Power frequency overvoltage protective devices (POPs) for household and similar applications (IEC 63052:2019 + COR1:2019)

This document applies to devices for power frequency overvoltage protection (hereafter referred to as "POP") for household and similar uses, with a rated frequency of 50 Hz, 60 Hz or 50/60 Hz, with rated voltage not exceeding 230 V AC (between phase and neutral), and with rated current not exceeding 63 A, either consisting of a functional unit in combination with a main protective device (MPD), or as one single device having opening means able to open the protected circuit in specified conditions. The main protective device is a circuit-breaker, an RCCB or an RCBO. NOTE 1 A POP, as one single device, is not a protective device to be used for automatic disconnection of the supply within the meaning specified in IEC 60364-4-41. POPs are intended for use in an environment with pollution degree 2 and overvoltage category III. Devices for POPs are suitable for isolation. POPs can be designed as a POP unit assembled to or integrated in a main protective device by the manufacturer or as an assembly of a main protective device mechanically or electrically coupled on site with the POP unit, or as one single POP having opening means able to open the protected circuit in specified conditions. POPs are intended to mitigate the effects of power frequency overvoltages between a phase and neutral conductor (e.g. caused by loss of a neutral conductor in the three-phase supply upstream of the POP) for downstream equipment by opening the protected circuit when an overvoltage between phase and neutral is detected. NOTE 2 In this context, the verb "mitigate" means that the POP will provide protection in most cases of power frequency overvoltages. POPs intended for monitoring one line-to-neutral conductor voltage can be used between two-phase conductors in a phase-to-phase electrical supply system not exceeding 230 V if both conductors are switched and declared as such by the manufacturer. POPs according to this document are suitable for use in an IT system provided all active conductors are switched. This document does not apply to protection against common mode overvoltages. This document does not apply to surge protective devices.

Schutzeinrichtungen gegen netzfrequente Überspannungen für Hausinstallationen und für ähnliche Anwendungen (POP) (IEC 63052:2019 + COR1:2019)

Dispositifs de protection contre les surtensions à fréquence industrielle (POP) pour les applications domestiques et similaires (IEC 63052:2019 + COR1:2019)

Močnostna frekvenčna prenapetostna zaščitna naprava (POP) za gospodinjsko in podobno uporabo (IEC 63052:2019 + COR1:2019)

General Information

Status
Published
Publication Date
24-Oct-2021
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
30-Aug-2021
Due Date
04-Nov-2021
Completion Date
25-Oct-2021

Relations

Buy Standard

Standard
EN IEC 63052:2021
English language
124 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 63052:2021
01-december-2021
Nadomešča:
SIST EN 50550:2011
SIST EN 50550:2011/A1:2014
SIST EN 50550:2011/AC:2012
Močnostna frekvenčna prenapetostna zaščitna naprava (POP) za gospodinjsko in
podobno uporabo (IEC 63052:2019 + COR1:2019)
Power frequency overvoltage protective devices (POPs) for household and similar
applications (IEC 63052:2019 + COR1:2019)
Schutzeinrichtungen gegen netzfrequente Überspannungen für Hausinstallationen und
für ähnliche Anwendungen (POP) (IEC 63052:2019 + COR1:2019)
Dispositifs de protection contre les surtensions à fréquence industrielle (POP) pour les
applications domestiques et similaires (IEC 63052:2019 + COR1:2019)
Ta slovenski standard je istoveten z: EN IEC 63052:2021
ICS:
29.120.50 Varovalke in druga Fuses and other overcurrent
nadtokovna zaščita protection devices
SIST EN IEC 63052:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN IEC 63052:2021

---------------------- Page: 2 ----------------------
SIST EN IEC 63052:2021


EUROPEAN STANDARD EN IEC 63052

NORME EUROPÉENNE

EUROPÄISCHE NORM
August 2021
ICS 29.120.50 Supersedes EN 50550:2011 and all of its amendments
and corrigenda (if any)
English Version
Power frequency overvoltage protective devices (POPs) for
household and similar applications
(IEC 63052:2019 + COR1:2019)
Dispositifs de protection contre les surtensions à fréquence Schutzeinrichtungen gegen netzfrequente Überspannungen
industrielle (POP) pour les applications domestiques et für Hausinstallationen und für ähnliche Anwendungen
similaires (POP)
(IEC 63052:2019 + COR1:2019) (IEC 63052:2019 + COR1:2019)
This European Standard was approved by CENELEC on 2019-09-25. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, 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: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 63052:2021 E

---------------------- Page: 3 ----------------------
SIST EN IEC 63052:2021
EN IEC 63052:2021 (E)
European foreword
The text of document 23E/1131/FDIS, future edition 1 of IEC 63052, prepared by SC 23E "Circuit-
breakers and similar equipment for household use" of IEC/TC 23 "Electrical accessories" was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 63052:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-02-20
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-08-20
document have to be withdrawn
This document supersedes EN 50550:2011 and all of its amendments and corrigenda (if any).
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.
This document has been prepared under a Standardization Request given to CENELEC by the
European Commission and the European Free Trade Association, and supports essential
requirements of EU Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZZ, which is an integral
part of this document.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 63052:2019 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 60060-2 NOTE Harmonized as EN 60060-2
IEC 60068-2-30:2005 NOTE Harmonized as EN 60068-2-30:2005 (not modified)
IEC 60068-3-4:2001 NOTE Harmonized as EN 60068-3-4:2002 (not modified)
IEC 60085 NOTE Harmonized as EN 60085
IEC 60112 NOTE Harmonized as EN IEC 60112
IEC 60364-4-41 NOTE Harmonized as HD 60364-4-41
IEC 60364-4-44 NOTE Harmonized as HD 60364-4-444
2

---------------------- Page: 4 ----------------------
SIST EN IEC 63052:2021
EN IEC 63052:2021 (E)
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  Where 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 60065 (mod) 2014 Audio, video and similar electronic EN 60065 2014
apparatus - Safety requirements
- -  + A11 2017
IEC 60269 series Low-voltage fuses EN 60269 series
IEC 60364 series Low-voltage electrical installations HD 60364 series
IEC 60384-14 2013 Fixed capacitors for use in electronic EN 60384-14 2013
equipment - Part 14: Sectional
specification - Fixed capacitors for
electromagnetic interference suppression
and connection to the supply mains
+ A1 2016  + A1 2016
IEC 60417 -  Graphical symbols for use on equipment -
IEC 60529 1989 Degrees of protection provided by EN 60529 1991
enclosures (IP Code)
+ A1 1999 + A1 2000
+ A2 2013 + A2 2013
IEC 60664-1 2007 Insulation coordination for equipment EN 60664-1 2007
within low-voltage systems - Part 1:
Principles, requirements and tests
IEC 60664-3 2016 Insulation coordination for equipment EN 60664-3 2017
within low-voltage systems - Part 3: Use of
coating, potting or moulding for protection
against pollution
IEC 60695-2-10 2013 Fire hazard testing - Part 2-10: EN 60695-2-10 2013
Glowing/hot-wire based test methods -
Glow-wire apparatus and common test
procedure
IEC 60695-2-11 2014 Fire hazard testing - Part 2-11: EN 60695-2-11 2014
Glowing/hot-wire based test methods -
Glow-wire flammability test method for
end-products (GWEPT)
3

---------------------- Page: 5 ----------------------
SIST EN IEC 63052:2021
EN IEC 63052:2021 (E)
Publication Year Title EN/HD Year
IEC 60898-1 (mod) 2015 Electrical accessories - Circuit-breakers EN 60898-1 2019
for overcurrent protection for household
and similar installations - Part 1: Circuit-
breakers for a.c. operation
IEC 60898-2 2016 Electrical accessories - Circuit-breakers EN 60898-2 2006
for overcurrent protection for household
and similar installations - Part 2: Circuit-
breakers for AC and DC operation
IEC 61000-4-2 2008 Electromagnetic compatibility (EMC) - Part EN 61000-4-2 2009
4-2: Testing and measurement techniques
- Electrostatic discharge immunity test
IEC 61000-4-3 2020 Electromagnetic compatibility (EMC) - Part EN 61004-4-3 2020
4-3: Testing and measurement techniques
- Radiated, radio-frequency,
electromagnetic field immunity test
IEC 61000-4-4 2012 Electromagnetic compatibility (EMC) - Part EN 61000-4-4 2012
4-4: Testing and measurement techniques
- Electrical fast transient/burst immunity
test
IEC 61000-4-5 2014 Electromagnetic compatibility (EMC) - Part EN 61000-4-5 2014
4-5: Testing and measurement techniques
- Surge immunity test
+ A1 2017 + A1 2017
IEC 61000-4-6 2013 Electromagnetic compatibility (EMC) - Part EN 61000-4-6 2014
4-6: Testing and measurement techniques
- Immunity to conducted disturbances,
induced by radio-frequency fields
IEC 61000-4-16 2015 Electromagnetic compatibility (EMC) - Part EN 61000-4-16 2016
4-16: Testing and measurement
techniques - Test for immunity to
conducted, common mode disturbances in
the frequency range 0 Hz to 150 kHz
IEC 61000-6-3 2020 Electromagnetic compatibility (EMC) - Part EN 61000-6-3 2007
6-3: Generic standards - Emission
standard for residential, commercial and
light-industrial environments
- - + A1 2011
IEC 61008-1 (mod) 2010 Residual current operated circuit-breakers EN 61008-1 2012
without integral overcurrent protection for
household and similar uses (RCCBs) -
Part 1: General rules
+ A1 (mod) 2012  + A1 2014
+ A2 (mod) 2013  + A2 2014
- -  + A11 2015
- -  + A12 2017
4

---------------------- Page: 6 ----------------------
SIST EN IEC 63052:2021
EN IEC 63052:2021 (E)
Publication Year Title EN/HD Year
IEC 61009-1 (mod) 2010 Residual current operated circuit-breakers EN 61009-1 2012
with integral overcurrent protection for
household and similar uses (RCBOs) -
Part 1: General rules
+ A1 (mod) 2012  + A1 2014
+ A2 (mod) 2013  + A2 2014
- -  + A11 2015
- -  + A12 2016
IEC 61249-2 series Materials for printed boards and other EN 61249-2 series
interconnecting structures
IEC 61543 1995 Residual current-operated protective EN 61543 1995
devices (RCDs) for household and similar
use - Electromagnetic compatibility
+ A1 2004  - -
- -  + corrigendum 1997
Dec.
- -  + A11 2003
- -  + A12 2005
+ A2 2005  + A2 2006
IEC 61558-1 2017 EN IEC 61558-1 2019
IEC 61558-2 series Safety of power transformers, power EN 61558-2 series
supplies, reactors and similar products
IEC 62423 2009 Type F and type B residual current EN 62423 2012
operated circuit-breakers with and without
integral overcurrent protection for
household and similar uses
IEC 62873-2 2016 Residual current operated circuit-breakers - -
for household and similar use – Part 2:
Residual current devices (RCDs) –
Vocabulary
IEC 62873-3-1 2016 Residual current operated circuit-breakers - -
for household and similar use – Part 3-1:
Particular requirements for RCDs with
screwless-type terminals for external
copper conductors
IEC 62873-3-2 2016 Residual current operated circuit-breakers - -
for household and similar use – Part 3-2:
Particular requirements for RCDs with flat
quick-connect terminations
IEC 62873-3-3 2016 Residual current operated circuit-breakers - -
for household and similar use – Part 3-3:
Specific requirements for RCDs with
screw-type terminals for external untreated
aluminium conductors and with aluminium
screw-type terminals for use with copper
or with aluminium conductors
5

---------------------- Page: 7 ----------------------
SIST EN IEC 63052:2021
EN IEC 63052:2021 (E)
Publication Year Title EN/HD Year
ISO 306 2014 Plastics - Thermoplastic materials - EN ISO 306 2014
Determination of Vicat softening
temperature (VST)
CISPR 14-1 2016 Electromagnetic compatibility - EN 55014-1 2017
Requirements for household appliances,
electric tools and similar apparatus - Part
1: Emission
CISPR 32 2015  Electromagnetic compatibility of EN 55032 2015
multimedia equipment - Emission
requirements
+ A1 2019 - -
- - + A11 2020

6

---------------------- Page: 8 ----------------------
SIST EN IEC 63052:2021
EN IEC 63052:2021 (E)
Annex ZZ
(informative)

Relationship between this European standard and the safety
objectives of Directive 2014/35/EU [2014 OJ L96] aimed to be
covered
This European Standard has been prepared under a Commission’s standardization request relating to
harmonized standards in the field of the Low Voltage Directive, M/511, to provide one voluntary means
of conforming to safety objectives of Directive 2014/35/EU of the European Parliament and of the
Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the
making available on the market of electrical equipment designed for use within certain voltage limits
[2014 OJ L96].
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZZ.1 confers, within the limits of
the scope of this standard, a presumption of conformity with the corresponding safety objectives of
that Directive, and associated EFTA regulations.
Table ZZ.1 — Correspondence between this European standard and Annex I of Directive
2014/35/EU [2014 OJ L96]
Clause(s) / sub-clause(s)
Safety objectives of Directive
Remarks / Notes
2014/35/EU
of this EN
(1)(a) 1, 2, 3, 4, 5, 6, 9.3
(1)(b) 8.1, 8.2, 9.4, 9.5
(1)(c) 7, 8.6, 8.12, 8.13, 9.1, 9.2, 9.9,
9.15, 9.16
(2) (a) 8.3, 8.7, 8.13, 9.6, 9.10, 9.16
(2) (b) 8.5, 8.6, 8.7, 8.8, , 8.14, 9.8,
9.9, 9.10, 9.11, 9.17, Annex A,
Annex C
(2) (c) 8.2.2, 9.1.1
(2) (d) 8.2.3, 8.4, 9.7, 9.19, 9.20, 9.7,
Annex B
(3) (a) 8.9, 9.12
(3) (b) 8.10, 8.11, 8.15, 9.13, 9.14,
9.18
(3) (c) 8.8, 9.11, Annex C
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European
standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2 — Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.

7

---------------------- Page: 9 ----------------------
SIST EN IEC 63052:2021

---------------------- Page: 10 ----------------------
SIST EN IEC 63052:2021




IEC 63052

®


Edition 1.0 2019-08




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Power frequency overvoltage protection devices (POPs) for household and

similar applications




Dispositifs de protection contre les surtensions à fréquence industrielle (POP)

pour les applications domestiques et similaires
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 29.120.50 ISBN 978-2-8322-7268-8




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 11 ----------------------
SIST EN IEC 63052:2021
– 2 – IEC 63052:2019 © IEC 2019
CONTENTS
FOREWORD . 8
1 Scope . 10
2 Normative references . 10
3 Terms, definitions and abbreviated terms . 12
3.1 Terms and definitions. 12
3.2 Abbreviated terms . 14
4 Classification . 15
4.1 According to the method of construction . 15
4.2 According to the number of monitored line-to-neutral conductor voltages . 15
4.3 According to the method of mounting . 15
5 Characteristics of POPs . 15
5.1 Summary of characteristics . 15
5.2 Rated quantities and other characteristics. 16
5.2.1 Rated voltage . 16
5.2.2 Rated current (I ) . 16
n
5.2.3 Rated frequency . 16
5.2.4 Rated making and breaking capacity (I ) . 16
m
5.2.5 Rated making and breaking capacity on one pole (I ) . 16
m1
5.3 Standard and preferred values . 16
5.3.1 Preferred values of rated voltage (U ) . 16
n
5.3.2 Preferred values of rated current (I ) . 17
n
5.3.3 Preferred values of rated frequency . 17
5.3.4 Minimum value of the rated making and breaking capacity (I ) . 17
m
5.3.5 Minimum value of the rated making and breaking capacity on one pole
(I ) . 17
m1
5.3.6 Standard and preferred values of the rated conditional short-circuit
current (I ) and standard and preferred values of the rated conditional
nc
short-circuit current for one pole (I ) . 17
nc1
5.3.7 Limit values of the break times and non-actuating times . 18
5.3.8 Standard value of rated impulse withstand voltage (U ) . 18
imp
5.4 Coordination with short-circuit protective devices (SCPDs) . 18
5.4.1 General . 18
5.4.2 Rated conditional short-circuit current (I ) and rated conditional short-
nc
circuit on one pole (I ) . 19
nc1
5.4.3 Operating characteristics of opening means for POPs according to 4.1.4. 19
6 Marking and other product information . 19
6.1 Marking . 19
6.2 Additional marking for POPs according to 4.1.4 . 22
6.2.1 Marking of POPs . 22
6.2.2 Instructions for wiring and operation . 22
7 Standard conditions for operation in service and for installation . 22
7.1 Standard conditions . 22
7.2 Conditions of installation . 23
7.3 Pollution degree . 23
8 Requirements for construction and operation . 23
8.1 General . 23

---------------------- Page: 12 ----------------------
SIST EN IEC 63052:2021
IEC 63052:2019 © IEC 2019 – 3 –
8.2 Mechanical design . 24
8.2.1 General . 24
8.2.2 Mechanism . 25
8.2.3 Clearances and creepage distances . 26
8.2.4 Screws, current-carrying parts and connections . 29
8.2.5 Terminals for external conductors . 30
8.3 Protection against electric shock . 32
8.4 Dielectric properties and isolating capability. 33
8.5 Temperature-rise . 33
8.5.1 Temperature-rise limits . 33
8.5.2 Ambient air temperature . 34
8.6 Operating characteristics . 34
8.6.1 Operating characteristics of the MPD part . 34
8.6.2 Operating characteristics of the POP . 34
8.7 Mechanical and electrical endurance . 34
8.8 Performance at short-circuit currents . 35
8.9 Resistance to mechanical shock and impact . 35
8.10 Resistance to heat . 35
8.11 Resistance to abnormal heat and to fire . 35
8.12 Safety performance of overstressed POPs . 35
8.13 Behaviour of POPs in case of current surges caused by impulse voltages . 35
8.14 Reliability . 35
8.15 Electromagnetic compatibility (EMC) . 35
9 Testing procedure. 36
9.1 General . 36
9.1.1 General testing procedure for the different type of POPs . 36
9.1.2 Characteristics of POPs are checked by means of type tests . 37
9.1.3 For certification purposes, type tests are carried out in test sequences . 38
9.2 Test conditions . 38
9.3 Test of indelibility of marking . 39
9.4 Test of reliability of screws, current-carrying parts and connections . 39
9.5 Test of reliability of terminals for external conductors . 41
9.6 Verification of protection against electric shock . 42
9.7 Test of dielectric properties . 42
9.7.1 Resistance to humidity. 42
9.7.2 Insulation resistance of the main circuit . 43
9.7.3 Dielectric strength of the main circuit . 44
9.7.4 Insulation resistance and dielectric strength of auxiliary circuits . 44
9.7.5 Capability of control circuits connected to the main circuit withstanding

high DC voltages due to insulation measurements . 45
9.7.6 Verification of impulse withstand voltages and of leakage current across
open contacts . 46
9.8 Test of temperature-rise . 48
9.8.1 Ambient air temperature . 48
9.8.2 Test procedure . 48
9.8.3 Measurement of the temperature of parts . 49
9.8.4 Temperature-rise of a part . 49
9.9 Verification of the operating characteristics . 49
9.9.1 Test circuit . 49

---------------------- Page: 13 ----------------------
SIST EN IEC 63052:2021
– 4 – IEC 63052:2019 © IEC 2019
9.9.2 Off-load characteristic tests with sinusoidal alternating voltages at the
reference temperature of 20 °C ± 5 °C . 49
9.9.3 Test of the effect of the ambient air temperature on the operating
characteristics . 50
9.10 Verification of mechanical and electrical endurance . 50
9.10.1 General test conditions . 50
9.10.2 Test procedure . 50
9.10.3 Additional test for POP according to 4.1.4 . 51
9.10.4 Condition of the POP after the test . 51
9.11 Verification of the behaviour of the POP under short-circuit conditions . 52
9.11.1 General . 52
9.11.2 Short-circuit tests for POPs according to 4.1.4 . 52
9.12 Verification of resistance to mechanical shock and impact . 59
9.12.1 Mechanical shock . 59
9.12.2 Mechanical impact . 60
9.13 Test of resistance to heat . 62
9.13.1 Test on complete product . 62
9.13.2 Ball pressure test. 63
9.14 Test of resistance to abnormal heat and to fire . 64
9.15 Test of safety performance of overstressed POPs . 65
9.16 Verification of behaviour of POPs in case of current surges caused by
impulse voltages . 65
9.16.1 General . 65
9.16.2 Verification of behaviour at surge currents up to 3 000 A (8/20 µs surge
current test) . 66
9.17 Verification of ageing of electronic components . 66
9.18 Electromagnetic compatibility (EMC) . 67
9.18.1 General . 67
9.18.2 EMC tests covered by other clauses/subclauses of the present

document . 67
9.18.3
...

Questions, Comments and Discussion

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