SIST EN 62271-207:2012

High-voltage switchgear and controlgear - Part 207: Seismic qualification for gas-insulated switchgear assemblies for rated voltages above 52 kV (IEC 62271-207:2012)

IEC 62271-207:2012 applies to gas-insulated switchgear assemblies for alternating current of rated voltages above 52 kV for indoor and outdoor installations, including their supporting structure. This second edition of IEC 62271-207 cancels and replaces the first edition published in 2007. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:   - modification of the minimum voltage rating from 72,5 kV to above 52 kV;  - harmonisation of qualification procedures for GIS with IEEE 693:2005 Annex A and P by modifying the response spectra;  - modification of the test procedures;   - addition of criteria of allowed stresses;  - addition of dynamic analysis CQC.

Hochspannungs-Schaltgeräte und -Schaltanlagen - Teil 207: Erdbebenqualifikation für gasisolierte Schaltgerätekombinationen mit Bemessungsspannungen über 52 kV (IEC 62271-207:2012)

Appareillage à haute tension - Partie 207: Qualification sismique pour ensembles d'appareillages à isolation gazeuse pour des niveaux de tension assignée supérieurs à 52 kV (CEI 62271-207:2012)

La CEI 62271-207:2012 s'applique aux ensembles d'appareillages à isolation gazeuse à courant alternatif de tension assignée supérieure à 52 kV, installés à l'intérieur ou à l'extérieur, en incluant leurs châssis-supports. Cette deuxième édition de la CEI 62271-207 annule et remplace la première édition publiée en 2007. Elle constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:  - modification de la tension assignée minimale, passant d'une valeur de 72,5 kV à une valeur supérieure à 52 kV;  - harmonisation des procédures de qualification pour ensembles d'appareillage à isolation gazeuse avec les Annexes A et P de l'IEEE 693:2005 en modifiant les spectres de réponse;   - modification des procédures d'essai;  - ajout de critères des contraintes autorisées;   - ajout d'une analyse dynamique CQC.

Visokonapetosne stikalne naprave - 207. del: Seizmična (potresna) kvalifikacija plinsko izoliranih stikalnih sestavov za naznačene vrednosti nad 52 kV (IEC 62271-207:2012)

Ta del standarda IEC 62271 se nanaša na plinsko izolirane stikalne sestave za izmenični tok naznačenih vrednosti nad 52 kV za notranje in zunanje naprave, vključno z njihovo nosilno konstrukcijo. Za stikalne naprave, na primer odklopnike s komoro pod napetostjo, se uporablja standard IEC/TR 62271-300. Navodila o medsebojnih vplivih nosilne konstrukcije in zemlje/temeljev so v dodatku B. Seizmična kvalifikacija stikalnih sestavov upošteva preskušanje značilnih stikalnih sestavov skupaj z metodami analize. Vključeni so medsebojni vplivi med neposredno nameščeno pomožno in nadzorno opremo ter stikalnimi sestavi. Seizmična kvalifikacija stikalnih sestavov se izvede le na zahtevo.

General Information

• Status: Published
• Publication Date: 24-Sep-2012
• ICS: 29.130.10 - High voltage switchgear and controlgear
• Technical Committee: SKA - Switchgear and control gear
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 30-Aug-2012
• Due Date: 04-Nov-2012
• Completion Date: 25-Sep-2012
• Ref Project: EN 62271-207:2012 - High-voltage switchgear and controlgear - Part 207: Seismic qualification for gas-insulated switchgear assemblies for rated voltages above 52 kV

Relations

• Replaces: SIST EN 62271-207:2008 - High-voltage switchgear and controlgear -- Part 207: Seismic qualification for gas-insulated switchgear assemblies for rated voltages above 52 kV
• Effective Date: 01-Oct-2012
• Replaced By: SIST EN IEC 62271-207:2024 - High-voltage switchgear and controlgear - Part 207: Seismic qualification for gas-insulated switchgear assemblies, metal enclosed and solid-insulation enclosed switchgear for rated voltages above 1 kV (IEC 62271-207:2023)
• Effective Date: 01-Feb-2024
• Revised: SIST EN 62271-207:2008 - High-voltage switchgear and controlgear -- Part 207: Seismic qualification for gas-insulated switchgear assemblies for rated voltages above 52 kV
• Effective Date: 06-May-2014

Overview

EN 62271-207:2012 (CLC adoption of IEC 62271-207:2012) specifies seismic qualification requirements for gas‑insulated switchgear (GIS) assemblies for alternating current at rated voltages above 52 kV. This second edition (2012) supersedes the 2007 edition and applies to indoor and outdoor installations including supporting structures. The standard defines test and analysis methods to verify the mechanical integrity and functional performance of high‑voltage switchgear under seismic excitation.

Key Topics

• Scope and applicability: GIS assemblies for rated voltages above 52 kV; qualification performed on request; includes interactions with directly mounted auxiliary and control equipment.
• Qualification approaches: Combined physical testing and numerical analysis (time‑history, modal/spectrum analyses) and rules for static coefficient analysis.
• Test procedures: Mounting, measurement methods, frequency range, test directions and sequence, and characterization of the test set.
• Required response spectra (RRS): Harmonisation with IEEE 693:2005 Annex A and P by modifying response spectra used for qualification; separate spectra for moderate and high seismic severities.
• Evaluation criteria: Combination of stresses, functional acceptance criteria, allowable stress limits and documentation/reporting requirements.
• Technical additions in 2012 edition:
  • Minimum voltage rating changed from 72.5 kV to above 52 kV
  • Modified test procedures and response spectra harmonised with IEEE 693
  • Addition of criteria of allowed stresses
  • Inclusion of dynamic analysis using Complete Quadratic Combination (CQC)

Applications

EN 62271-207 is used to:

• Validate seismic resilience of GIS designs and factory assemblies.
• Define type‑test and qualification protocols for new switchgear products.
• Guide installation, procurement and specification requirements for seismically active regions.
• Support safety and continuity planning for utilities, substations and critical infrastructure.

Who uses this standard

• GIS and high‑voltage switchgear manufacturers
• Substation and power system design engineers
• Independent testing laboratories and certification bodies
• Electrical utilities and asset owners specifying seismic performance
• Procurement teams and compliance officers preparing technical specifications

Related standards

• IEC/EN 62271‑1 (Common specifications for high‑voltage switchgear)
• IEC/EN 62271‑203 (Gas‑insulated metal‑enclosed switchgear >52 kV)
• IEEE 693:2005 (Seismic design of substations) - harmonisation influence
• Environmental and seismic test references: IEC 60068 series

EN 62271-207:2012 provides a practical, harmonised framework for demonstrating GIS seismic adequacy - essential for ensuring reliable high‑voltage service in earthquake-prone areas.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2012
1DGRPHãþD
SIST EN 62271-207:2008
9LVRNRQDSHWRVQHVWLNDOQHQDSUDYHGHO6HL]PLþQDSRWUHVQDNYDOLILNDFLMD
SOLQVNRL]ROLUDQLKVWLNDOQLKVHVWDYRY]DQD]QDþHQHYUHGQRVWLQDGN9,(&

High-voltage switchgear and controlgear - Part 207: Seismic qualification for gas-
insulated switchgear assemblies for rated voltages above 52 kV (IEC 62271-207:2012)
Hochspannungs-Schaltgeräte und -Schaltanlagen - Teil 207: Erdbebenqualifikation für
gasisolierte Schaltgerätekombinationen mit Bemessungsspannungen über 52 kV (IEC
62271-207:2012)
Appareillage à haute tension - Partie 207: Qualification sismique pour ensembles
d'appareillages à isolation gazeuse pour des niveaux de tension assignée supérieurs à
52 kV (CEI 62271-207:2012)
Ta slovenski standard je istoveten z: EN 62271-207:2012
ICS:
29.130.10 Visokonapetostne stikalne in High voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 62271-207
NORME EUROPÉENNE
July 2012
EUROPÄISCHE NORM
ICS 29.130.10 Supersedes EN 62271-207:2007

English version
High-voltage switchgear and controlgear -
Part 207: Seismic qualification for gas-insulated switchgear assemblies
for rated voltages above 52 kV
(IEC 62271-207:2012)
Appareillage à haute tension -  Hochspannungs-Schaltgeräte und -
Partie 207: Qualification sismique pour Schaltanlagen -
ensembles d'appareillages à isolation Teil 207: Erdbebenqualifikation für
gazeuse pour des niveaux de tension gasisolierte Schaltgerätekombinationen
assignée supérieurs à 52 kV mit Bemessungsspannungen über 52 kV
(CEI 62271-207:2012) (IEC 62271-207:2012)

This European Standard was approved by CENELEC on 2012-06-01. 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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62271-207:2012 E
Foreword
The text of document 17C/542/FDIS, future edition 2 of IEC 62271-207, prepared by SC 17C “High-
voltage switchgear and controlgear assemblies”, of IEC/TC 17 "Switchgear and controlgear", was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 62271-207:2012.
The following dates are fixed:
(dop) 2013-03-01
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2015-06-01
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 62271-207:2007.

EN 62271-207:2007:
- modification of the minimum voltage rating from 72,5 kV to above 52 kV;
- harmonisation of qualification procedures for GIS with IEEE 693:2005 Annex A and P by modifying
the response spectra;
- modification of the test procedures;
- addition of criteria of allowed stresses;
- addition of dynamic analysis CQC.

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 62271-207:2012 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 61462 NOTE Harmonized as EN 61462.
IEC 62155 NOTE Harmonized as EN 62155.
IEC 62231 NOTE Harmonized as EN 62231.

- 3 - EN 62271-207:2012
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
IEC 60068-2-47 - Environmental testing - EN 60068-2-47 -
Part 2-47: Tests - Mounting of specimens for
vibration, impact and similar dynamic tests

IEC 60068-2-57 - Environmental testing - EN 60068-2-57 -
Part 2-57: Tests - Test Ff: Vibration - Time-
history method
IEC 60068-3-3 1991 Environmental testing - EN 60068-3-3 1993
Part 3: Guidance - Seismic test methods
for equipments
IEC 62271-1 - High-voltage switchgear and controlgear - EN 62271-1 -
Part 1: Common specifications
IEC 62271-203 - High-voltage switchgear and controlgear - EN 62271-203 -
Part 203: Gas-insulated metal-enclosed
switchgear for rated voltages above 52 kV

IEC 62271-207 ®
Edition 2.0 2012-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
High-voltage switchgear and controlgear –

Part 207: Seismic qualification for gas-insulated switchgear assemblies for rated

voltages above 52 kV
Appareillage à haute tension –

Partie 207: Qualification sismique pour ensembles d'appareillages à isolation

gazeuse pour des niveaux de tension assignée supérieurs à 52 kV

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX R
ICS 29.130.10 ISBN 978-2-88912-060-4

– 2 – 62271-207  IEC:2012
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Seismic qualification requirements . 6
4.1 General . 6
4.2 Qualification levels . 6
5 Test procedures for qualification . 6
5.1 General . 6
5.2 Mounting . 7
5.3 Measurements . 7
5.4 Frequency range . 7
5.5 Test severity . 7
5.5.1 General . 7
5.5.2 Parameters for time-history excitation . 9
5.5.3 Test directions . 9
5.5.4 Test sequence . 9
6 Qualification by combined test and numerical analysis . 10
6.1 General . 10
6.2 Dynamic and functional data . 11
6.3 Numerical analysis . 11
6.3.1 General . 11
6.3.2 Numerical analysis by the acceleration time-history method . 11
6.3.3 Modal and spectrum analysis using the required response spectrum
(RRS) . 11
6.3.4 Static coefficient analysis . 12
7 Evaluation of the seismic qualification . 12
7.1 Combination of stresses . 12
7.2 Acceptance criteria for the seismic waveform . 13
7.3 Functional evaluation of the test results . 13
7.4 Allowable stresses . 13
8 Documentation . 13
8.1 Information for seismic qualification. 13
8.2 Test report . 14
8.3 Analysis report . 14
Annex A (normative) Characterisation of the test-set . 15
Annex B (informative) Criteria for seismic adequacy of gas-insulated metal-enclosed
switchgear . 17
Bibliography . 19

Figure 1 – Required response spectrum (RRS) for qualification level moderate . 8
Figure 2 – Required response spectrum (RRS) for qualification level high . 9
Figure A.1 – Monogram for the determination of equivalent damping ratio . 16

Table 1 – Seismic qualification levels for switchgear assemblies – Horizontal severities . 6

62271-207  IEC:2012 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
______________
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 207: Seismic qualification for gas-insulated
switchgear assemblies for rated voltages above 52 kV

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62271-207 has been prepared by subcommittee 17C: High-voltage
switchgear and controlgear assemblies, of IEC technical committee 17: Switchgear and
controlgear.
This second edition of IEC 62271-207 cancels and replaces the first edition published in 2007.
It constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– modification of the minimum voltage rating from 72,5 kV to above 52 kV;
– harmonisation of qualification procedures for GIS with IEEE 693:2005 Annex A and P by
modifying the response spectra;
– modification of the test procedures;
– addition of criteria of allowed stresses;

– 4 – 62271-207  IEC:2012
– addition of dynamic analysis CQC.
The text of this standard is based on the following documents:
FDIS Report on voting
17C/542/FDIS 17C/549/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 62271 series, under the general title High-voltage switchgear
and controlgear, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
olours which are considered to be useful for the correct
that it contains c
understanding of its contents. Users should therefore print this document using a
colour printer.
62271-207  IEC:2012 – 5 –
HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR –

Part 207: Seismic qualification for gas-insulated
switchgear assemblies for rated voltages above 52 kV

1 Scope
This part of IEC 62271 applies to gas-insulated switchgear assemblies for alternating current
of rated voltages above 52 kV for indoor and outdoor installations, including their supporting
structure.
For switchgear devices, e.g. live tank circuit breakers, IEC/TR 62271-300 is applicable.
Guidance on interactions between the supporting structure and the soil / foundations is
provided in Annex B.
The seismic qualification of the switchgear assemblies takes into account testing of typical
switchgear assemblies combined with methods of analysis. Mutual interaction between
directly mounted auxiliary and control equipment and switchgear assemblies are covered.
The seismic qualification of switchgear assemblies is only performed upon request.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-2-47, Environmental testing – Part 2-47: Tests – Mounting of specimens for
vibration, impact and similar dynamic tests
IEC 60068-2-57, Environmental testing – Part 2-57: Tests – Test Ff: Vibration – Time-history
method
IEC 60068-3-3:1991, Environmental testing – Part 3: Guidance – Seismic test methods for
equipments
IEC 62271-1, High-voltage switchgear and controlgear – Part 1: Common specifications
IEC 62271-203, High-voltage switchgear and controlgear – Part 203: Gas-insulated metal-
enclosed switchgear for rated voltages above 52 kV
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60068-3-3,
IEC 62271-203 and IEC 62271-1 apply.

– 6 – 62271-207  IEC:2012
4 Seismic qualification requirements
4.1 General
The seismic qualification shall demonstrate the ability of the switchgear assemblies to
withstand seismic stress. It may be proofed by test or by a combination of test and analysis.
No failure on the enclosure and the main circuits as well as on the control and auxiliary
circuit, including the relevant supporting structures, shall occur.
For ductile material, minor permanent deformations are acceptable provided that they do not
impair the functionality of the equipment. The equipment shall properly operate after the
seismic event as defined in 7.2 and 7.3.
4.2 Qualification levels
The qualification has to be done on one of the recommended levels of Table 1. For vertical
severities the direction factor is 0,5.
No qualification is required for low seismic level as far as construction practice and seismic
construction practice comply with the state of the art.
Other qualification levels which consist in requirements from the customer that can be based
on specific investigation at site or regulations in national standard, taking into account for
example the type of soil, soil structure interaction, building response, and elevation may be
used.
Table 1 – Seismic qualification levels for switchgear assemblies –
Horizontal severities
Qualification Required response Zero period acceleration
level spectrum (RRS) (ZPA)
m/s
High Figure 1 5
Moderate Figure 2 2,5
Low --- 1
5 Test procedures for qualification
5.1 General
The test procedure for qualification of a test-set shall be in accordance with IEC 60068-3-3.
The qualification shall be carried out on a representative test-set.
NOTE 1 For GIS it is not possible to test a complete substation on a shake table, because of the size and weight.
Numerical analysis is always needed to give information about the seismic qualification.
The seismic test needs to be carried out under the rated filling pressure of the GIS.
The rated filling pressure in the GIS is required to test under realistic situations. Nevertheless
test laboratories for seismic testing need adequate safety measures. Test laboratories are
available in USA, Europe and Japan.
During the seismic testing no operation of the circuit breaker is necessary.

62271-207  IEC:2012 – 7 –
NOTE 2 The circuit breaker operates much faster than any earthquake excitation and therefore a switching
operation has no practical impact on the test result.
If the auxiliary and control equipment or other parts of the equipment are dynamically
uncoupled, they may be qualified independently.
If a test-set cannot be tested with its supporting structure (e.g., due to its size), the dynamic
contribution of the structure shall be determined by analysis and taken into account in the
test.
The time-history test method is to be preferred, since it more closely simulates actual
conditions, particularly if the behaviour of the test-set is not linear. The test method shall be in
accordance with IEC 60068-2-57.
5.2 Mounting
The test-set shall be mounted as in service including dampers (if any).
The horizontal orientation of the test-set shall be in the direction of excitation acting along its
two main orthogonal axes.
Any fixations or connections that are required only the convenience of testing must not affect
the dynamic behaviour of the test-set.
The method of mounting of the test-set shall be documented and shall include a description of
any interposing fixtures and connections. IEC 60068-2-47 provides guidance.
5.3 Measurements
Measurements shall be performed in accordance with IEC 60068-3-3 and shall include
– vibration motion of components where maximum deflections and significant relative
displacements are expected;
– strains of critical elements (e.g. bushings, flanges, enclosures and support structures).
5.4 Frequency range
Frequency range shall be 0,5 Hz to 33 Hz. The frequency range is applied to the resonant
frequency search test and the generation of artificial earthquake wave.
5.5 Test severity
5.5.1 General
The test severity shall be chosen in accordance with Clause 4.
The recommended required response spectra are given in Figures 1 and 2 for the different
seismic qualification levels. The curves relate to 2 %, 5 %, 10 % of the switchgear
assemblies. If damping factor is unknown, 2 % damping is applied.
Spectra for different damping values may be obtained by linear interpolation.

– 8 – 62271-207  IEC:2012
0,9
d = 2
0,8
0,7
d = 5
0,6
d = 10
0,5
0,4
0,3
0,2
0,1
0,2        0,4   0,6 1          2         4     6 10        20        40      100
f  (Hz)
IEC  694/12
Spectral Accelerations, S (g), for Frequencies, f (Hz):
a
S = 0,572 β f for 0,0 ≤ f ≤ 1,1
a
S = 0,625 β  for 1,1 ≤ f ≤ 8,0
a
S = (6,6 β – 2,64) / f – 0,2 β + 0,33 for 8,0 ≤ f ≤ 33
a
S = 0,25  for f > 33
a
β = (3,21 – 0,68 ln(d)) / 2,115 6, where d is the percent damping (2, 5, 10, etc.) and d ≤ 20 %
Figure 1 – Required response spectrum (RRS) for qualification level moderate

S  (g)
a
62271-207  IEC:2012 – 9 –
1,8
d = 2
1,6
1,4
d = 5
1,2
d = 10
1,0
0,8
0,6
0,4
0,2
0,1        0,2        0,4   0,6 1          2         4     6
10        2
...