prEN IEC 60567:2023

SLOVENSKI STANDARD
oSIST prEN IEC 60567:2023
01-april-2023
Z oljem polnjena električna oprema - Vzorčenje prostih plinov in analiziranje
prostih in raztopljenih plinov - Napotek
Oil-filled electrical equipment - Sampling of free gases and analysis of free and dissolved
gases - Guidance
Ölgefüllte elektrische Betriebsmittel - Probennahme von Gasen und Analyse freier und
gelöster Gase - Anleitung
Matériels électriques immergés - Echantillonnage de gaz et analyse des gaz libres et
dissous - Lignes directrices
Ta slovenski standard je istoveten z: prEN IEC 60567:2023
ICS:
29.040.10 Izolacijska olja Insulating oils
oSIST prEN IEC 60567:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 60567:2023

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oSIST prEN IEC 60567:2023
10/1192/CDV

COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60567 ED5
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-02-10 2023-05-05
SUPERSEDES DOCUMENTS:
10/1176/CD, 10/1191/CC

IEC TC 10 : FLUIDS FOR ELECTROTECHNICAL APPLICATIONS
SECRETARIAT: SECRETARY:
Italy Mr Massimo Pompili
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

TC 14, TC 20, SC 36A, TC 38, TC 112
Other TC/SCs are requested to indicate their interest, if any, in
this CDV to the secretary.
FUNCTIONS CONCERNED:
 EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for Vote
(CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.

This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of
• any relevant patent rights of which they are aware and to provide supporting documentation,
• any relevant “in some countries” clauses to be included should this proposal proceed. Recipients are reminded that the
enquiry stage is the final stage for submitting "in some countries" clauses. See AC/22/2007.

TITLE:
Oil-filled electrical equipment – Sampling of free gases and analysis of free and dissolved gases – Guidance –
Part 1: Mineral oils

PROPOSED STABILITY DATE: 2028

NOTE FROM TC/SC OFFICERS:


Copyright © 2022 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

® Registered trademark of the International Electrotechnical Commission

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CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 9
2 Normative references . 9
3 Sampling of gases from gas-collecting (Buchholz) relays . 10
3.1 General remarks. 10
3.2 Sampling of free gases by syringe . 10
3.2.1 Sampling equipment . 10
3.2.2 Sampling procedure. 11
3.3 Sampling of free gases by displacement of oil . 12
3.4 Sampling of free gases by vacuum . 13
3.5 Sampling of oil from oil filled equipment . 14
4 Labelling of gas samples . 14
5 Sampling, labelling and transferring of oil from oil-filled equipment . 14
5.1 Sampling and labelling of oil . 14
5.2 Transfer of oil for DGA analysis . 14
5.2.1 General . 14
5.2.2 Transfer from oil syringes . 14
5.2.3 Transfer from ampoules . 15
5.2.4 Transfer from flexible metal bottles . 15
5.2.5 Transfer from glass and rigid metal bottles . 15
6 Preparation of gas-in-oil standards . 15
6.1 General remark . 15
6.2 First method: preparation of a large volume of gas-in-oil standard . 15
6.2.1 Equipment . 15
6.2.2 Procedure . 16
6.2.3 Calculation . 18
6.3 Second method: preparation of gas-in-oil standards in a syringe or a vial . 18
6.3.1 Equipment . 19
6.3.2 Procedure . 20
7 Extraction of gases from oil . 20
7.1 General remarks. 20
7.2 Multi-cycle vacuum extraction using Toepler pump apparatus . 21
7.2.1 General . 21
7.2.2 Toepler pump extraction apparatus . 21
7.2.3 Extraction procedure . 24
7.3 Vacuum extraction by partial degassing method . 25
7.3.1 General remark . 25
7.3.2 Partial degassing apparatus . 25
7.3.3 Extraction procedure . 26
7.4 Stripping extraction method . 26
7.4.1 General . 26
7.4.2 Stripping apparatus . 26
7.4.3 Outline of procedure . 29
7.5 Headspace method . 30
7.5.1 Principle of the method . 30

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IEC CDV 60567 © IEC 2023 – 3 –
7.5.2 Symbols and abbreviations . 30
7.5.3 Headspace extraction apparatus. 31
7.5.4 Headspace extraction procedure . 35
7.5.5 Calibration of the headspace extractor . 39
8 Gas analysis by gas-solid chromatography . 41
8.1 General remarks. 41
8.2 Outline of suitable methods using Table 4 . 42
8.3 Apparatus . 42
8.3.1 Gas chromatograph . 42
8.3.2 Columns . 44
8.3.3 Carrier gas . 44
8.3.4 Detectors . 44
8.3.5 Methanator . 44
8.3.6 Cold trap . 44
8.3.7 Integrator and recorder . 44
8.4 Preparation of apparatus . 45
8.5 Analysis . 45
8.6 Calibration of the chromatograph . 45
8.7 Calculations . 46
9 Quality control . 46
9.1 Verification of the entire analytical system . 46
9.2 Limits of detection and quantification . 47
9.3 Repeatability, reproducibility and accuracy . 47
9.3.1 General remark . 47
9.3.2 Repeatability . 48
9.3.3 Reproducibility . 48
9.3.4 Accuracy . 48
10 Report of results . 49
Annex A (informative) Correction for incomplete gas extraction in partial degassing

method by calculation . 51
Annex B (informative) Mercury-free versions of the standard extraction methods . 53
Annex C (informative) Preparation of air-saturated standards . 56
Annex D (informative) Correction for gas bubbles in syringes and air gap in rigid
bottles . 57
Annex E (informative) Procedure for comparing gas monitor readings to laboratory
results . 58
PART 2 - INSULATING LIQUIDS BASED ON SYNTHETIC AND NATURAL ESTERS
59
AND SILICONES .
Bibliography . 61

Figure 1 – Sampling of gas by syringe . 11
Figure 2 – Sampling of free gases by oil displacement . 12
Figure 3 – Sampling of free gases by vacuum . 13
Figure 4 – First method of preparing gas-in-oil standards . 17
Figure 5 – Second method for preparing gas-in-oil standards . 19
Figure 6 – Example of a Toepler pump extraction apparatus . 23
Figure 7 – Types of glass strippers . 27

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Figure 8 – Stainless steel stripper . 28
Figure 9 – Schematic arrangement for connecting an oil stripper to a gas
chromatograph . 29
Figure 10 – Schematic representation of headspace sampler . 30
Figure 11 – Vial filled with water . 32
Figure 12 – Revolving table . 34
Figure 13 – Schematic arrangement for gas chromatography . 43
Figure B.1 – Schematic representation of methods in Annex B . 54

Table 1 – Information required for gas samples . 14
Table 2 – Examples of headspace operating conditions . 35
Table 3 – Headspace partition coefficients at 70 °C in mineral insulating oil . 40
Table 4 – Examples of gas chromatographic operating conditions . 41
Table 5 – Required limits of detection in oil . 47
Table 6 – Examples of accuracy of extraction methods . 49
Table A.1 – Examples of solubility coefficients a (at 25 ºC) reported by CIGRE TF
i
D1.01.15 in 2006 . 51
Table C.1 – Examples of solubility values of air for different oil types . 56
Table C.2 – Examples of temperature variations for oxygen and nitrogen solubility in
mineral oil . 56

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oSIST prEN IEC 60567:2023
IEC CDV 60567 © IEC 2023 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

OIL-FILLED ELECTRICAL EQUIPMENT –
SAMPLING OF FREE GASES AND ANALYSIS
OF FREE AND DISSOLVED GASES –
GUIDANCE

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,
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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-
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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
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60567 has been prepared by IEC technical committee 10: Fluids
for electrotechnical applications.
This edition cancels and replaces the previous edition, published in 2005, and constitutes a
technical revision.
The main changes with respect to the previous edition are listed below:
Since the publication of the third edition, CIGRE TF.D1.01.15 has made progress in several
areas of dissolved gas analysis (DGA), notably
a) oil sampling,
b) laboratory analysis and solubility coefficients of gases in non-mineral oils,
c) calibration of the headspace gas extraction method,

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d) more sensitive detectors for chromatography,
e) preparation of air-saturated standards and
f) evaluation of gas monitor readings.
These advances are included in this fourth edition.
Sampling of oil for DGA from oil-filled equipment has been moved from IEC 60567 to
IEC 60475 as reflected in the revised title of this standard.
The text of this standard is based on the following documents:
FDIS Report on voting
10/849/FDIS 10/872/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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oSIST prEN IEC 60567:2023
IEC CDV 60567 © IEC 2023 – 7 –
1 INTRODUCTION
2 Gases may be formed in oil-filled electrical equipment due to natural ageing but also, to a
3 much greater extent, as a result of faults.
4 Operation with a fault may seriously damage the equipment, and it is valuable to be able to
5 detect the fault at an early stage of development.
6 Where a fault is not severe, the gases formed will normally dissolve in the oil, with a small
7 proportion eventually diffusing from the liquid into any gas phase above it. Extracting
8 dissolved gas from a sample of the oil and determining the amount and composition of this
9 gas is a means of detecting such faults, and the type and severity of any fault may often be
10 inferred from the composition of the gas and the rate at which it is formed.
11 In the case of a sufficiently severe fault, free gas will pass through the oil and collect in the
12 gas-collecting (Buchholz) relay if fitted; if necessary, this gas may be analysed to assist in
13 determining the type of fault that has generated it. The composition of gases within the
14 bubbles changes as they move through the oil towards the gas-collecting relay.
15 This can be put to good use, as information on the rate of gas production may often be
16 inferred by comparing the composition of the free gases collected with the concentrations
17 remaining dissolved in the liquid.
18 The interpretation of the gas analyses is the subject of IEC 60599.
19 These techniques are valuable at all stages in the life of oil-filled equipment. During
20 acceptance tests on transformers in the factory, comparison of gas-in-oil analyses before,
21 during and after a heat run test can show if any hot-spots are present, and similarly analysis
22 after dielectric testing can add to information regarding the presence of partial discharges or
23 sparking. During operation in the field, the periodic removal of an oil sample and analysis of
24 the gas content serve to monitor the condition of transformers and other oil-filled equipment.
25 The importance of these techniques has led to the preparation of this standard, to the
26 procedures to be used for the sampling, from oil-filled electrical equipment, of gases and oils
27 containing gases, and for subsequent analysis.
28 NOTE Methods described in this standard apply to insulating oils, since experience to date has been almost
29 entirely with such oils. The methods may also be applied to other insulating liquids, in some cases with
30 modifications.
31 General caution, health, safety and environmental protection
32 This International Standard does not purport to address all the safety problems associated
33 with its use. It is the responsibility of the user of the standard to establish appropriate health
34 and safety practices and determine the applicability of regulatory limitations prior to use.
35 The insulating oils which are the subject of this standard should be handled with due regard to
36 personal hygiene. Direct contact with the eyes may cause irritation. In the case of eye
37 contact, irrigation with copious quantities of clean running water should be carried out and
38 medical advice sought. Some of the tests specified in this standard involve the use of
39 processes that could lead to a hazardous situation. Attention is drawn to the relevant standard
40 for guidance.
41 Mercury presents an environmental and health hazard. Any spillage should immediately be
42 removed and be properly disposed of. Consult local regulations for mercury use and handling.
43 Mercury-free methods may be requested in some countries.
44

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45 Environment
46 This standard is applicable to insulating oils, chemicals and used sample containers.
47 Attention is drawn to the fact that, at the time of writing of this standard, many insulating oils
48 in service are known to be contaminated to some degree by PCBs. If this is the case, safety
49 countermeasures should be taken to avoid risks to workers, the public and the environment
50 during the life of the equipment, by strictly controlling spills and emissions. Disposal or
51 decontamination of these oils should be carried out strictly according to local regulations.
52 Every precaution should be taken to prevent release of insulating oil into the environment.
53

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IEC CDV 60567 © IEC 2023 – 9 –
54 OIL-FILLED ELECTRICAL EQUIPMENT –
55 SAMPLING OF FREE GASES AND ANALYSIS
56 OF FREE AND DISSOLVED GASES –
57 GUIDANCE
58
59 PART 1 – Mineral oil
60
61 1 Scope
62 This International Standard deals with the techniques for sampling free gases from gas-
63 collecting relays from power transformers. Three methods of sampling free gases are
64 described.
65 The techniques for sampling oil from oil-filled equipment such as power and instrument
66 transformers, reactors, bushings, oil-filled cables and oil-filled tank-type capacitors are no
67 longer covered by this standard, but are instead described in 4.2 of IEC 60475:2011.
68 Before analysing the gases dissolved in oil, they are first extracted from the oil. Three basic
69 methods are described, one using extraction by vacuum (Toepler and partial degassing),
70 another by displacement of the dissolved gases by bubbling the carrier gas through the oil
71 sample (stripping) and the last one by partition of gases between the oil sample and a small
72 volume of the carrier gas (headspace). The gases are analysed quantitatively after extraction
73 by gas chromatography; a method of analysis is described. Free gases from gas-collecting
74 relays are analysed without preliminary treatment.
75 The preferred method for assuring the performance of the gas extraction and analysis
76 equipment, considered together as a single system, is to degas samples of oil prepared in the
77 laboratory and containing known concentrations of gases (“gas-in-oil standards”) and
78 quantitatively analyse the gases extracted. Two methods of preparing gas-in-oil standards are
79 described.
80 For daily calibration checks of the chromatograph, it is convenient to use a standard gas
81 mixture containing a suitable known amount of each of the gas components to be in a similar
82 ratio to the common ratios of the gases extracted from transformer oils.
83 The techniques described take account, on the one hand, of the problems peculiar to
84 analyses associated with acceptance testing in the factory, where gas contents of oil are
85 generally very low and, on the other hand, of the problems imposed by monitoring equipment
86 in the field, where transport of samples may be by un-pressurized air freight and where
87 considerable differences in ambient temperature may exist between the plant and the
88 examining laboratory.
89 2 Normative references
90 The following documents, in whole or in part, are normatively referenced in this document and
91 are indispensable for its application. For dated references, only the edition cited applies. For
92 undated references, the latest edition of the referenced document (including any
93 amendments) applies.
94 IEC 60296, Fluids for electrotechnical applications – Unused mineral insulating oils for
95 transformers and switchgear
96 IEC 60475:2011, Method of sampling insulating liquids

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97 IEC 60599, Mineral oil-impregnated electrical equipment in service – Guide to the inter-
98 pretation of dissolved and free gases analysis
99 ISO 5725 (all parts), Accuracy (trueness and precision) of measurement methods and results
100 ASTM D2780, Standard Test Method for Solubility of Fixed Gases in Liquids
101 3 Sampling of gases from gas-collecting (Buchholz) relays
102 3.1 General remarks
103 It is important to bear in mind that receiving a qualitative and a representative sample is
104 crucial for obtaining a reliable diagnosis of the electrical equipment. Even the most
105 sophisticated extraction or diagnosis methods cannot overcome faulty samples.
106 Gas samples from relays should be tak
...