EN IEC 60076-22-8:2021

Power transformers - Part 22-8: Power transformer and reactor fittings - Devices suitable for use in communication networks

This part of IEC 60076-22 applies to a selection of accessories and fittings mounted on liquid immersed power transformers according to IEC 60076-1 and reactors according to IEC 60076-6 with or without conservator for indoor or outdoor installation. It outlines the operation requirements specific to each device as well as the data made available to the communication network and the type and routine test to be performed. The communication network is not part of the scope of this standard.

Leistungstransformatoren - Teil 22-8: Zubehörteile von Leistungstransformatoren und Drosselspulen - Einrichtungen mit Eignung zur Anwendung in Kommunikationsnetzen

Transformateurs de puissance - Partie 22-8: Accessoires pour transformateurs de puissance et bobines d'inductance - Dispositifs compatibles avec les réseaux de communication

L'IEC 60076-22:2021 s'applique à un ensemble d'accessoires installés sur des transformateurs de puissance immergés dans un liquide conformes à l'IEC 60076-1 et sur des bobines d'inductance conformes à l'IEC 60076-6 avec ou sans conservateur, destinés aux installations intérieures ou extérieures. Elle spécifie les exigences de fonctionnement spécifiques à chaque dispositif, les données mises à la disposition du réseau de communication, ainsi que les essais de type et les essais individuels de série à réaliser. Le réseau de communication ne relève pas du domaine d'application du présent document.

Močnostni transformatorji - 22-8. del: Močnostni transformatorji in dušilke - Naprave, primerne za uporabo v komunikacijskih omrežjih

General Information

• Status: Published
• Publication Date: 12-Aug-2021
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: CLC/TC 14 - Power transformers
• Drafting Committee: IEC/TC 14 - IEC_TC_14
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 13-Aug-2021
• Due Date: 18-Jan-2024
• Completion Date: 13-Aug-2021
• Ref Project: SIST EN IEC 60076-22-8:2021 - Power transformers - Part 22-8: Power transformer and reactor fittings - Devices suitable for use in communication networks

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 60076-22-8:2021
01-november-2021
Močnostni transformatorji - 22-8. del: Močnostni transformatorji in dušilke -
Naprave, primerne za uporabo v komunikacijskih omrežjih

Power transformers - Part 22-8: Power transformer and reactor fittings - Devices suitable

for use in communication networks
Ta slovenski standard je istoveten z: EN IEC 60076-22-8:2021
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
SIST EN IEC 60076-22-8:2021 en

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

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SIST EN IEC 60076-22-8:2021
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SIST EN IEC 60076-22-8:2021
EUROPEAN STANDARD EN IEC 60076-22-8
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2021
ICS 29.180
English Version
Power transformers - Part 22-8: Power transformer and reactor
fittings - Devices suitable for use in communication networks
(IEC 60076-22-8:2021)

Transformateurs de puissance - Partie 22-8: Accessoires Leistungstransformatoren - Teil 22-8: Zubehörteile von

pour transformateurs de puissance et bobines d'inductance Leistungstransformatoren und Drosselspulen -

- Dispositifs compatibles avec les réseaux de Einrichtungen mit Eignung zur Anwendung in

communication Kommunikationsnetzen
(IEC 60076-22-8:2021) (IEC 60076-22-8:2021)

This European Standard was approved by CENELEC on 2021-07-20. 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 60076-22-8:2021 E
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SIST EN IEC 60076-22-8:2021
EN IEC 60076-22-8:2021 (E)
European foreword

The text of document 14/1057/CDV, future edition 1 of IEC 60076-22-8, prepared by IEC/TC 14

"Power transformers" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC

as EN IEC 60076-22-8:2021.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2022-04-20

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2024-07-20

document have to be withdrawn

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.

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 60076-22-8:2021 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 60076-1 NOTE Harmonized as EN 60076-1
IEC 60296 NOTE Harmonized as EN IEC 60296
ISO 9001 NOTE Harmonized as EN ISO 9001
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SIST EN IEC 60076-22-8:2021
EN IEC 60076-22-8:2021 (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 60076-22-1 2019 Power transformers - Part 22-1: Power EN IEC 60076-22-1 2019
transformer and reactor fittings -
Protective devices
IEC 60076-22-7 - Power transformers - Part 22-7: Power EN IEC 60076-22-7 -
transformer and reactor fittings -
Accessories and fittings
IEC 61000-6-4 - Electromagnetic compatibility (EMC) - EN IEC 61000-6-4 -
Part 6-4: Generic standards - Emission
standard for industrial environments
IEC 61000-6-5 - Electromagnetic compatibility (EMC) - EN 61000-6-5 -
Part 6-5: Generic standards - Immunity for
equipment used in power station and
substation environment
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SIST EN IEC 60076-22-8:2021
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SIST EN IEC 60076-22-8:2021
IEC 60076-22-8
Edition 1.0 2021-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Power transformers –
Part 22-8: Power transformer and reactor fittings – Devices suitable for use in
communication networks
Transformateurs de puissance –
Partie 22-8: Accessoires pour transformateurs de puissance et bobines
d'inductance – Dispositifs compatibles avec les réseaux de communication
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.180 ISBN 978-2-8322-9861-9

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
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SIST EN IEC 60076-22-8:2021
– 2 – IEC 60076-22-8:2021 © IEC 2021
CONTENTS

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

INTRODUCTION ..................................................................................................................... 6

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

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

3 Terms and definitions ...................................................................................................... 7

4 General requirements ...................................................................................................... 8

4.1 Standard compliance .............................................................................................. 8

4.2 Modbus requirements ............................................................................................. 8

4.3 Type tests for EMC ................................................................................................. 9

4.3.1 Emission .......................................................................................................... 9

4.3.2 Immunity .......................................................................................................... 9

4.4 Additional requirements .......................................................................................... 9

4.4.1 Terminals ........................................................................................................ 9

4.4.2 Signal and control ports ................................................................................... 9

4.5 Cybersecurity ........................................................................................................ 10

5 Power supply ................................................................................................................. 10

6 Devices ......................................................................................................................... 10

6.1 Gas and liquid actuated relays (Buchholz relays) .................................................. 10

6.1.1 General ......................................................................................................... 10

6.1.2 4 mA to 20 mA output .................................................................................... 10

6.1.3 Modbus output ............................................................................................... 10

6.1.4 Tests ............................................................................................................. 11

6.2 Protective relays for hermetically sealed liquid-immersed equipment .................... 11

6.2.1 General ......................................................................................................... 11

6.2.2 4 mA to 20 mA output .................................................................................... 11

6.2.3 Modbus output ............................................................................................... 11

6.2.4 Tests ............................................................................................................. 11

6.3 Direct reading dial type liquid level indicators ....................................................... 12

6.3.1 General ......................................................................................................... 12

6.3.2 4 mA to 20 mA output .................................................................................... 12

6.3.3 Modbus output ............................................................................................... 12

6.3.4 Tests ............................................................................................................. 12

6.4 Pressure relief devices with continuous pressure monitoring ................................. 12

6.4.1 General ......................................................................................................... 12

6.4.2 4 mA to 20 mA output .................................................................................... 13

6.4.3 Modbus output ............................................................................................... 13

6.4.4 Routine test ................................................................................................... 13

6.5 Electronic pressure and pressure rise monitoring systems .................................... 13

6.5.1 General ......................................................................................................... 13

6.5.2 4 mA to 20 mA output .................................................................................... 13

6.5.3 Modbus output ............................................................................................... 13

6.5.4 Tests ............................................................................................................. 14

6.6 Direct reading mechanical dial type liquid temperature indicators .......................... 15

6.6.1 General ......................................................................................................... 15

6.6.2 4 mA to 20 mA output .................................................................................... 15

6.6.3 Modbus output ............................................................................................... 15

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6.6.4 Routine tests ................................................................................................. 15

6.7 Direct reading mechanical dial type winding temperature indicators ...................... 15

6.7.1 General ......................................................................................................... 15

6.7.2 4 mA to 20 mA output .................................................................................... 15

6.7.3 Modbus output ............................................................................................... 16

6.7.4 Routine tests ................................................................................................. 16

6.8 Electrical and electronic liquid temperature measuring devices ............................. 16

6.8.1 General ......................................................................................................... 16

6.8.2 4 mA to 20 mA output .................................................................................... 16

6.8.3 Modbus output ............................................................................................... 16

6.8.4 Tests ............................................................................................................. 16

6.9 Electrical and electronic winding temperature simulating devices .......................... 17

6.9.1 General ......................................................................................................... 17

6.9.2 4 mA to 20 mA output .................................................................................... 17

6.9.3 Modbus output ............................................................................................... 17

6.9.4 Tests ............................................................................................................. 17

6.10 Dehydrating breathers, self-regenerating types ..................................................... 18

6.10.1 General ......................................................................................................... 18

6.10.2 4 mA to 20 mA output .................................................................................... 18

6.10.3 Modbus output ............................................................................................... 19

6.10.4 Routine tests ................................................................................................. 19

6.11 Dissolved gas analysis devices (DGA devices) ..................................................... 19

6.11.1 General ......................................................................................................... 19

6.11.2 4 mA to 20 mA output .................................................................................... 19

6.11.3 Modbus output ............................................................................................... 20

6.11.4 Tests ............................................................................................................. 20

Bibliography .......................................................................................................................... 21

Figure 1 – Pressure rise response curves for oil (left) or gas (right) space applications ........ 14

Table 1 – Summary of Modbus parameters ............................................................................. 9

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SIST EN IEC 60076-22-8:2021
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
POWER TRANSFORMERS –
Part 22-8: Power transformer and reactor fittings –
Devices suitable for use in communication networks
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.

IEC 60076-22-8 has been prepared by IEC technical committee 14: Power transformers. It is

an International Standard.
The text of this International Standard is based on the following documents:
CDV Report on voting
14/1057/CDV 14/1062A/RVC

Full information on the voting for its approval can be found in the report on voting indicated in

the above table.
The language used for the development of this International Standard is English.
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SIST EN IEC 60076-22-8:2021
IEC 60076-22-8:2021 © IEC 2021 – 5 –

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in

accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available

at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are

described in greater detail at www.iec.ch/standardsdev/publications.

A list of all parts in the IEC 60076 series, published under the general title Power transformers,

can be found on the IEC website.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under webstore.iec.ch in the data related to the

specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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INTRODUCTION

Under the title "Power transformer and reactor fittings – Devices suitable for use in

communication networks", IEC 60076-22-8 covers an exhaustive selection of devices that are

currently used in communication networks.
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SIST EN IEC 60076-22-8:2021
IEC 60076-22-8:2021 © IEC 2021 – 7 –
POWER TRANSFORMERS –
Part 22-8: Power transformer and reactor fittings –
Devices suitable for use in communication networks
1 Scope

This part of IEC 60076-22 applies to a selection of accessories and fittings mounted on liquid

immersed power transformers according to IEC 60076-1 and reactors according to IEC 60076-6

with or without conservator for indoor or outdoor installation.

It outlines the operation requirements specific to each device as well as the data made available

to the communication network and the type and routine test to be performed.
The communication network is not part of the scope of this document.
2 Normative references

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.

IEC 60076-22-1:2019, Power transformers – Part 22-1: Power transformer and reactor fittings

– Protective devices

IEC 60076-22-7, Power transformers – Part 22-7: Power transformer and reactor fittings –

Accessories and fittings

IEC 61000-6-4, Electromagnetic compatibility (EMC) – Part 6-4: Generic standards – Emission

standard for industrial environments

IEC 61000-6-5, Electromagnetic compatibility (EMC) – Part 6-5: Generic standards – Immunity

for equipment used in power station and substation environment
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following

addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
communication network
collection of terminal nodes

Note 1 to entry: Links are connected to enable communication between the devices.

Note 2 to entry: Means of transmission of signals in one direction between two points.

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3.2
communication protocol

defined set of procedures adopted to ensure communication between sets of processes which

exist within the same layer of a hierarchy of layers

[SOURCE: IEC 60050-716-1:1995, 716-01-17, modified – In the term "communication" has

been added.]
3.3
Modbus protocol
serial communications protocol

Note 1 to entry: Modbus is a de facto standard communication protocol and it is now a commonly available means

of connecting industrial electronic devices.

Note 2 to entry: Modbus is often used to connect a supervisory computer with a remote terminal unit (RTU) in

supervisory control and data acquisition (SCADA) systems.
3.4
4 mA to 20 mA output
point-to-point or multi-drop circuit

Note 1 to entry: This type of circuit sends an analogue signal from 4 mA to 20 mA that represents the extremes of

the process variable.
3.5
electrical and electronic liquid temperature measuring device
device measuring the liquid temperature using electrical or electronic sensors
3.6
electrical and electronic winding temperature simulating device
device simulating the winding temperature using electrical or electronic sensors
3.7
dissolved gas analysis device
DGA device

device used to measure the dissolved gas concentration within a liquid on a regular time basis

Note 1 to entry: This device usually also measures relative humidity and temperature of the liquid.

Note 2 to entry: This note applies to the French language only.
4 General requirements
4.1 Standard compliance
All devices shall comply with IEC 60076-22-1 and IEC 60076-22-7 as applicable.

All devices shall be subject to type tests to verify the electromagnetic compatibility.

4.2 Modbus requirements

If not otherwise specified, Modbus output shall be of the RTU type. The manufacturer shall

provide all information about the Modbus connection needed by the customer to configure the

connection.
The digital information shall be available via an RS485 port.
Table 1 shows a summary of Modbus parameters.
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Table 1 – Summary of Modbus parameters
Parameters Possible values Code Default values
Address Add 1 to 247 001 to 247 NA
4 800 bits/s 4,8 19 200 bits/s
Baud rate 9 600 bits/s 9,6 or alternatively
19 200 bits/s 19,2 9 600 bits/s
8 databits, uneven parity, 1 stop bit 8O1
8E1
8 databits, even parity, 1 stop bit 8E1
Number, parity
or alternatively
and stop bits
8 databits, no parity, 1 stop bit 8N1
8N1
8 databits, no parity, 2 stop bits 8N2
On special request TCP/IP can be provided.
4.3 Type tests for EMC
4.3.1 Emission

The equipment shall comply with IEC 61000-6-4, measured as table top arrangement, at 3 m

with all doors and caps closed. All relevant tests shall be performed.
4.3.2 Immunity

The equipment shall comply with IEC 61000-6-5, interface 4 for both substation and power

station. All relevant tests shall be performed.
4.4 Additional requirements
4.4.1 Terminals

In addition to the terminals defined in IEC 60076-22-1, the device shall be equipped with a

minimum of 2 additional terminals for each 4 mA to 20 mA output and 3 for each Modbus in and

output and 2 additional terminals for power supply if the 4 mA to 20 mA outputs are active.

Unless otherwise specified, the 4 mA to 20 mA output shall be active.

The terminal block shall be suitable for cables of 1,5 mm , unless otherwise specified.

By agreement between manufacturer and purchaser the device can be fitted with plug and

socket.
4.4.2 Signal and control ports
4.4.2.1 4 mA to 20 mA

Maximum cable length between the device and the data acquisition system shall be 30 m.

Maximum resistance to be applied shall be 450 Ω.
4.4.2.2 Modbus

Maximum cable length between the device and the data acquisition system shall be 30 m.

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4.5 Cybersecurity

Electronic devices covered by this document are not linked to Internet or other external

networks. Therefore there are no requirements for cybersecurity in this document.

If on special request the device is connected to Internet, cybersecurity issues shall be

addressed.
5 Power supply

Preferred power supply for the communication part of the device is 24 V DC. The tolerance on

the rated voltage shall be ±20 % permanently. The residual alternative voltage component shall

be less than 2 % of the voltage peak to peak.

If the device (for example self-regenerating dehydrating breather) needs for its operation

(beside the communication) an AC or DC power supply, then the communication power can be

derived from the operation power supply.
6 Devices
6.1 Gas and liquid actuated relays (Buchholz relays)
6.1.1 General

The volume of gas is monitored continuously by an additional component embedded in the

Buchholz relay.

Upon customer requirements, the information can be analogue given via a 4 mA to 20 mA output

and/or digital via the Modbus protocol.

The performance of the contacts specified in IEC 60076-22-1 shall not be affected by the

requirements detailed in this Subclause 6.1.1.
6.1.2 4 mA to 20 mA output
The 4 mA to 20 mA output monitors the gas volume accumulation.

Therefore the 4 mA shall correspond to the Buchholz relay completely full of liquid (no gas) and

the 20 mA shall correspond to the Buchholz relay completely empty of liquid (full of gas).

The manufacturer shall state a transfer function of the 4 mA to 20 mA output signal to the

volume of the accumulated gas.

If the gas accumulation from zero to the point before gas escapes into the pipework towards

the conservator can be expected to be linear within ±5 %, then the manufacturer may declare,

as a simplification, only the value of the accumulated gas volume before any gas escapes into

the pipework towards the conservator and the corresponding value of mA.
6.1.3 Modbus output
The digital output by Modbus shall transmit at least the gas volume monitored,
...