Wind turbines - Part 26-1: Time-based availability for wind turbine generating systems

IEC 61400-26-1:2011(E) defines generic information categories to which fractions of time can be assigned for a wind turbine generating system (WTGS) considering internal and external conditions based on fraction of time and specifying the following: - generic information categories of a WTGS considering availability and other performance indicators; - information category priority in order to discriminate between concurrent categories; - entry and exit point for each information category in order to allocate designation of time; - informative annexes providing various examples.

Windenergieanlagen - Teil 26-1: Zeitbasierte Verfügbarkeit von Windenergieanlagen

Éoliennes - Partie 26-1: Disponibilité temporelle pour les systèmes de production d'énergie éolienne

Vetrne turbine - 26-1. del: Časovna razpoložljivost, ki temelji na proizvodnih sistemih vetrnih elektrarn (IEC/TS 61400-26-1:2011)

Ta del standarda IEC 61400 opredeljuje generične kategorije informacij, za katere je mogoče določiti deleže časa za sistem za proizvodnjo vetrne turbine (WTGS) glede na notranje in zunanje pogoje, ki temeljijo na deležu časa in določajo naslednje:
• generične kategorije informacij sistema za proizvodnjo vetrne turbine ob upoštevanju razpoložljivosti in drugih indikatorjev delovanja;
• prioriteto kategorije informacij, da bi razlikovali med sočasnimi kategorijami;
• vstopno in izhodno točko za vsako kategorijo informacij, da se določi čas
• informativni dodatki, ki vključujejo:
– primere izbirnih kategorij informacij,
– primere algoritmov za poročanje o razpoložljivosti in indikatorje delovanja,
– primere scenarijev uporabe.

General Information

Status
Published
Publication Date
31-Aug-2017
Technical Committee
Current Stage
6060 - Document made available
Due Date
01-Sep-2017
Completion Date
01-Sep-2017

RELATIONS

Buy Standard

Technical specification
-TS CLC/TS 61400-26-1:2017 - BARVE na PDF-str od 50 do 58
English language
56 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST-TS CLC/TS 61400-26-1:2017
01-oktober-2017
9HWUQHWXUELQHGHOýDVRYQDUD]SRORåOMLYRVWNLWHPHOMLQDSURL]YRGQLK
VLVWHPLKYHWUQLKHOHNWUDUQ ,(&76

Wind turbines - Part 26-1: Time-based availability for wind turbine generating systems

(IEC/TS 61400-26-1:2011)

Windenergieanlagen - Teil 26-1: Zeitbasierte Verfügbarkeit von Windenergieanlagen

(IEC/TS 61400-26-1:2011)

Éoliennes - Partie 26-1: Disponibilité temporelle pour les systèmes de production

d'énergie éolienne (IEC/TS 61400-26-1:2011)
Ta slovenski standard je istoveten z: CLC/TS 61400-26-1:2017
ICS:
27.180 Vetrne elektrarne Wind turbine energy systems
SIST-TS CLC/TS 61400-26-1:2017 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
---------------------- Page: 2 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
TECHNICAL SPECIFICATION CLC/TS 61400-26-1
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
September 2017
ICS 27.180
English Version
Wind turbines -
Part 26-1: Time-based availability
for wind turbine generating systems
(IEC/TS 61400-26-1:2011)
Éoliennes - Windenergieanlagen -
Partie 26-1: Disponibilité temporelle Teil 26-1: Zeitbasierte Verfügbarkeit
pour les systèmes de production d'énergie éolienne von Windenergieanlagen
(IEC/TS 61400-26-1:2011) (IEC/TS 61400-26-1:2011)
This Technical Specification was approved by CENELEC on 2017-07-17.

CENELEC members are required to announce the existence of this TS in the same way as for an EN and to make the TS available promptly

at national level in an appropriate form. It is permissible to keep conflicting national standards in force.

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, Serbia, Slovakia, Slovenia, Spain, Sweden,

Switzerland, Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. CLC/TS 61400-26-1:2017 E
---------------------- Page: 3 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
CLC/TS 61400-26-1:2017
European foreword

This document (CLC/TS 61400-26-1:2017) consists of the text of IEC/TS 61400-26-1:2011 prepared

by IEC/TC 88 "Wind energy generation systems".

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice

The text of the International Standard IEC/TS 61400-26-1:2011 was approved by CENELEC as a

Technical Specification without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 61400-25-2:2006 NOTE Harmonized as EN 61400-25-2:2007 (not modified).
IEC 61400-25-3:2006 NOTE Harmonized as EN 61400-25-3:2007 (not modified).
IEC 61400-25-4:2008 NOTE Harmonized as EN 61400-25-4:2008 (not modified).
---------------------- Page: 4 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
CLC/TS 61400-26-1:2017
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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.

NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod),

the relevant EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is

available here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-415 1999 International Electrotechnical - -
Vocabulary - Part 415: Wind
turbine generator systems
IEC 61400-1 - Wind turbines - Part 1: Design EN 61400-1 -
requirements
---------------------- Page: 5 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
---------------------- Page: 6 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
IEC/TS 61400-26-1
Edition 1.0 2011-11
TECHNICAL
SPECIFICATION
colour
inside
Wind turbines –
Part 26-1: Time-based availability for wind turbine generating systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
ICS 27.180 ISBN 978-2-88912-780-1
® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 7 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
– 2 – TS 61400-26-1 © IEC:2011(E)
CONTENTS

FOREWORD ........................................................................................................................... 4

1 Scope ............................................................................................................................... 7

2 Normative references ....................................................................................................... 7

3 Terms, definitions and abbreviations ................................................................................ 7

3.1 Terms and definitions .............................................................................................. 7

3.2 Abbreviations .......................................................................................................... 8

4 Information model ............................................................................................................. 9

4.1 General ................................................................................................................... 9

4.2 Information categories ............................................................................................. 9

4.3 Limitations ............................................................................................................... 9

4.4 Information category priority .................................................................................. 11

5 INFORMATION AVAILABLE ........................................................................................... 12

5.1 OPERATIVE .......................................................................................................... 13

5.1.1 GENERATING ........................................................................................... 13

5.1.2 NON-GENERATING .................................................................................. 15

5.2 NON-OPERATIVE ................................................................................................. 20

5.2.1 SCHEDULED MAINTENANCE ................................................................... 21

5.2.2 PLANNED CORRECTIVE ACTION ............................................................ 22

5.2.3 FORCED OUTAGE .................................................................................... 23

5.2.4 SUSPENDED ............................................................................................ 24

5.3 FORCE MAJEURE ................................................................................................ 24

6 INFORMATION UNAVAILABLE ...................................................................................... 25

Annex A (informative) Optional information categories – examples ...................................... 27

Annex B (informative) Time based availability indicators – examples ................................... 40

Annex C (informative) Verification scenarios – examples ..................................................... 44

Bibliography .......................................................................................................................... 53

Figure 1 – Information category overview .............................................................................. 10

Figure 2 – Information category priority ................................................................................. 11

Figure 3 – INFORMATION AVAILABLE category .................................................................. 12

Figure 4 – OPERATIVE category .......................................................................................... 13

Figure 5 – GENERATING category ....................................................................................... 14

Figure 6 – FULL PERFORMANCE category .......................................................................... 14

Figure 7 – PARTIAL PERFORMANCE category .................................................................... 15

Figure 8 – NON GENERATING category ............................................................................... 16

Figure 9 – TECHNICAL STANDBY category ......................................................................... 17

Figure 10 – OUT OF ENVIRONMENTAL SPECIFICATION category ..................................... 18

Figure 11 – REQUESTED SHUTDOWN category .................................................................. 19

Figure 12 – OUT OF ELECTRICAL SPECIFICATION category .............................................. 20

Figure 13 – NON-OPERATIVE category ................................................................................ 21

Figure 14 – SCHEDULED MAINTENANCE category ............................................................. 22

Figure 15 – PLANNED CORRECTIVE ACTION category....................................................... 23

Figure 16 – FORCED OUTAGE category .............................................................................. 23

---------------------- Page: 8 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
TS 61400-26-1 © IEC:2011(E) – 3 –

Figure 17 – SUSPENDED category ....................................................................................... 24

Figure 18 – FORCE MAJEURE category ............................................................................... 25

Figure 19 – INFORMATION UNAVAILABLE category ............................................................ 26

Figure A.1 – Information category overview – mandatory and optional .................................. 28

Figure A.2 – Optional categories for PARTIAL PERFORMANCE ........................................... 29

Figure A.3 – Derated category .............................................................................................. 30

Figure A.4 – Degraded category ........................................................................................... 30

Figure A.5 – Optional categories for OUT OF ENVIRONMENTAL SPECIFICATION .............. 31

Figure A.6 – Calm winds category ......................................................................................... 32

Figure A.7 – Other environmental category ........................................................................... 33

Figure A.8 – Optional categories for NON-OPERATIVE ........................................................ 34

Figure A.9 – Optional categories for forced outage ............................................................... 35

Figure A.10 – Workflow breakdown structure ........................................................................ 36

Figure A.11 – Optional categories for SUSPENDED.............................................................. 38

Figure C.1 – Verification scenarios – time allocation to information categories ...................... 44

Figure C.2 – Verification scenarios – communication aspects ............................................... 45

Figure C.3 – Verification scenarios – partial operational aspects .......................................... 46

Figure C.4 – Verification scenarios – maintenance aspects ................................................... 47

Figure C.5 – Verification scenarios – operational aspects ..................................................... 49

Figure C.6 – Verification scenarios – grid / electrical network aspects .................................. 50

Figure C.7 – Verification scenarios – environmental aspects ................................................. 52

---------------------- Page: 9 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
– 4 – TS 61400-26-1 © IEC:2011(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WIND TURBINES –
Part 26-1: Time-based availability for wind turbine generating systems
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.

The main task of IEC technical committees is to prepare International Standards. In

exceptional circumstances, a technical committee may propose the publication of a technical

specification when

• the required support cannot be obtained for the publication of an International Standard,

despite repeated efforts, or

• The subject is still under technical development or where, for any other reason, there is

the future but no immediate possibility of an agreement on an International Standard.

Technical specifications are subject to review within three years of publication to decide

whether they can be transformed into International Standards.

IEC 61400-26-1, which is a technical specification, has been prepared by IEC technical

committee 88: Wind turbines.
---------------------- Page: 10 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
TS 61400-26-1 © IEC:2011(E) – 5 –
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
88/387/DTS 88/415/RVC

Full information on the voting for the approval of this technical specification 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 parts of the IEC 61400 series, under the general title Wind turbines, 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
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual edition of this document may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 11 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
– 6 – TS 61400-26-1 © IEC:2011(E)
INTRODUCTION

The intention of this technical specification is to define a common basis for exchange of

information on performance indicators between owners, utilities, lenders, operators,

manufacturers, consultants, regulatory bodies, certification bodies, insurance companies and

other stakeholders in the wind power generation business. This is achieved by providing an

information model specifying how time designations shall be split into information categories.

The information model forms the basis for allocation of time for reporting availability and

reliability indicators.

The technical specification defines generic terms of wind turbine systems and environmental

constraints in describing system and component availability, lifetime expectancy, repairs and

criteria for determining overhaul intervals. The specification defines terminology and generic

terms for reporting wind power based generating unit availability measurement. A generating

unit includes all equipment up to the termination point defined in the distribution code (grid

code) agreed between the generation party and the distribution / transmission party.

Availability measurements are concerned with fractions of time a unit is capable of providing

service, taking environmental aspects into account. Environmental aspects will be wind and

other weather conditions, as well as grid and substation conditions. The specification

furthermore defines terminology and terms for reporting performance indicators based on

power production or capacity. Mandatory information categories defined in the technical

specification are written in capital letters; optional information categories defined in the

technical specification are written in bold letters.

The project scope is accomplished by separating the technical specification into two parts:

• IEC/TS 61400-26-1 specifies terms for time based availability of a wind turbine

generating system;

• IEC/TS 61400-26-2 specifies terms for production based availability of a wind turbine

generating system.
---------------------- Page: 12 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
TS 61400-26-1 © IEC:2011(E) – 7 –
WIND TURBINES –
Part 26-1: Time-based availability for wind turbine generating systems
1 Scope

This part of IEC 61400 defines generic information categories to which fractions of time can

be assigned for a wind turbine generating system (WTGS) considering internal and external

conditions based on fraction of time and specifying the following:

• generic information categories of a WTGS considering availability and other performance

indicators;

• information category priority in order to discriminate between concurrent categories;

• entry and exit point for each information category in order to allocate designation of time

• informative annexes including:
– examples of optional information categories,
– examples of algorithms for reporting availability and performance indicators,
– examples of application scenarios.
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 60050-415:1999, International Electrotechnical Vocabulary – Part 415: Wind turbine

generator systems Available from: http://www.electropedia.org/
IEC 61400-1, Wind turbines – Design requirements
3 Terms, definitions and abbreviations

For the purposes of the present document, the following terms, definitions and abbreviations

apply, as well as the relevant terms and definitions contained in IEC 60050-415.
3.1 Terms and definitions
3.1.1
availability

fraction of a given operating period in which a WTGS is performing its intended services

within the design specification
3.1.2
design specifications

collection of precise and explicit information about requirements for a product design

It provides in-depth details about the functional and non-functional design requirements

including assumptions, constraints, performance, dimensions, weights, reliability and

standards. For example, specifications and design considerations given in IEC 61400-1 define

the process for producing design specifications for WTGS.
---------------------- Page: 13 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
– 8 – TS 61400-26-1 © IEC:2011(E)
3.1.3
external conditions

conditions outside of the WTGS that affect the operation of the WTGS, for example (i) out of

environmental specification and (ii) out of electrical specification
3.1.4
permanent storage

type of computer storage that keeps the data or its contents regardless of whether the power

is turned off or if the storage device is moved to another computer
The most commonly used permanent storage is the computer hard disk drive.
3.1.5
reliability

probability that a component part, equipment, or system will satisfactorily perform its intended

function under given circumstances for a specified period of time
3.1.6
repair

activity whereby components of a system are restored to a safe operating condition following

an unpredicted or unforeseen failure
3.1.7
retrofit

incorporation of new technology or new design parts resulting from an approved engineering

change to an already supplied item
3.1.8
total time
the total calendar time of the period selected
3.2 Abbreviations
IA Information available category
IAO Information available operative category
IAOG Information available operative generating category
IAOGFP Information available operative generating with full performance category

IAOGPP Information available operative generating with partial performance category

IAONG Information available operative non generating category

IAONGTS Information available operative non generating technical standby category

IAONGEN Information available operative non generating out of environmental
specification category
IAONGENC Information available operative non generating out of environmental
specification optional category calm winds
IAONGENO Information available operative non generating out of environmental
specification optional category other environmental

IAONGEL Information available operative non generating out of electrical specification

category

IAONGRS Information available operative non generating requested shutdown category

IAN Information available non operative category
IANSM Information available non operative scheduled maintenance category
IANPCA Information available non operative planned corrective action category
IANFO Information available non operative forced outage category
IANS Information available non operative suspended category
---------------------- Page: 14 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
TS 61400-26-1 © IEC:2011(E) – 9 –
IAFM Information available force majeure category
IU Information unavailable category
SCADA Supervisory control and data acquisition
WTGS Wind turbine generating system
TT Total time
4 Information model
4.1 General

The information model is comprised of different information categories. All calendar time shall

be distributed into these information categories.

Each information category has an associated entry point and exit point. The entry point

describes the criteria that have to be fulfilled to allocate time into a specific information

category. The exit point describes the criteria to be fulfilled to end time allocation to a specific

information category.

The information model is split into five levels and the hierarchy shall be understood from level

one to level five i.e. all attributes of overlaying information categories are inherited by

underlying information categories. The time designations are allocated at the lowest

mandatory level. Overlaying information categories shall contain the sum of the related

information categories on the underlying level. The information categories are introduced in

4.2.

In case entry conditions are fulfilled concurrently for two or more information categories, time

shall be assigned into the information category with the highest priority only. Information

category priorities are described in more details in 4.4.
4.2 Information categories

Information categories are counters for accumulation of time periods with specified attributes

defined for a WTGS for the purpose of exchange of information on availability.

Figure 1 is an overview of the information categories defined in this technical specification.

The information model includes four mandatory categories. The model also allows for

additional optional levels of information categories to provide the user with more detailed data.

Compliance with this technical specification requires designation of time periods into the

mandatory information categories defined in level 1 to level 4, as shown in Figure 1.

The optional information categories defined in level 5 are not required to be compliant with

this specification; they are included to allow users to customize reporting details to meet their

specific requirements. This specification imposes no limits on the number of optional

information categories or levels added by the individual users. The optional information

categories shown in Figure 1 are for illustrative purposes only and are described in Annex A.

All optional information categories shall be located on level 5 or higher in order to be

compliant with this technical specification.

Abbreviations for the various information categories are indicated in brackets with bold letters.

The abbreviations are defined in Clause 3.
4.3 Limitations

It is not in the scope of this technical specification to determine the method of information

acquisition.
---------------------- Page: 15 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
– 10 – TS 61400-26-1 © IEC:2011(E)
Information categories
Mandatory Mandatory Mandatory Mandatory Optional -
Level 1 Level 2 Level 3 Level 4 description
see Annex A
Level 5
FULL
PERFORMANCE
(IAOGFP)
PARTIAL Derated
PERFORMANCE
(IAOGPP)
Degraded
TECHNICAL
STANDBY
(IAONGTS)
OUT OF Calm winds
ENVIRONMENTAL
SPECIFICATION
Other
(IAONGEN)
environmental
REQUESTED
SHUTDOWN
(IAONGRS)
OUT OF
ELECTRICAL
SPECIFICATION
(IAONGEL)
SCHEDULED MAINTENANCE
(IANOSM)
Retrofit
PLANNED CORRECTIVE ACTION
(IANOPCA)
Upgrade
Other
corrective
action
Response
FORCED OUTAGE
(IANOFO) Diagnostic
Logistic
Failure repair
SUSPENDED Scheduled
(IANOS)
maintenance
Planned
corrective
action
Forced outage
FORCE MAJEURE
(IAFM)
INFORMATION UNAVAILABLE
(IU)
Figure 1 – Information category overview

The information categories are described in further details in Clause 5, Clause 6 and Annex A.

INFORMATION AVAILABLE
(IA)
NON-OPERATIVE
OPERATIVE
(IANO)
(IAO)
NON-GENERATING GENERATING
(IAONG) (IAOG)
---------------------- Page: 16 ----------------------
SIST-TS CLC/TS 61400-26-1:2017
TS 61400-26-1 © IEC:2011(E) – 11 –
4.4 Information category priority

Time present in the information categories shall be exclusive and continuous. In case the

conditions for allocating a time period to more than one information category are fulfille

...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.