Amendment 1 - Explosive atmospheres - Part 6: Equipment protection by liquid immersion "o"

Amendement 1 - Atmosphères explosives - Partie 6: Protection du matériel par immersion dans le liquide "o"

General Information

Status
Published
Publication Date
23-Feb-2020
Current Stage
PPUB - Publication issued
Completion Date
24-Feb-2020
Ref Project

Buy Standard

Standard
IEC 60079-6:2015/AMD1:2020 - Amendment 1 - Explosive atmospheres - Part 6: Equipment protection by liquid immersion "o"
English and French language
14 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

IEC 60079-6
Edition 4.0 2020-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
A MENDMENT 1
AM ENDEMENT 1
Explosive atmospheres –
Part 6: Equipment protection by liquid immersion "o"
Atmosphères explosives –
Partie 6: Protection du matériel par immersion dans le liquide "o"
IEC 60079-6:2015-02/AMD1:2020-02(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2020 IEC, Geneva, Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from

either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC

copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or

your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite

ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie

et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des

questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez

les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC

The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes

International Standards for all electrical, electronic and related technologies.
About IEC publications

The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the

latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org

The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,

variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English

committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.

and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary

details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and

once a month by email. French extracted from the Terms and definitions clause of

IEC publications issued between 2002 and 2015. Some

IEC Customer Service Centre - webstore.iec.ch/csc entries have been collected from earlier publications of IEC

If you wish to give us your feedback on this publication or TC 37, 77, 86 and CISPR.

need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC

La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des

Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC

Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la

plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - Electropedia - www.electropedia.org

webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au

La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en

en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans

comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire

projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary

Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais

Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et définitions des

Disponible en ligne et une fois par mois par email. publications IEC parues entre 2002 et 2015. Plus certaines

entrées antérieures extraites des publications des CE 37, 77,
Service Clients - webstore.iec.ch/csc 86 et CISPR de l'IEC.
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
---------------------- Page: 2 ----------------------
IEC 60079-6
Edition 4.0 2020-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
A MENDMENT 1
AM ENDEMENT 1
Explosive atmospheres –
Part 6: Equipment protection by liquid immersion "o"
Atmosphères explosives –
Partie 6: Protection du matériel par immersion dans le liquide "o"
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-7866-6

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: 3 ----------------------
– 2 – IEC 60079-6:2015/AMD1:2020
 IEC 2020
FOREWORD

This amendment has been prepared by IEC technical committee 31: Equipment for explosive

atmospheres.
The text of this amendment is based on the following documents:
FDIS Report on voting
31/1517/FDIS 31/1526/RVD

Full information on the voting for the approval of this amendment can be found in the report

on voting indicated in the above table.

The committee has decided that the contents of this amendment and the base publication will

remain unchanged until the stability date indicated on the IEC website 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.
_____________
1 Scope
Delete the Note.
Add, after the fourth paragraph of Clause 1, the following new text:

Additionally, for Level of Protection "oc", Annex D applies where the rated voltage exceeds

15 kV AC RMS or DC and up to 245 kV AC RMS or DC.

Annex D applies specifically to liquid immersed transformers and reactors, and other liquid

immersed equipment such as swivels for off-shore platforms, power regulators, tap changers

and earthing/switching resistors.
2 Normative references
Add the following new references:
IEC 60071 (all parts), Insulation co-ordination

IEC 60076-3, Power transformers – Part 3: Insulation levels, dielectric tests and external

clearances in air

IEC 60079-1, Explosive atmospheres – Part 1: Equipment protection by flameproof enclosures

"d"
---------------------- Page: 4 ----------------------
IEC 60079-6:2015/AMD1:2020 – 3 –
 IEC 2020

IEC 60079-2, Explosive atmospheres – Part 2: Equipment protection by pressurized enclosure

"p"

IEC 60079-33, Explosive atmospheres – Part 33: Equipment protection by special protection

's'
IEC 60137, Insulated bushings for alternating voltages above 1000 V

IEC 62770, Fluids for electrotechnical applications – Unused natural esters for transformers

and similar electrical equipment
3 Terms and definitions
Add the following new terms and definitions:
3.11
oil-immersed swivel for HV connections

oil filled equipment to transfer power with coupling between two parts enabling one to revolve

and the other to remain stationary (fixed)
3.12
oil-immersed earthing resistor
equipment intended for system neutral earthing
3.13
oil-immersed switching resistor
equipment intended for inrush current limitation
---------------------- Page: 5 ----------------------
– 4 – IEC 60079-6:2015/AMD1:2020
 IEC 2020
Insert the following new Annex D after Annex C:
Annex D
(normative)
Supplementary requirements for electrical equipment
with Level of Protection "oc" for voltages greater than 15 kV
and up to and including 245 kV
D.1 General

Annex D supplements and modifies the requirements of this document. Subclauses 4.3, 4.4

and 4.6 do not apply to equipment covered by this Annex.

The voltage of explosion protected electrical equipment was limited for Level of Protection

"oc" up to 15 kV RMS AC or DC. Application of higher voltages exists to supply offshore

plants that are a long distance from the coast. Voltage levels up to 245 kV AC or DC are

RMS

needed to allow power transmission up to some hundred kilometres from shore to offshore or

between locations on shore/offshore. This Annex can be applied to liquid immersed

transformers, reactors, power regulators, tap changers and other liquid immersed HV

electrical equipment without dedicated IEC standards such as oil-immersed swivels for HV

connections, oil-immersed earthing resistors and oil-immersed switching resistors.

D.2 Additional requirements
D.2.1 Safety devices

For Level of Protection "oc", the requirements in 4.7.3 for Level of Protection "ob" apply for

equipment or components according to this Annex.
Each individual liquid filled compartment shall have its own safety devices.

A pressure relief device shall be provided that automatically disconnects the power when the

pressure relief device activates. The electrical equipment or system associated with the

pressure relief device to activate the automatic disconnection shall be suitable for EPL Gc. If

the pressure relief device itself is not directed downward a guide system, e.g. a pipe, shall be

provided. The dimensioning of this guide system shall not compromise the functionality of the

pressure relief.
D.2.2 Protective liquid specification

In addition to 5.1, natural ester insulating liquids in accordance with IEC 62770 may be used

in higher voltage equipment along with the insulating liquids already identified in this

document.

NOTE Natural ester liquids per IEC 62770 are proven up to 245 kV considering the ambient temperature

limitation.
D.2.3 Liquid immersion depth

Instead of Table 2, the required minimum liquid immersion depths necessary shall be

specified by the manufacturer and verified by high voltage tests as specified in D.4.7. The

tests shall be done with the minimum liquid level.
---------------------- Page: 6 ----------------------
IEC 60079-6:2015/AMD1:2020 – 5 –
 IEC 2020
D.2.4 Connections

Cables for field wiring connections greater than 15 kV shall be shielded to mitigate external

arcs and sparks caused by an external dielectric field. All HV cables above 15 kV shall be

armoured and shielded. Considerations shall be made to avoid circulating currents and

external arcs and sparks during energizing operation (Refer to the requirements of

IEC 60079-0 for circulating currents in enclosures).

The termination of the HV cable may be within enclosures using other Types of Protection

such as flameproof “d”, pressurization “p” or special protection “s”.

In the case of an enclosure in accordance with IEC 60079-1 Level of Protection “db” the

interface to the liquid immersion shall withstand the overpressure test of IEC 60079-1.

Termination in pressurized enclosures in accordance with IEC 60079-2 shall be Level of

Protection “pxb” or “pzc”.
Special protection “s” shall be in accordance with IEC 60079-33.
When bushings are used, the requirements of IEC 60137 apply.
D.2.5 On-load tap-changer (OLTC)

The on-load tap-changer shall be of type which does not produce arcs and sparks during

switching.
DC switching is not permitted.

NOTE OLTC according IEC 60214 can make switching operations up to several MVA/phase without sparking in

liquid when vacuum tap changers are applied. In a vacuum tap changer current switching takes place inside a

closed vacuum bottle and the current is limited by transition resistor or reactor during the switching.

D.2.6 Containment solutions

The liquid containment enclosure shall be sealed from the ambient environment in accordance

with 4.5.2.
Unsealed enclosures of 4.5.3 are not permitted.

NOTE 1 Sealing can be achieved by diaphragm/bladder/bag in conservator tank between the liquid and air or by

closed gas cushion (usually nitrogen) or by flexible fully filled tank (flexible corrugations or radiators).

NOTE 2 Because mineral oil, esters and silicone oil are hygroscopic, a sealed design in HV liquid insulated

equipment is considered as the only practical choice to increase maintenance intervals and reduce failure risks.

Expansion vessels with membrane are considered sealed.
D.2.7 Routine tests
D.2.7.1 Dielectric tests

Transformers and reactors test methods and voltages are given in IEC 60076-3. Test voltages

for transformers may be applied to other oil-immersed HV equipment or IEC 60071 may be

applied where there is no industrial standard for the type of equipment.
The following routine dielectric tests apply:

a) The test for phase to earth shall be conducted in accordance with the requirements of

IEC 60076-3 or IEC 60071.

b) The test for phase to phase shall be conducted in accordance with the requirements of

IEC 60076-3.
---------------------- Page: 7 ----------------------
– 6 – IEC 60079-6:2015/AMD1:2020
 IEC 2020

c) The test of partial discharge measurement for long duration with pre-stress voltage and

measurement level shall be conducted in accordance with IEC 60076-3. The acceptance

criteria shall be applied.

d) The test for lightning impulse given in IEC 60076-3 is applicable for transformers and

reactors,
...

Questions, Comments and Discussion

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