Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 9511 (1980): Earth knobs for neutral conductors [ETD 37:Conductors and Accessories for Overhead Lines]

IS : 9511 - 1980

Indian Standard SPECIFICATION FOR

EARTH KNOBS FOR NEUTRAL CONDUCTORS

Code of Practice for Power Installation and Maintenance Sectional Committee, ETDC 20

Chairman Representing

SHRI K.S. SUBRAHMANYAM Bharat Heavy Electricals Ltd, Bangalore

Members

SHRI S. GOVINDARAJ ( Alternate Shri K. S. Subrahmanyam)

SHRI B.C. ALVA SRRI T. N. R. RAO ( Alternate )

SHRI M. J. ANANDAMURTHY

to

Kamataka Electricity Board, Bangalore

The Chief Electrical Inspector to the Government of Tamil Nadu, Madras

SHRI P. D. BAQADE SHRI R. C. BAJPAI (Alternate )

Tata Consulting Engineers, Bombay

SHRI M . D . BHALERAO Maharashtra State Electricity Board, Bombay SHRI S. N. AQASHE (Alternate )

SHRI V. S. BHATIA Siemens India Ltd, Bombay SHRI M A. NOORUDXN ( Alternate )

SHRI K. K. BOSE The Calcutta Electric Supply Corporation Ltd, Calcutta

SHRI A. CHATTERJEE ( Alternate ) SHRI K. V. CRAUBAL The Federation of Electricity Undertakings of

India, Bombay SHRI K. S. Josm (Alternate )

CHIEF ELECTRICAL ENQINEER, NR Railway Board ( Ministry of Railways ) JOINT DIRECTOR STANDARDS, *

RDSO ( Alternate ) SHRI B. L. DESHPANDE Electrical Engineer to Government of

Maharashtra, Bombay SHRI DEVENDER NATR Larsen & Toubro Limited, Bombay

SHRI I. C. JOSEPH (Alternate) SHRI K. W. DHARXADHIKARI Jyoti Limited, Vadodara SHRI S. V. MARFATIA Tariff Advisory Committee, Insurance Association

of India, Bombay SHRI S. N. BANDYOP~DHYAY (Alternate)

( Continued on page 2 )

0 Copuright 1980 INDIAN STANDARDS INSTITUTION

This publication is protected under the Indian Copyright Act (XIV of 1957) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act.

IS :9511- 1980

( Continuedfrom fiage 1 )

Members Representing

SHRI K. SUDHAEARAN NAIK Kerala State Electricity Board, Kerala SHRI R. ANANTHASUBRAMONIA

IYER ( Alternate ) SHHI R. NATARAJAN Central Public Works Department, New Delhi

SHRI V. K. KA~OOR (Alternate ) SHRI K. P. R. PILLAI Fact Engineering and Design Organization,

SHRI C.R.R. MENON ( Alternate) Udyogamandel

LT.COL B. B. RAJPAL Engineer-in-Chief’s Branch, Army Headquarters ( Ministry of Defence )

SHRI R. S. KANWAR ( Alternote) SHRI RANES RAY CROUDHURI Engineering Construction Corporation Ltd,

Bombay SHRI L. E. D. CRWZ (Alternate)

SHRI I. C. SANDER SRRI P. S. SAWHNEY ( Alternate )

Delhi Electric Supply Undertaking, New Delhi

SHHI SARDUL SINQK Chief Electrical Inspector to Government of Punjab, Chandigarh

SHHI P. K. SAXENA Rural Electrification Corporation, New Delhi SRRI G. L. DUA ( Alternate )

SHHI A. N. SINCUI Central Electricity Authority, New Delhi SRBI P. M. AIXLUWALIA ( Alternate )

SRRI K. G. SHANMUKHAPPA NGEF Limited, Bangalore SHRI A. N. SRIVATHSA ( Alternate )

DR T. C. SIDHAN Chief Electricity Inspector to the Government of Kerala, Trivandrum

SHRI T. SRINIVASAN SHRI N. NAQAPPAN ( Alternate )

Tamil Nadu Electricity Board, Madras

SHHI G. N. THA~ANI Engineers India Limited, New Delhi SHHI M. K. DAS ( Alternate )

SHRI D. M. VATCHA The Bombay Electric Supply and Transport

SH~I B. M. SAMANT (Alternate ) Undertaking, Bombay

SHRI S. P. SACEDEV, Director General, IS1 ( Ex-ojicio Member) Director ( Elec tech)

Secretary’ SHRI K. GANESH

Assistant Director ( Elec tech ), ISI

2

IS : 9511 - 1980

Indian Standard SPECIFICATION FOR

EARTH KNOBS FOR NEUTRAL CONDUCTORS

0. FOREWORD

0.1 This Indian Standard was adopted by the Indian Standards Institution on 23 May 1980, after the draft finalized by the Code of Practice for Power Installation and Maintenance Sectional Committee had been approved by the Electrotechnical Division Council.

0.2 Earth knobs for neutral conductors are used for grounding of metal parts of supporting structures in electric lines, in order to ensure a sure path for the fault current. They ensure good earth connection at every pole and restrict development of voltage on the neutral conductors. These are better in performance in comparison to steel boits and nuts which are also employed for this purpose.

0.3 This standard is formulated with a view to specifying the minimum requirements that the earth knobs shall conform to. It also specifies the dimensions of the knob.

0.4 In order to give guidance on the manner in which the earth knobs could be used, a typical arrangement of the insulators and the earth knob in the horizontal and vertical formation of electrical lines are shown in Appendix A. While this gives the arrangement on inter- mediate poles, for guidance on arrangements at dead end, and for special supporting structures, reference shall be made to the construction standards of the relevant authority.

0.5 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test, shall be rounded off in accordance with IS : 2 - 1960*. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.

1. SCOPE

1.1 This standard covers the requirements of earth knobs used for earthing of metal parts of supporting structures of electric lines for over- head power lines with a nominal voltage up to 1 000 V.

*Rules for rounding off numerical values ( revised).

3

IS : 9511 - 1980

2. MATERIALS

2.1 Earth knobs shall be made of cast iron or suitable aluminium alloy.

3. GENERAL REQUIREMENTS

3.1 Earth knobs shall not have blow holes and shrinkage and other casting defects. The top and bottom flat portion of earth knob shall be smooth and horizontal.

3.2 The bore of the earth knob shall have a smooth and round profile for accommodating the fixing bolt. If a core is used for the purposes of moulding, it shall be single piece either from core blowing machine or by some other suitable method to give the core perfect roundness.

4. DIMENSIONS

4.1 The dimensions of earth knob shall conform to those shown in Fig. 1.

4.2 The dimensions are typical of the knob to satisfy the test require- ments in 5.

5. TESTS

5.0 The following tests shall be carried out on the earth knob to prove aompliance with this standard.

5.1 Test for Electrical Resistance

5.1.1 The electrical resistance of the earth knob shall be measured using a Kelvin bridge. Adequate electrical contact shall be ensured against the two flat surfaces of the knob preferably by using brass washers, soldered ,to the leads going to the bridge circuit. The washers shall be of adequate size to ensure sufficient area of contact.

5.1.2 The electrical resistance of the earth knob, measured as given in 5.1.1, between the two flat portions shall not exceed 200 m L?.

5.2 Test for Mechanical Strength

5.2.1 The breaking strength at the neck of the earth knob shall not be less than 11 500 kg.

6. MARKING

6.1 The earth knob and package shall be marked with the name of the manufacturer or his trade-mark,

4

All dimensions in millimetres.

FIG. 1 DIMENSIONS OF EARTH KNOBS

6.1.1 Earth knob may also be marked with the IS1 Certification Mark. NOTE - The use of the IS1 Certification Mark is governed by the provisions of

the Indian Standards Institution (Certification Marks ) Act and the Rules and Regulations made thereunder. The IS1 Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well-defined system of inspection, testing and quality control which is devised and supervised by ISI and operated by the producer. IS1 marked products are also continuously checked by IS1 for conformity to that standard as a further safeguard. Details of conditions under which a licence for the use of the IS1 Certification Mark may be granted to manufacturers or processors, may be obtained from the Indian Standards Institution.

5

IS : 9511 - 1980

APPENDIX A

( Clause 0.4 )

TYPliCAL ARRANGEMENT OF EARTH KNOB ZN SUPPOR~G STRUCTURES OF ELECTRICAL LINES

A-O. Given below are typical arrangements of the earth knob on the Supporting metal structures of electrical lines. The clearances hetween lines shall be according to the relevant standard,

A-l. HORIZONTAL FORMATXON

FIG. 2 EARTH KNOB AND INSULATORS IN HORIZONTAL FORMATSON

6

IS : 9511 - 1980

A-2. VERTICAL FORMATION

-4

-4

-4

-4

f NEUTRAL CUM’ EARTH WIRE

-

FIG. 3 EARTH KNOB AND INSULATORS IN VERTICAL FORMATION

INDIAN STANDARDS

ON

CODES OF PRACTICE FOR POWER INSTALLATION AND MAINTENANCE

IS:

732- .1963 Code of practice for electrical wiring installations ( system voltage not exceeding 650 volts ) ( retied )

900-1965 Code of practice for installation and maintenance of induction motors ( revised )

1866-1978 Code of practice for maintenance and supervision of insulating oil in service ( jirst revision )

18861967 Code of practice for installation and maintenance of transformers (Jirst revision ) 2274-1963 Code of practice for electrical wiring installations (system voltage

exceeding 650 volts ) 2309-1969 Code of practice for the protection of buildings and allied structures

against lightning (first revision ) 2551-1963 Danger notice plates 3043-1966 Code of practice fot earthing 3072-1975 Code ofpractice for installation and maintenance of switchgear (Jirst r&&n ) 3106-1966 Code of practice for selection, installation and maintenance of fuses ( voltage

not exceeding 650 volts ) 3914-1967 Code of practice for selection of ac induction motor starters ( voltage not

exceeding 1 000 volts ) 4648-1968 Guide for electrical layout in residential buildings 5124-1969 Code of practice for installation and maintenance of ac induction motor

starters ( voltage not exceeding 1 000 volts ) 5216-1969 Guide for safety procedures and practices in electrical work 5578-1970 Guide for marking of insulated conductors 5613 (Part I/Set 1 )-1970 Code of practice for design, installation and maintenance of

overhead power lines: Part I Lines up to and including 11 kV, Section 1 Design

5613 ( Part I/Set 2)-1971 Code of practice for design, installation and maintenance of overhead power lines: Part I Lines up to and including 11 kV, Section 2 installation and maintenance

5613 ( Part II/Set I)-1976 Code of practice for design, installation and maintenance of overhead power lines : Part II Lines above 11 kV up to and including 220 kV, Section 1 Design

5613 ( Part II/Set 2)-1976 Code of practice for design, installation and maintenance of overhead power lines : Part II Lines above 11 kV up to and including 220 kV, Section 2 Installation and maintenance

5908-1970 Method of measurement of electrical installation in buildings 5987-1970 Code of practice for selection of switches ( voltage not exceedmg 1 000 V ) 7689-1974 Guide for the control of undesirable static electricity 7733-1975 Code of practice for electrical wiring installation in hospitals 7752 ( Part I )-1975 Guide for improvement of power factor in consumer installation:

Part I Low and medium supply voltages 7987-1976 Guide for selection of high voltage circuit-breakers 8061-1976 Code ofpractice for design installation and maintenance of service lines 8437-1977 Guide on effects of currents passing through human body 8884 1978 Code of practice for the installation of electric bells and call system 8925-1978 Warning symbol for dangerous voltages 8969-1978 Code of practice for installation and maintenance of impulse and electronic

master and slave electric clock systems