00924856 PDF BRITISH STANDARD BS EN 50187 1997 Gas filled compartments for a c switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV The European Standard EN 50187 199[.]
Trang 1BRITISH STANDARD BS EN
50187:1997
Gas-filled
compartments for a.c
switchgear and
controlgear for rated
voltages above 1 kV and
up to and
including 52 kV
The European Standard EN 50187:1996 has the status of a
British Standard
ICS 29.120.60; 29.260
Trang 2This British Standard, having
been prepared under the
direction of the Electrotechnical
Sector Board, was published
under the authority of the
Standards Board and comes
into effect on
15 March 1997
© BSI 11-1998
The following BSI references
relate to the work on this
standard:
Committee reference PEL/17/1
Draft for comment 93/205510 DC
ISBN 0 580 26917 5
Committees responsible for this British Standard
The preparation of this British Standard was entrusted by Technical Committee PEL/17, High-voltage switchgear, controlgear and co-ordination committee, to Subcommittee PEL/17/1, High-voltage switchgear and controlgear, upon which the following bodies were represented:
ASTA Certification Services Association of Manufacturers Allied to the Electrical and Electronic Industry (BEAMA Ltd.)
British Railways Board Copper Development Association ERA Technology Ltd
Electricity Association GAMBICA (BEAMA Ltd.) Ministry of Defence Safety Assessment Federation Ltd
Transmission and Distribution Association (BEAMA Limited) The following bodies were also represented in the drafting of the standard, through subcomittees and panels:
Association of Consulting Engineers British Cable Makers’ Confederation Electrical Installation Equipment Manufacturers’ Association (BEAMA Ltd.) Engineering Equipment and Materials Users Association
Institution of Incorporated Executive Engineers
Amendments issued since publication
Trang 3BS EN 50187:1997
Contents
Page
Trang 4ii © BSI 11-1998
National foreword
This British Standard has been prepared by Subcommittee PEL/17/1 and is the
English language version of EN 50187:1996 Gas-filled compartments for a.c switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV including its corrigendum, September 1996 published by the
European Committee for Electrotechnical Standardization (CENELEC)
A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application
Compliance with a British Standard does not of itself confer immunity from legal obligations.
Cross-references
Publication referred to Corresponding British Standard
EN 50052:1986 BS 6878:1988 Specification for high-voltage switchgear
and controlgear for industrial use Cast aluminium alloy enclosures for gas-filled high-voltage switchgear and controlgear
EN 50064:1989 BS 7315:1990 Specification for wrought aluminium and
aluminium alloy enclosures for gas-filled high-voltage switchgear and controlgear
EN 50068:1991 BS EN 50068:1991 Specification for wrought steel
enclosures for gas-filled high-voltage switchgear and controlgear
EN 50069:1991 BS EN 50069:1991 Specification for welded composite
enclosures of cast and wrought aluminium alloys for gas-filled high-voltage switchgear and controlgear
EN 60298:1996 BS EN 60298:1996 A.C metal-enclosed switchgear and
controlgear for rated voltages above 1 kV and up to and including 52 kV
EN ISO 9 000 series BS EN ISO 9 000 series Quality management and
quality assurance standards
EN 45020:1993 BS EN 45020:1993 Glossary of terms for
standardization and related activities
Summary of pages
This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, an inside back cover and a back cover
This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover
Trang 5EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
EN 50187
August 1996
ICS 29.120.60; 29.260.00
Descriptors: Enclosure, high-voltage switching devices, high-voltage metal-enclosed switchgear and controlgear, pressurized enclosure,
gas-filled compartments for rated voltages above 1 kV and up to and including 52 kV
English version
Gas-filled compartments for a.c switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
Compartiments sous pression de gaz
pour appareillage à courant alternatif de
tensions assignées supérieures à 1 kV
et inférieures ou égales à 52 kV
Gasgefüllte Schotträume für Wechselstrom-Schaltgeräte und -Schaltanlagen mit Nennspannungen über 1 kV bis einschließlich 52 kV
This European Standard was approved by CENELEC on 1995-11-28
CENELEC members are bound to comply with the CEN/CENELEC Internal
Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration
Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any
CENELEC member
This European Standard exists in three official versions (English, French,
German) A version in any other language made by translation under the
responsibility of a CENELEC member into its own language and notified to the
Central Secretariat has the same status as the official versions
CENELEC members are the national electrotechnical committees of Austria,
Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,
Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and
United Kingdom
CENELEC
European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B-1050 Brussels
© 1996 Copyright reserved to CENELEC members
Ref No EN 50187:1996 E
Trang 6© BSI 11-1998
2
Foreword
This European Standard was prepared by the
Technical Committee CENELEC TC 17C,
High-voltage enclosed switchgear and controlgear
The text of the draft was submitted to the formal
vote and was approved by CENELEC as EN 50187
on 1995-11-28
The following dates were fixed:
This European Standard is based on the general
specifications given in EN 60298:1996 which are
however not sufficient to satisfy the conditions for
the service allowance of pressurized high-voltage
switchgear and controlgear
These specifications are appropriate for pressurized
high-voltage switchgear enclosures allowing an
economic production without sacrificing aspects of
safety For unusual shapes dictated by electrical
conditions they permit the verification of sound
design by proof tests instead of calculations
For the time being reference can only be made to
published European and international standards as
far as they are appropriate for the purpose of
production of enclosures to be used in gas-filled
switchgear and controlgear
The present European Standard has been
established as an international specification for the
design, construction, testing and certification of
pressurized enclosures used in high-voltage
switchgear and controlgear This standard follows
to that extent also article 2 of the
Directive 76/767/EEC
National deviations from this European Standard
are listed in annex A (informative)
Contents
Page
– latest date by which the
EN has to be implemented
at national level by
publication of an identical
national standard or by
– latest date by which the
national standards
conflicting with the EN
have to be withdrawn (dow) 1996-12-01
Trang 7EN 50187:1996
Introduction
This standard covers the requirements for the
design, construction, testing, inspection and
certification of gas-filled compartments for use in
AC switchgear and controlgear or for associated
gas-filled equipment Special consideration is given
to these compartments for the following reasons:–
a) The compartments form the containment of
electrical equipment, thus their shape is
determined by electrical rather than mechanical
considerations
b) The equipment is operated by competent
persons (operators) only
c) As the thorough drying of the inert,
non-corrosive gas-filling medium is fundamental
to the satisfactory operation of the electrical
equipment it is checked at the original
pressurisation and periodically if applicable For
this reasons no internal corrosion allowance is
required on the wall thickness of these
compartments
d) The compartments are subjected to only small
fluctuations of pressure as the gas-filling density
shall be maintained within close limits to ensure
satisfactory insulating and arc-quenching
properties Therefore, the compartments are not
liable to fatigue due to pressure cycling
e) The operating pressure is relatively low
For the foregoing reasons, and to ensure the
minimum disturbance hence reducing the risk of
moisture and dust entering the compartments
which would prevent correct electrical operation of
the switchgear, no pressure tests shall be carried
out after installation and before placing in service
and no periodic inspection of the compartment
interiors or pressure tests shall be carried out after
the equipment is placed in service
1 Scope
1.1 Type of equipment
This standard applies to compartments pressurized
at a maximum pressure of 3 bar (gauge) and with a
maximum product pressure ´ volume of 2 000 bar
litres with inert gases, for example sulphur
hexafluoride or nitrogen or a mixture of such gases,
used in indoor or outdoor installations
of AC switchgear and controlgear with rated
voltages above 1 kV up to and including 52 kV
where the gas is used principally for its dielectric
and/or arc-quenching properties
The compartments comprise parts of electrical equipment not necessarily limited to the following examples:
Circuit breakers Switch disconnectors Disconnectors Earthing switches Current transformers Voltage transformers Busbars and connections Cable terminations Gas filled compartments having a design pressure exceeding 3 bar (gauge) or a product
pressure × volume exceeding 2 000 bar litres shall
be designed, manufactured and tested in accordance with one or a combination of the following:
EN 50052
EN 50064
EN 50068
EN 50069
1.2 Quality assurance
The switchgear manufacturer shall be responsible for achieving and maintaining a consistent and adequate quality of product
Sufficient examinations shall be made by the compartment manufacturer to ensure that the materials, production and testing comply in all respects with the requirements of this standard and ISO 3834 Inspection by user’s inspectors shall not absolve the switchgear manufacturer from this responsibility to exercise such quality assurance procedures as to ensure that the requirements and intent of this standard are satisfied
NOTE Reference should be made to the EN ISO 9 000 series
of standards for quality systems.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other
publications These normative references are cited
at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions
of any of these publications apply to this European Standard only when incorporated in it by
amendment or revision For undated references the latest edition of the publication referred to applies (including amendments)
Trang 84 © BSI 11-1998
3 Definitions
3.1
compartment
a part of gas-filled switchgear and controlgear
retaining the insulating gas under the prescribed
conditions necessary to maintain safely the rated
insulation level, protecting the equipment against
external influences
3.2
manufacturer
individual or body finally responsible for designing
and producing the compartment In this standard
this is the switchgear manufacturer, even when the
compartment is produced by a sub-manufacturer
3.3
design pressure (of a compartment)
pressure (gauge) used to determine the design of the
compartment It is at least the upper limit of
pressure reached within the compartment at the
design temperature
3.4
design temperature (of a compartment)
highest temperature reached by the compartment
which can occur under service conditions This is
generally the upper limit of ambient air
temperature increased by the temperature rise due
to the flow of rated normal current
NOTE Solar radiation and other relevant operating conditions shall be taken into account when they have a significant effect on the temperature of the compartment and on the mechanical properties of some materials Similarly, the effects of low temperatures on the properties of some materials shall be considered.
3.5 filling pressure (of a compartment)
the pressure in bar (gauge) assigned by the manufacturer referred to atmospheric air conditions
of 20 °C and 1 013 hPa at which the gas-filled compartment is filled before being put into service
4 Materials
Any suitable materials or combination of materials may be used for the manufacture of compartments, typical examples are:
Wrought mild steel Wrought austenitic stainless steel Wrought aluminium
Cast aluminium Cast resin The properties of the materials should be taken from the applicable standards
The materials properties shall be verified either by
a certificate from the supplier or tests carried out by the switchgear manufacturer
EN 50052 1986 Cast aluminium alloy enclosures for gas-filled high-voltage switchgear and
controlgear
EN 50064 1989 Wrought aluminium and aluminium alloy enclosures for gas-filled
high-voltage switchgear and controlgear
EN 50068 1991 Wrought steel enclosures for gas-filled high-voltage switchgear and
controlgear
EN 50069 1991 Welded composite enclosures of cast and wrought aluminium alloys for
gas-filled high-voltage switchgear and controlgear
EN 60298 1996 A.C metal-enclosed switchgear and controlgear for rated voltages above 1 kV
and up to and including 52 kV (IEC 298:1990 + corrigendum April 1995 + A1:1994)
EN ISO 9 000 series Quality management and quality assurance standards
(ISO 9 000 series)
EN 45020 1993 General terms and their definitions concerning standardization and related
activities (ISO/IEC Guide 2:1991)
Trang 9EN 50187:1996
5 Design
5.1 General
Consideration for design of compartments for gas
insulated switchgear prescribed in this clause takes
into account that the compartments are subjected to
particular operating conditions (see introduction)
which distinguish them from parts for compressed
air receivers and similar storage vessels
5.2 Corrosion allowance
The compartments are filled in service with a
non-corrosive thoroughly dried gas, therefore, no
internal corrosion allowance is necessary
5.3 Design considerations
The geometry of a compartment can be determined
by electrical rather than mechanical considerations
This constraint can result in a compartment
geometry which requires an unacceptable degree of
calculation or which cannot be calculated at all
In the case of such a compartment or a compartment
for which calculations are not made, a proof test in
accordance with clause 7.3 is necessary.
When designing a compartment, account shall be
taken of the following, if applicable:
a) The possible evacuation of the compartments
as part of the filling process
For compartments of this type it is usually
necessary to evacuate the air before introducing
gas pressure, this ensures purity of the gas The
evacuated condition is therefore not an
operational condition and in most cases
compartments designed for internal pressure
will be suitable for the evacuated condition
without buckling
b) The resulting pressure in the event of an
accidental leak between compartments having
different pressures
c) The full differential pressure possible across
the compartment wall
d) Superimposed loads and vibrations by external
effects
e) Stresses caused by temperature differences
including transient conditions and by differences
in coefficients of thermal expansion
f) Effects of solar radiation when applicable
g) Dynamic stress due to short circuit current
When the strength of the compartment or part
therefore has not been determined by calculation,
proof tests shall be made in order to demonstrate
that the permissible design stress is not exceeded at
the design pressure and at the design temperature
(see 7.3).
5.4 Calculation methods
When the wall and flange thicknesses of the compartment are calculated the permissible design
stress shall be taken from 5.8 Because of the
various shapes, sizes, and materials used it is not possible to design such compartments using equations from conventional pressure vessel codes, therefore established methods should be used, using the design pressure and the design temperature as
defined in 3.3 and 3.4.
NOTE Pressure stress due to an internal electrical fault is not
a design parameter.
For the case of arcing due to an internal fault, reference is made
to EN 60298:1996.
5.5 Manholes and Inspection openings
No manholes or inspection openings are necessary for inspection of the compartment
5.6 Design pressure
The design is based on the design pressure as
defined in 3.3.
5.7 Design temperature
The selection of material and the determination of the design stress depend upon the highest wall temperature which can be expected during service
at the design pressure as defined in 3.4.
5.8 Design stress basis
The nominal design strength shall be selected from the material standards For castings the nominal design strength of the material without heat treatment shall be used in the heat affected areas of welds For wrought aluminium, parts the nominal design strength in the annealed condition shall be used in the design of welded structures
Design stresses can be established either by calculation or proof tests
The permissible design stress (fa) at the design pressure and at the design temperature including the safety factor of the appropriate equations is given by:
where:
Rm: Minimum tensile strength of the material at the design temperature taken from the material standard
3,0 is the safety factor
The calculation may be made on higher values of tensile strength if the values are guaranteed by a material certification
fa Rm 3,0
=
Trang 106 © BSI 11-1998
6 Manufacture and workmanship
Manufacture must be carried out in accordance with
sound engineering practice Any welding shall be
carried out by welders who have successfully carried
out welder procedure tests for the particular joint
Where automatic machine welding is employed the
initial setting of the machine must be verified for
each weld configuration by a test specimen before
production commences
Periodically the performance of the equipment shall
be verified by an identical test specimen
7 Inspection and testing
7.1 General
Each compartment shall be inspected during
construction Sufficient inspections shall be made to
ensure, that the materials, construction and testing
comply in all respects with the requirements of this
standard
7.2 Routine pressure test
Pressure tests shall be carried out on all
compartments after manufacture Each
compartment shall be subjected to a test pressure
of 1,3 times the design pressure for
at least one minute
As far as possible the test should be carried out on
completely assembled compartments
This does not apply for compartments with rated
filling pressure (as per clause 3.5) of 0,5 bar (gauge)
and below
After this test the compartments shall show no
signs of distress or distortion likely to affect the
operation of the switchgear
7.3 Proof tests
For each design of compartment which is not
calculated or where doubt exists regarding the
accuracy of the calculations a proof procedure shall
be carried out as follows:
The proof procedure shall be a pressure withstand
test carried out on one compartment for each type of
design of representative compartments
Because of the variety of versions of compartments
in switchgear and controlgear it is not practical or
necessary to make pressure withstand tests for
every design of compartments, furthermore, the
compartments sometimes differ only in regard to
individual details which have no influence on the
pressure withstand
The performance of any particular arrangement
may be substantiated by test results from
comparable arrangements
When proof tests are carried out on compartments which will be subjected to significant superimposed loads in service the effect of these loads shall be simulated during the test
Each representative design of compartment shall withstand a pressure of 3,0 times the design pressure for 1 minute During the test the pressure rise shall not exceed 400 kPa/min After the test the compartment may be distorted
The test may be carried out without pressure relief devices, if fitted The replacement of pressure relief devices for the pressure withstand test shall not have any effect on the strength of the compartment Compartments having pressure relief devices which are integrated may have the devices supported or replaced during the test providing this does not increase the withstand pressure of the
compartment
Any compartment surviving the test shall be scrapped
8 Pressure relief devices
8.1 General conditions
If necessary, compartments within the scope of this standard shall be provided with protective devices Typical examples are:
a) Bursting discs b) Self-closing valves c) Non-self-closing devices d) Integrated pressure relief devices The protective devices shall be constructed, located and installed so that they are accessible for
inspection and repair They shall be protected against accidental damage
The devices need not be installed directly on the compartment The discharge areas and any connecting ports to or within the compartment shall
be of adequate size to permit effective relief in the event of overpressure
Pressure relief devices shall be arranged so as to minimize the danger to an operator during the time
he is performing his normal operating duties Pressure relief devices may be connected to the compartment or in the gas supply lines of the gas-filling plant
In the case of devices fitted to compartments connected to an external source of pressure these shall be designed to limit the pressure to 1,1 × the design pressure In the case of devices fitted in gas supply lines of the gas-filling plant these shall be designed to limit the overpressure to 1,1 times the filling pressure