AS EN 50069 pdf download – Welded composite enclosures of cast and wrought aluminium alloys for gas- filled high-voltage switchgear and controlgear

AS EN 50069 pdf download – Welded composite enclosures of cast and wrought aluminium alloys for gas- filled high-voltage switchgear and controlgear
This document applies to welded composite enclosures of cast and wrought aluminium alloy pressurizedwith dry air, inert gases (e.g. sulphur hexafluoride or nitrogen or a mixture of such gases), used in indoor andoutdoor installations of high-voltage switchgear and controlgear with rated voltages above 1 kV, where thegas is used principally for its dielectric and/or arc-quenching properties with rated voltages:
– above 1 kV and up to and including 52 kV concerning gas-filled compartments with design pressure
higher than 300 kPa relative pressure (gauge);
-above 52 kv concerning all gas-filled compartments.
The enclosures comprise parts of electrical equipment not necessarily limited to the following examples:-circuit-breakers;
switch-disconnectors;disconnectors;
earthing switches;
current transformers;
voltage transformers;
surge arrestors;
— busbars and connections;
-etc.
The scope also covers enclosures of pressurized components such as the centre chamber of live tankswitchgear, gas-insulated current transformers, etc.
2Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutesrequirements of this document.For dated references, only the edition cited applies. For undated references,the latest edition of the referenced document (including any amendments) applies.
EN 13445-8:2014，Unfired pressure vessels – Part 8: Additional requirements for pressure vessels ofaluminium and aluminium alioys
EN 50052:2016, High-voltage switchgear and controlgear – Gas-illed cast aluminium alloy enclosures
EN 50064:2018，High-voltage switchgear and controlgear—Gas-illed wrought aluminium and aluminiumalloy enclosures
EN 62271-1:2017,High-voltage switchgear and controlgear – Part 1: Common specifications for alternatingcurrent switchgear and controlgear (lEC 62271-1:2017)
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and lEC maintain terminological databases for use in standardization at the following addresses:·IEC Electropedia: available at http://www.electropedia.orgl
. isO Online browsing platform: available at http://www.iso.orglobp
3.1
enclosure
part of gas-insulated metal-enclosed switchgear retaining the insulating gas under the prescribed conditionsnecessary to safely maintain the rated insulation level, protecting the equipment against external influencesand providing a high degree of protection to personnel
3.2
manufacturer
organization that is responsible for the design of the enclosure and the production of the gas-insulatedswitchgear
Note 1 to entry: ln this standard, this is the switchgear manufacturer.
3.3
founder
organization that produces the raw casting of the enclosure
3.4
design pressure
pressure, expressed in relative terms (gauge), used to determine the thickness of the enclosure
Note 1 to entry: lt is at least equal to the maximum pressure in the enclosure at the highest temperature that the gasused for insulation can reach under specified maximum service conditions.
3.5
design temperature
design temperature of an enclosure
maximum temperature that the enclosures can reach under specified maximum service conditions[SOURCE:EN 62271-203:2012,3.112]
Note 1 to entry: This is generally the upper limit of ambient air temperature increased by the temperature rise due tothe flow of rated normal current.
Note 2 to entry: Solar radiation should be taken into account when it has a significant effect on the temperature of thegas and on the mechanical properties of materials. Similarly , the effects of low temperatures on the properties of somematerials should be considered.
3.6
design stress
maximum permissible stress on the enclosure imposed by conditions of operation, environment or test thatdetermine the (material) characteristics of an enclosure
3.7
normal load
load whose occurrence and level can be planned or predicted
3.8
exceptional load
load whose probability of occurrence during the lifetime of product is very small or accidental
3.9alloy
substance having metallic properties and composed of two or more elements so combined that they cannotreadily be separated by physical means
[SOURCE: EN 12258-1:2012,2.2.1]
3.10
aluminium alloy
metallic substance in which aluminium predominates by mass and the other elements exceed 1% of the totalcontent by weight
3.11
casting
product at or near finished shape, formed by solidification of the metal in a mould or a die
[SOURCE: EN 12258-1:2012,2.5.1]
3.12
melt
quantity of molten metal that has simultaneously undergone the same preparatory treatment in the furnacebefore the casting operation
[SOURCE: EN 12258-1:2012,4.1.3]3.13
weld defect
imperfections in metallic fusion welds
3.13.1
lack of fusion
lack of union between the weld metal and the parent material or between the successive layers of weld metal
[SOURCE:EN ISO 6520-1:2007, Reference No.401]
13.3.2
overlap
excessive weld metal covering the parent material surface but not fused to it
[SOURCE:EN ISO 6520-1:2007,Reference No.506]
3.13.3
undercut
irregular groove at a toe of a run in the parent material or in previously deposited weld metal