 mcm vs. 500 Connector

500 mcm 400 mcm Diff Length 3.53” 3.00” -0.53” OD 1.06” 0.965 -0.095” ID 0.841” 0.767” -0.074” Wall 0.110” 0.100” -0.010 500 mcm c/r OD = 0.736”

(49)

Why?

• Connectors are designed based on compression ratio.

• The compression ratio is the area of the conductor (not counting the air gaps between

the strands) and the area of the connector

before and after the crimp.

• The area of the conductor (again not counting

the air gaps between the strands) is the same

for both the compressed and compact conductor.

Connectors for

Pre-Molded Accessories

( Elbows, Tee-Bodies, Splices, etc)

• Shorter crimp length • Heavy wall of rubber

–Use connector/lug per

manufacturers recommendation

.

Wire Drawing - Mechanical forming

by tension through a die.

5/16"ROD SLIGHTLY SMALLER WIRE

TUNGSTAN CARBIDE DIE

PULL DIRECTION

American Wire Gauge (AWG)

• In order to make a # 10 awg wire from

a 5/16” Cu or Al rod, the rod must be

drawn through - 10 die.

• Likewise, a #24 awg must go through

-24 die.

American Wire Gauge (AWG)

• Industry standard for electrical wire. • Based on 40 sizes between #36 and 4/0. • OD of a 4/0 = 0.46” (~ 0.50”)

• OD of a #36 = 0.0050”

• Using geometric progression, the ratio OD diameters is:

(50)

The End Result

• A #10 awg has:

– OD = 0.10”

– Area = 10, 380 circular mils – DC Resistance = 1 ohm/mft (copper) – Weight = 10 π (or 31.4 lbs/mft)

• Increasing or decreasing 10 awg sizes changes the area, resistance and weight by a factor of 10.

–#10 to #20

–10, 380 to 1,020 cm –0.999 to 10.1 ohms/mft –31.4 to 3.1 lbs/mft

The Not’s

You can determine the OD of 40 different sizes from a #36 up to a 4/0. Using:

To determine the the OD of a #24, substitute 24 for n; likewise for a #1, n = 1.

In order to determine the next larger size above #1 (remember there are 40 sizes) n = 0 (Or 1 zero aka 1/0).

Now for a 2/0 substitute n = -1, for 3/0 n = -2 and for 4/0 n = -3.

Calling the sizes -1,-2 and -3 does not play well, so they are are called 1/0, 2/0, etc..

Not

• Not - Function: adverb Etymology: Middle English, alteration of nought, from nought, • 1 —used as a function word to make negative

a group of words or a word

• 2 —used as a function word to stand for the negative of a preceding group of words <is sometimes hard to see and sometimes not>

An increase of 1 AWG size → 12.3% OD increase → 26.1% Area increase ↑ # 2 to #1 (solid) → 257.6 mils * 1.123 = 289.3 → 66,360 cm * 1.261 = 83,680

AWG Trivia

An increase of 2 AWG sizes → 26.1% OD increase → 59 % Area increase

↑ #14 to #12 (solid) → 64.1 mils * 1.261 = 80.8 → 4110 cm * 1.59 = 6,535 An increase in 2 AWG sized yields ~60% weight increase.

For example a #12 weighs 20.1 lbs/mft versus 12.66 for a #14. Romex, 250 ft - 14/2 w/g $55

Romex, 250 ft - 12/2 w/g $84

(51)

5000 lbs coils (bales) of 1/4” aluminum rod in Santa Maris, C 5/16” copper rod being paid off.

(52)

Empty shop reel (bobbin) being loaded w/drawn wire. Bobbins loaded w/drawn wire. Approx 600 lbs of wire per bobbin.

A #14 wires exits the drawing process at approx 4000 ft/minute.

One wire fed into front of strander •6 wires spun around 1

•12 wires spun around 7 •etc..

Bobbin

loaded

onto head.

(53)

Wires being spun around center wire(s). Close up of 6 wires being spun around center wire at closing die.

Close up of 18 wires being spun around center 19 wires.

Corona or Partial Discharge

In Air

A partial arc or discharge to moisture, dust, or grounded areas. In a Cable

Discharge that can occur off the conductor (sharp points), between layers, at a void or contaminate and at the shield.

(54)

Corona Likes Sharp Points

Corona discharge off sharp points at 500 kV-AC. Used to draw voltage upwards away from grounded base of pothead.

800 kV AC

Transformer

Connected

to 230 kV

Pipe Cable

in 500 kV

Lab

Potheads.

Conductor, Conductor Screen, Insulation, Insulation Screen, Shield/Neutral, Jacket

Insulation and Screens

Insulation Screen

EPR or XLPE

Insulation

Conductor Screen

Discharge-Free vs. Discharge Resistant

Discharge-Free Discharge Resistant

Okonite Company X Company A Company B Company C Company D Company J Company F Company G Company H Company M Company J Vulcanizing Curing Cross-linking (XL) All are equal terms:

to convert a rubber or plastic compound into a “Thermoset” state

(55)

Over Cooked Spaghetti Analogy

Thermoplastic

• Can be melted back to liquid

• Fair deformation resistance (memory) • Limited temperature rating (75C)

Thermoset

• Cannot be melted back to liquid

• Excellent deformation resistance (memory) • Higher temperature rating (90C to 105C)

Thermoplastic

Melts back to its

original liquid form

Thermoset burns

but never reverts

back to its

original liquid form

Insulation – Typical Materials

Thermoset

• Ethylene Propylene Rubber (EPR) • Crosslinked Polyethylene (XLPE)

• Tree Retardant Crosslinked Polyethylene (TR-XLPE)

Thermoplastic • Polyethylene (PE) • Polyvinyl Chloride (PVC) • PVC/Nylon

Insulation – Thicknesses

Voltage Rating _{100 %} _133% 5 kV (shielded) 90 mils 115 mils 15 kV 175 mils 220 mils 25 kV 260 mils 345 mils 35 kV 345 mils 420 mils

Insulation – Thicknesses

100 % 133 % 173% Relay Clears < 1min. Relay Clears < 1hour Indefinite For 3 phase systems For 3 phase systems

For delta systems where one phase may be indefinitely

(56)

133% and 173% Insul Level

Protects Un-faulted Cables

when One Fails

• When one cable fails, the voltage on the two un-faulted cables may increase from 133 to 173% of the phase-to-ground voltage. • Depends if Wye or Delta and how balanced

the loads are.

Fault

Extrusion

• Deformation process.

• Shaping by pushing material through a die.

RAM

DIE CYLINDER

LIQUID METAL, RUBBER, ETC..

EXTRUDED ROD, BAR, ANGLE, ETC..

Four Types of CV Tubes

(57)

ORANGEBURG MANUFACTURING

• CV Extrusion equipment located in peak of roof • CV curing tube runs length of building

CV Curing Tube CV Equipment

• CV Extrusion equipment located in peak of roof

Continuous Vulcanization (CV) Extrusion

(58)

CV Curing Tube Curved to Accommodate Catenary Shape of Cable

• Finished Cable Core:

• Conductor • Conductor Screen • Insulation • Insulation Screen

Why is a Shield Needed?

• Controls stresses within the insulation

– Permits thinner insulation

• Confines field within shield

– No potential on surface of cable

• Controls discharge to ground

• Above 2000 volts is when the above

becomes apparent.

(59)

5 kV NS at 4160 volts

The 2005 NEC reduced rating from 5 to 2.4 kV for NS Also completely eliminated 8 kV NS cables

Discharge from phase-to-phase

5 kV NS at 4160 volts

Discharge

from

phase-to-phase

and

phase-to-ground

Shielding

• Confines the electrical field within the insulation. • Reduces the chance of electrical shock

• Provides a symmetrical distribution of stress • Prevents surface discharge

• Reduces electrical interference • Monitor voltage

• Provides a path for fault currents

• Can be used as a neutral

• Can affect ampacity rating (circulating current)

Factors to Consider for Shield Design

• Fault current capability

• Use as neutral (single phase or 3 phase) • Shield voltage (single point grounding) • Shield circulating current (multi-point grdg)

and its effect on ampacity

• Flexibility and minimum bending radius • Ease of making ground connections

Effect of Fault Current in

Shield on Jacket

• Fault current returning to ground on the shield will produce higher than normal heat.

• Excessive heat can melt the overlying jacket.

• A lower the resistance shield, produces less heat.

(60)

Copper Tape Shield

Wire Shield or Concentric Neutral

Copper Tape and Wires

Longitudinally Copper Shield (LCS)

Flat Copper Straps

(61)

Single Conductor w/Armor

Shield Fault Current Capability

Shield Design Circular Mil Area (CM) Fault Capability -10 cycles (kA) 5 Cu Tape, 12.5% lap 18,974 3.22 5 Cu Tape, 25% lap 20,494 3.48 5 Cu Tape, 50% lap 25,100 4.26 5 Cu LCS, ¼” overlap 31,000 5.26 6 x 20 x 175 Cu Straps 26,738 4.54 16 x 35 x 200 CS (90% Coverage) 32,870 5.58 11 x #14 wires (1/3rd_{N for 2/0 Cu)} _45,197 _7.67 18 x #14 wires (1/3rd_{N for 350 Al)} _73,959 _12.55 5 Cu Tape, 12.5% lap/Al Armor 103,423 17.55 0.095” Lead Sheath 511,100 86.74 1.25” core OD, thermoplastic jacket (constant=0.288) Per Okonite EHB, Page 15

Shielding – Types, Listed from

High Resistance to Low

• Flat copper tape (High Resistance)

• Longitudinally corrugated tape

(LCS) copper or bronze tape

• Concentric Cu wires & Flat Straps

• 1/C Al. Armor-CLX

• Lead sheath (Low Resistance)

Shielding Resistance dictates amt of circulating current

GRAPHIC OF SINGLE POINT GROUND

a.k.a – open circuited shield

CONDUCTOR SHIELD DISTANCE SHIELD VOLTS 25 to 100 V CURRENT FLOW MAGNETIC FIELD

Leakage I thru Insul is shunted to grd via shield. Current thru shield resistance produces voltage.

GRAPHIC OF MULTI-POINT

GROUND

CONDUCTOR SHIELD SHIELD VOLTS 0 V

TRANSFORMER EFFECT OF

MULTI-POINT GROUND

CONDUCTOR SHIELD SHIELD CONDUCTOR

(62)

Shield Circulating Current

• When multi-point grounded acts like a transformer.

• The lower the shield R, the closer we approach 1:1.

• If the shield R is ½ of the conductor

resistance, theoretically as much as 50% of the load current may circulate on the shield.

Concentric Neutral (Shield)

• Acts as both a neutral and a shield.

• Concentric wires return phase current

– Full neutral for single phase (2/C

Cable)

– 1/3rd_{neutral for three phase}

Concentric Neutral (Shield)

• Acts as both a neutral and a shield.

• Concentric wires return phase current

– Full neutral for single phase (2/C Cable) – 1/3rd_{neutral for three phase (return current}

120° out of phase). 1/0 AWG AL 1/0 AWG AL 16 x #14 WIRES -EQUAL TO 1/0 AL 11 x #14 WIRES - EQUAL TO 1/3RD OF A 4/0 AL SINGLE PHASE 1/0 ALUM ANY VOLTAGE THREE PHASE 4/0 ALUM ANY VOLTAGE 4/0

Scenario D (grounded at ONE point)

1-1/C 500 kcmil Cu, 220 Okoguard, 1/3rd_{Neutral Cables per 3”} duct, 3 ducts 7.5” on center

Ampacity = 583 amps Losses = 29.16 watts/ft total

Scenario E (grounded multiple points)

1-1/C 500 kcmil Cu, 220 Okoguard, 1/3rd_Neutral Cables per 3” duct, 3 ducts 7.5” OC, Ampacity = 424 amps Losses = 31.19 watts/ft total Ampacity Comparison

Single Point vs. Multi-point

Grounding

Scenario A (3-1/C’s per Duct)

3-1/C 500 kcmil Cu, 220 Okoguard, 1/3rd_{Neutral Cables} Ampacity = 449 amps

Losses = 25.47 watts/ft total

Scenario E (1/C per Duct)

1-1/C 500 kcmil Cu, 220 Okoguard, 1/3rdNeutral Cables per 3” duct, 3 ducts 7.5” OC

Ampacity = 424 amps Losses = 31.19 watts/ft total Ampacity Comparison

1/C per Duct vs. 3-1/C’s per Duct

(Both Multi-point grounded)

15 kV, Aluminum Condr, URD, Direct Buried, 1 Ckt, Conductor

Size

Triangular Config Flat Spcd Config 75% LF 100% LF 75% LF 100% LF 1/0 (1/3) 207 187 231 206 4/0 (1/3) 308 276 340 301 350 (1/3) 405 362 430 376 500 (1/3) 488 432 499 431 750 (1/3) 593 521 578 494 1000 (1/6) 698 609 666 570

Soil=90 RHO, 90C Condr, 25C Soil Comparison Triangular & Flat Spaced Configuration

Use Flat Spacing for Small Conductor Installations

Source :

NRE

C

(63)

Shield/Neutral Summary

• Controls voltage stress in the insulation. • Some shields can also be used as a neutral. • Multi-point grounding recommended to

reduce shield voltage and for safety. • Shield must also be designed to carry the

available phase-to-ground fault current • The more copper in the shield, the greater

the circulating current depending on the physical arrangement and load current.

Jackets

• Cable Jacket – Nonmetallic Outer Covering of a Cable

• Two Broad Categories: Thermoset and Thermoplastic

• For each application, the operating temperature and environment must be considered

Jacket – Desired Characteristics

• PHYSICAL • CHEMICAL • TEMPERATURE • MOISTURE • AGING • FLAME • SMOKE

Types of Cable Jackets

Thermoplastic

– PE (Polyethylene HD, MD, LD, LLD) – PP (Polypropylene aka living hinge) – PVC (Polyvinyl Chloride)

– TP-CPE (Thermoplastic-Chlorinated Polyethylene) – TPPO (Thermoplastic Polyolefin - low smoke zero

halogen-transit industry) Thermoset

– Neoprene (PCP - Polychhloroprene)

– Hypalon (CSPE –ChlorosulfonatedPolyethylene) (discontinued)

– TS-CPE (Thermoset-Chlorinated Polyethylene)

– XLPO (Cross Linked Polyolefin - low smoke zero

halogen-transit industry)

Factory Tests

Factory Electrical Tests

• DC Conductor Resistance • Insulation Resistance (Megger) • Shield Continuity

• Corona (4 times operating; <5 pico Coulombs) • AC Withstand (200 v/mil, 5 minutes)

(64)

AC Withstand – 5 Minutes

Nominal Voltage Rating Nominal Wall Thickness (mils) 200 v/mil AC Test Voltage (kV) 5 kV-100% 90 18 5 kV-133% 115 23 5/8 kV-133/100% 140 28 15 kV-133% 175 35 15 kV-133% 220 44 25 kV-100% 260 52 28 kV-100% 280 56 25 kV-133% 320 64 28/35 kV-133/100% 345 69 35 kV-133% 420 84 200 v/mil x 220 mils = 44,000 v or 44 kV

AEIC PARTIAL DISCHARGE REQUIREMENTS

Maximum Permissible Discharge

______________________________________________________________________ Stress as a Percent of Rated Voltage to Ground

150% 200% 250% 300% 400%

1973 5 30 55 80 80 1975 5 20 35 50 -1982 5 20 35 50 -1983 Okonite established internal “flat line” requirement

1987 5 5 5 5 10

1996 5 5 5 5 5

Cable

Prep

(65)

(66)

80%

High Voltage but Low Stress

High Stress Area/Near Ground

Knife Cuts = Termination Failures

Wide SC Strips = Higher Stripping Tension

Outer Semicon Thickness-URD

Concentric Neutral Wires

Insul OD (inches) Min/Max (mils) Cable Sizes (conductor/insul thickness) 0-1.000 30/60 #2 to 3/0,220 #1 to 2/0, 260 1.001-1.5 40/75 4/0 to 750, 220 3/0 to 500, 260 1/0 to 350, 345 1.501-2.0 55/99 1000, 220 750 to 1000, 260 500 to 1000, 345

(67)

Outer Semicon Thickness- Non-URD

Cu Tape, LCS, fine wires

Insul OD (inches) Min/Max (mils) Cable Sizes (conductor/insul thickness) 0-1.000 24/60 #2 to 3/0,220 #1 to 2/0, 260 1.001-1.5 32/60 4/0 to 750, 220 3/0 to 500, 260 1/0 to 350, 345 1.501-2.0 40/75 1000, 220 750 to 1000, 260 500 to 1000, 345

Outer Semicon Thickness- Non-URD

Insul OD (inches) Min/ Max (mils) Cable Sizes (conductor/insul thickness) 0-1.000 24/60 #2 to 3/0,220 #1 to 2/0, 260 1.001-1.5 32/60 4/0 to 750, 220 3/0 to 500, 260 1/0 to 350, 345 1.501-2.0 40/75 1000, 220 750 to 1000, 260 500 to 1000, 345

ICEA

now allows

24 mils

ALL SIZES

Ripley Banana Peeler

(Semicon Scoring Tool)

_{Olfa 300 Cutter}

Speed Systems Spiral Semicon

Scoring Tool

(68)

A

B

Pull Direction ?

A to B ?

B to A ?

Question?

Cradled

Triplexed or Triangular

•Cradled – When cables are pulled in parallel.

•Triplexed – When cables are twisted together at factory. •Triangular – When cables pulled in parallel, but with a percent fill that is greater than 40%.

Triplexed (twisted) Cable on Reel Paralleled (side-by-side) Cable on One Reel

(69)

If the maximum pulling tension is

exceeded, the strands next to the

pulling eye can elongate and break.

It is possible to exceed the max

pulling tension and not damage the

Maximum Pulling Tension Calculation Tmax= 0.008 x n x CMA {For 1/C or Triangular}

and

Tmax= 0.008 x (n-1)x CMA {For Cradled}

where,

0.008 is the maximum force per circular mil area that can be exerted on the conductor without exceeding the tensile strength of the conductor. Examples For 3-1/C 350 mcm - Triangular T_max= 0.008 x 3 x 350,000 Tmax= 8400 lbs For 3-1/C 350 mcm - Cradled Tmax = 0.008 x (3-1) x 350,000 Tmax = 5600 lbs

Conductor Size No. of Conductors

AWG Cir. Mils n=1 n=2 n=3

2 66,360 530 1060 1595 1 83,690 670 1340 2010 1/0 105,600 845 1690 2535 2/0 133,100 1065 2130 3195 3/0 167,800 1342 2684 4026 4/0 211,600 1693 3386 5079 250 mcm 250,000 2000 4000 6000 350 mcm 350,000 2800 5600 8400 500 mcm 500,000 4000 8000 10000 750 mcm 750,000 6000 10,000 10000 1000 mcm 1,000,000 6000 10,000 10000 1250 mcm 1,250,000 6000 10,000 10000 1500 mcm 1,500,000 6000 10,000 10000 2000 mcm 2,000,000 6000 10,000 10000 Tension, Lbs

Maximum Pulling Tension Limits

Max Tension Limits 1 conductors = 6000 lbs 2 or more conductors = 10,000 lbs

EXAMPLES OF

COMPRESSION TYPE PULLING EYES AND BOLTS

Pulling eye.

Pulling bolt.

Pipe Cable

Pull

(70)

3-1/C Pulling Bolts in Yoke

3/C Common Pulling Eye

Maximum Pulling Tension

Limit Pulling Grips

to

1000 lbs per Grip

• Not just pulling on conductor • Pulling on jacket, shield and

insulation also.

• Damage can occur to these other layers.

• Where the damage starts or stops cannot be determined.

Condux

Re-useable Pulling Eye

(71)

Tapping in Wedge

Completed

(72)

3 and 4 Conductor Sling

Attached to Common Head

Dynamometer set-up on pull. Complicated: Most measure angles and distances then input into formula.

Line

Tensiometer

(73)

Sidewall Pressure

Simplified

For Single Conductor:

SWP = T

out

/r

_bend

Expressed in Lbs/foot of radius Smaller Radius = Higher “SWP”

Larger Radius = Lower “SWP”

Kirk

1000 LBS SWP on Rope 1000 LBS/1 ft= 1000 lbs/ft of radius George SWP on Rope 1000 LBS/10 ft= 100 lbs/ft of radius 1000 LBS

•Damage from excessive sidewall

pressure.

•Shield can cut into insulation and

cause failure.

Shield Damage from

Over-bending

(74)

Simple Min Bend Radii Gauge

NEC fill limits were designed to prevent fire hazards. They did not want an electrician installing 20 - #12 wires in a ½” conduit and creating a fire.

Percent Fill Calc

• 3-1/C 500 mcm, 15 kV in 5” Duct

• Cable OD = 1.49”

• Duct ID = 5.047”

• A = πR

2

_{-or- πD}

2

4

• Area _Cable= (π(1.49”)2_{/4) x 3 = 5.23 sq inch}

• Area _Duct = π(5.047”)2 _{= 20 sq inch, EHB p39, T 7-1}

• Fill = 5.23/20 x 100 = 26.15 %

Percent Fill Calc

• 3-1/C 500 mcm, 15 kV in 4” Duct

• Cable OD = 1.49”

• Duct ID = 4.026”

• A = πR

2

_{-or- πD}

2

4

• Area _Cable= (π(1.49”)2_{/4) x 3 = 5.23 sq inch}

• Area _Duct = π(4.026”)2 _{=12.72sq inch, EHB p39, T 7-1}

(75)

Effects of Duct Size

3-1/C 500 mcm Cu, 90C in 4” PVC,

36” to Top of Duct

Insulation

Thkns

175 mils

508 amps

220 mils

509 amps

580 mils

510 amps

Cable Clearance (min ½”)

Utilities are not bound by NEC % Fill Limits. They use cable clearance.

Jam Ratio in Round Duct

JR=2.8

JR=3.2

In Round Duct it does not make sense:

• at 2.8 there is not enough room for them to jam •at 3.2 there is enough room for the three of them •So why ????

JR=3.2

JR=2.8

JAM RATIO (ELONGATED DUCT)

Conduit Manufacturers are permitted, per industry standards, to make sweeps as much as 10% out of

round or Elongated.

Jamming

• If the jam ratio falls between 2.8 and 3.2, it does not mean the cables will automatically jam; it just means there is a possibility of jamming.

• The tendency to jam increases with pull length and the number of bends. Both of these increase tension.

• Remember, each bend increases tension significantly.