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.
1 +, 1 +
01 ' 5
The Right to Information, The Right to Live
Step Out From the Old to the New
Mazdoor Kisan Shakti Sangathan
Jawaharlal Nehru
IS 9921-5 (1985): Alternating Current Disconnectors
(Isolators) and Earthing Switches for Voltages Above 1 000
v, Part 5: Information to be Given with Tenders, Enquiries
and Orders [ETD 8: High Voltage Switchgear and Controlgear]
! $ ' +-
Satyanarayan Gangaram Pitroda
Invent a New India Using Knowledge
! > 0 B
BharthariNtiatakam
Knowledge is such a treasure which cannot be stolen
IS : 9921 ( Part 5 ) - 1985
( Reaffirmed 2002 )
Indian Standard
SPECIFICATION
FOR
ALTERNATING
CURRENT DISCONNECTORS
( ISOLATORS ) AND EARTHING SWITCHES
FOR VOLTAGES ABOVE 1000 V
PART
INFORMATION
TO BE GIVEN WITH
ENQUIRIES AND ORDERS
TENDERS,
( SecondReprint DECEMBER 11-)97)
UDC 621.316.545.025:621.3.027.6
BUREAU
MANAK
OF
BHAVAN,
INDIAN
9
BAHADUR
STANDARDS
SHAH
ZAFAR
MARG
NEW DELHI 1lOOU2
Cl-2
May. 1.986
...
-._
L*
IS : 9921 ( Part 5 ) .. 1985
Indian Standurd
SPECIFICATION FOR
ALTERNATING
CURRENT DISCONNECTORS
(ISOLATORS ) AND EARTHING SWITCHES
FOR VOLTAGES ABOVE 1000 V
PART
INFORMATION
TO BE GIVEN WITH
ENQUIRIES
AND ORDERS
High Voltage
Switchgear
and Controlgear
Committee,
ETDC 58
TENDERS,
Sectional
Reprcsen!ing
Chairman
The Ahmedabad
SH~I H. M. PA1
Electricity
Co Ltd.
Ahmadabati
Members
SHEI M. B. BAH~~L~~AB( Alfernafe to
Shri H. M. Pai j
Tata
SMT C. BALIGA ( ALtern&
Hydro-Electric
Uombav
Power
Supply
C;O Ltd.
Central Public Works Department,
New Delhi
Snav~uon
OB Wonl;s III ( Alternate 1
Central Power Research Institute, Bangalorc
DIRECTOR
JOINT DIRECTOLS, STD ( .4lfcrnute I )
SR. DY DII~E~TOR ( A~ternatc
11 )
Central Electricity
Authority, New Delhi
DIRECTOR, SUB-STATION
DEPUTY DIR%:(:TOII, SUR-STATION
CJXIEB
,hWIN,U!.X~
( hEC
) I I
( Alternate)
Rurad
SFIRI G. L. DUA
SHRI S. C. KIIIJ~EANA ( nlfcrnat~ )
IIZiectrification
ASEA Ltd, Nasik
Snnr B. V. ESWAIL
SRRI S. SIJBIZAMANI~N ( Alternate )
Directorate
General
Sam K. L. Galto
New Delhi
SHUI R. V. NAI~AYANAN ( Alternate )
Corporation
of Supplies
Ltd,
2nd
N,aw
Disposals,
( Continued on page 2 )
Q
BUREAU
OF
Copyright 1385
INDIAN
STANDARDS
This publication
is protected under the Zt&rr Copyright Act ( XlV
of 1957 ) and I
reproduction in whole or in part by any means except with written permission of the
publisher shall be deemed to be an infriqement
of copyright under the said Act.
IS : 9921 ( Part 5 ) - 1985
( Continued
frompugs1 )
Members
Represeking
SHRI T. K. GHOSE
Calcutta
Electric
Supply
Corporation
Ltd,
Calcutta
SHRI G. CHATTERJEE ( Altcrnarc )
SHHI B. N. GHOSH
Bharat Heavy Electricals Ltd, Hyderabad
SHHI V. RA~HAVAN ( Alternate )
SHRI Y. R. GODSE
Bombay Electric Supply and Transport Undertaking, Bombay
SHRX D. SWAMINATHAN ( Alternate )
Kirloskar ASEA Limited, Bangalore
SHRI JAYANT N. GURJAR
Maharashtra State Electricity Board, Bombay
SHI~I P. D. JA~IAQIR~AH
NGEF Limited, Bangalore
Smr JAV~ED AHMED
SHUI K. P. SARATHY ( Alternate )
Aluminium Industries Limited, Kundara
SERI P. M. JOVEPH
SHRI C. M. A. NAYAR ( AItcrnnte )
JOINT DIRECTOR
National Test House, Calcutta
Saur P. C. PRADHAN ( Alternate )
SHRI B. N. KISHORE
Crompton Greaves Ltd, Bombay
SHRI A. N. VENUOOPAL ( Alternate )
Hindustan Brown Boveri Ltd, Bombay
SHRI V. S. MANI
&IRI
S. R. POTNIS
( Alternate )
Tata Consulting Engineers, Bombay
SEW S. G. MENON
SHI~I C. S. KUXAR ( Altcrnatc )
Mysore Electrical Industries, Bangalore
SHRI B. S. NARASIMHAN
SEHI K. SATYANA~AYANA SHARMA
( Alternate )
Jyoti Limited, Vadodara
SHRI J. S. NE~I
SHRI V. B. DESAI ( Alternate )
Siemens India Ltd, Bombay
SHRI S. G. NENE
SHRI H. D. TUN~ARE ( Alfcrnatc )
Delhi Electric Supply Undertaking, New Delhi
SHRI A. S. PINTO
SHRI 0. P. ANAND ( Alternate )
Tamil Nadu Electricity Board, Madras
SHRI T. E. B. SAIUUEL
SHRI T. S~EYBAHARAJAN (Ahnote
)
Indian Institute of Technology, New Delhi
REPRESENTATIVE
Research,
Design & Standards
Organization,
RXPRESENTATIVE
Lucknow
Director General, IS1 ( Ex-O&&J Member )
SHRI
S. P. SACHDEV,
Director ( Elec tech )
SHRI K. GANESH
Deputy Director ( Elec tech ), IS1
IS : 9921 ( Part 5 ) - 1985
Indian Standard
SPECIFICATION
FOR
ALTERNATING
CURRENT DISCONNECTORS
(ISOLATORS ) AND EARTHING SWlTCHES
FOR VOLTAGES ABOVE 1000 V
PART
INFORMATION
TO BE GIVEN WITH
ENQUIRIES AND ORDERS
0.
TENDERS,
FOREWORD
0.1 This Indian Standard
( Part 5 ) was adopted by the Indian Standards
Institution on 2 1 February 1985, after the draft finalized by the High Voltage
Switchgear and Controlgear
Sectional Committee
had been approved by,
the Electrotechnical
Division Council.
0.2 With the large scale manufacture
of air-break
disconnectors
in India,
the need for specifying uniform requirements
of such equipment
was felt,
particularly in view of different practices being followed by the manufacturers who have tie-ups with different
overseas
manufacturers.
This
standard was originally prepared as IS : 1818-1972*
to meet this need and
to provide guidance to the new manufacturers
in this field.
0.3 The first revision of IS : 1818-I972*
was done in 1972 mainIy to take
into account the developments
at the international
level and for expanding
the scope to cover ratings up to 420 kV.
However, in the last few years
in the field of high voltage switchgear,
there has been
considerable
advancement
in knowhow on the performance
of the equipment
which
calls for stipulations
that should be precisely made
in the national
standards.
This standard [ IS : 9921 ( Part 5 ) J has been formulated to
take these developments
into account.
0.4
This standardhas
Part
1 General
been brought
out in the following
five parts:
and Definitions
Part 2 Rating
Part 3 Design
*Alternating
and Construction
current isolators
( disconnectors
) and earthing switches
(first revision).
I$ : 9921 ( Part 5 ) - 1985
I,;ri ,t Type
Tests _trr(! Routine
l;,r t 5 Inlc)rmation
Tests
to LK Given with Iendc~ i lG_kics
:iil the par-ts shall be read in conjunction
and Orders.
with one another.
Ihis standard ( Part 5 ) summerizes the information
required to be
enquiries
and orders
and partly
replaces
IS :
i>1$?.I
I ujth tt:rders~
;!Il,j_i!i72*.
All the parts in the series together
will replace IS : 1818,
c:~nr;)l::tcly.
0.5 While preparing this standard, assistance has been derived from IEC
Pub 129-1975 c Altrrnating
current disconnectors
( isolators ) and earthing
Electrotechnical
Commission.
switches published by the International
This standard ( Part 5 ) conforms appreciably to this IEC: Pub and there
;rre no major deviations.
requirement
of this
0,6 For the purpose of decidin g whether a particular
staxldard is complied
with the final value,
observed
or calculated,
with
expressing the result of a test. shall be rounded off in accordance
I S . 2-I %Ot. Thr number of significant places retained in the rounded off
ztluc ~;hould be the same as that of the specified value in this standard.
1. SCOPE
1.1 This standard ( Part 5 ) covers particulars that should be supplied by
the enquirer while enquiring for or ordering equipment
and the technical
particulars that should be given by the manufacturers
with tenders.
1.2 Equipment
falling under the scope
system voltages above 1 000 V ac.
of this standard
1.3 For detailed scope of this series of standards
earthing switches, see 1 of Part 1 of this standard.
2. INFORMATION
ORDERS
2.1 When enquiring
following particulars
a) Particuiars
frequency,
*Nternating
TRulcs
cltrrrnt
for rounding
TO
BE
GIVEN
WITH
are intended
on disconnectors
ENQUIRIES
for or ordering a disconnector
or earthing
should be supplied by the enquirer:
for
alrd
AND
switch,
the
of system, that is, nominal
and highest
voltages,
number of phases and details of neutral earthing.
isolators ( disconnectors
) and
off numerical
values ( reuiscd ).
earthing switches
( jrd
revision).
IS : 9921 ( Part 5 ) - 1985
b)
Service conditions
( see 2 of Part 1 of this standard ) including
minimum and maximum ambient air temperatures,
the latter, if
greater than the normal values; altitude if over 1 000 m; and any
special conditions likely to exist or arise, for example, unusual
fumes, explosive gases,
exposure to steam or vapour, moisture,
excessive dust or salt air.
c)
Characteristics
of a disconnector
information
should be given:
or earthing
switch. The following
1) Number of poles;
2) Class: indoor or outdoor;
3) Rated voltage;
4) Rated insulation level where a choice exists between different
insulation
levels corresponding
to a minimum
given rated
voltage or, if other than standard, desired insulation level;
5)
Rated
frequency;
6)
Rated
normal
7) Rated
8)
current
short-time
( for disconnectors
withstand
Rated
short-circuit-making
switches only );
9) If other than standard,
circuit;
10) Mechanical
11) Mounting
earthing
terminals
conditions
switch;
current;
current,
specified
if
value
and connections
( for
earthing
of duration
of short-
on the disconnector
type tests specified
under
special
pollution and radio interference
); and
disconnectors
Class B switching
any
load;
12) The
13) For
only );
of rated voltage
surge requirements.
d) Characteristics
of the operating mechanism
ment, in particular, the following:
request
> 420 kV,
( artificial
Class
and associated
1) Method of operation, whether manual or power;
2) Number and type of spare auxiliary switches;
3) Rated supply voltage and rated supply frequency;
4) Requirements concerning the use of compressed
and
and
gas.
or
equip-
IS : 9921 ( Part 5 ) - 1985
No,w; - The enquirer should give information
of any special
included above that might influence the tender or the order.
3. INFORMATION
conditions
n>t
TO BE GIVEN WITH TENDERS
3.1 When the equirer requests technical particulars of a disconnector
or
earthing switch, the following information, where applicable, shall be given
by the manufacturer with the descriptive matter and drawings:
a) Rated values and characteristics
1) Number
of poles;
2) Class: indoor or outdoor;
3) Rated
voltage;
4)
Rated
insulation
5) Rated
frequency;
6) Rated
normal
7) Rated
short-time
level;
current
( for disconnectors
withstand
8) Rated
short-circuit-making
only );
only );
currents;
current
( for
earthing
9) The type tests specifirtl under special request
tion and radio interference
); and
switches
( artificial
IO) For disconnectors
of rated voltage > 420
Class B switching surge requirements.
b) Type tests - Certificate or report on request.
kV,
pollu-
Class
A or
c) Constructional features
1) Mass of complete
disconnector
or earthing
switch;
2) Pressure and limits of pressure between which the disconnector
or earthing switch will operate correctly
( operated by pneumatic or hydraulic device );
3) Minimum
clearances
i) between
in air:
poles,
ii) to earth,
iii)
for isolating
distance
( for disconnectors
4) For divided frame assembles,
isolating distance or gap.
how
only ); and
to achieve
and adjust
the
IS : 9921 ( Part 5 ) - 1985
d) Operating
equipment
1) Type
2) Rated
mechanism
of a disconnector
of operating
mechanism;
supply voltage
or earthing
and/or pressure
3) Current
required
at rated supply
disconnector
or earthing switch;
switch
of operating
voltage
4) Quantity
of free gas required to operate the
earthing switch at the rated supply pressure;
5) Number
and type of auxiliary
of indicating
mechanism;
operate
the
disconnector
or
contacts;
6) Design of the device or description
position; and
7) Design
to
and associated
of means
for securing
the
device.
e) Overall dimensions and other information - The manufacturer
should
give the necessary.information
as regards the overall dimensions
of the disconnector
or earthing
switch in the open and closed
positions and details necessary for the design of the foundation.
General information
regarding maintenance
should also be given.
4. NAMEPLATES
4.1 Disconnectors,
earthing switches and their operating devices shall be
provided with a nameplate which contains the illformation
in accordance
with Table 1. For outdoor disconnectors
or earthing switches, the nameplate shall be weather-proof
and corrosion-proof.
If a disconnector
or earthing
switch consists of several
poles, each pole shall be provided with a nameplate.
independent
4.2 For a combined operating device and disconnector
or earthing switch,
it may be sufficient to use only one combined
nameplate
for both parts.
The same applies to combined disconnectors
and earthing switches.
The nameplate
installation.
shall be visible in the position
of normal
service
and
IS : 9921 ( Part 5 ) - 1985
TABLE
INFORMATION
ON NAMEPLATES
( Ckluse 4.1 )
ABBRE-
UNIT
VIATION
Manufacturer
DISCON-
EARTH-
NECTolt
INQ
TINO
SWITCH DEVICE
OPERA-
[XI
(X)
__.___
Designation of type
~
Serial number
..-
---
Un
kV
27,
kV
(X)*
Rated
switching
impulse
withstand
voltage and the Class ( A or B ) of the
equipment, for rated voltages 300 kV
and above
Us
kV
Rated normal
In
current
zth
kA
current
Ith
kA
(X)
(X)
Rated
voltage
__Rated
lightning
voltage
impulse
current
Rated
short-time
withstand
Rated
short-circuit
Value of short-time
second
making
if different
Rated pressure of compressed
Rated
auxiliary
Rated
mechanical
Mass ( including
NOTE -
withstand
from 1
gas
voltage
terminal
load
liquid )
The word rated
--.
(Xl
(Xl
N/m8
us
(X)
kg
(X)
(X)
= The marking
of these values is mandatory,
= The marking
of these values is optional,
for Un > 725 kV
(Xl
W)
need not appear on the nameplate.
(X)
*Mandatory
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STANDARDS
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