IEC 61112:2009

Live working - Electrical insulating blankets

IEC 61112:2009 is applicable to electrical insulating blankets for the protection of workers from accidental contact with live or earthed electrical conductors, apparatus or circuits and avoidance of short circuits on electrical installations. This second edition cancels and replaces the first edition, published in 1992, and its Amendment 1 (2002). This edition constitutes a technical revision. It includes the following significant technical changes from the previous edition:
- general review of the requirements and test provisions;
- limitation of the scope in terms of the minimum width of electrical insulating blankets in rolls;
- preparation of the elements of evaluation of defects, and general application of IEC 61318 Ed.3;
- revision of existing annexes;
- deletion of Annexes D and F, not applicable according to IEC 61318 Ed.3;
- introduction of a new normative Annex F on classification of defects.

Travaux sous tension - Nappes isolantes électriques

La CEI 61112:2009 est applicable aux nappes isolantes électriques pour la protection des travailleurs contre un contact accidentel avec des conducteurs électriques sous tension ou mis à la terre, des appareils ou des circuits, et contre les courts-circuits dans des installations électriques. Cette édition annule et remplace la première édition publiée en 1992 ainsi que son Amendement 1 (2002), et constitue une révision technique. Elle inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- la révision générale des exigences et des dispositions d'essai;
- la limitation de l'étendue du domaine d'application en ce qui a trait à la largeur minimale des nappes isolantes électriques en rouleaux;
- la préparation des éléments d'évaluation des défauts et de l'application générale de la CEI 61318 Ed.3;
- la révision des annexes existantes;
- la disparition des Annexe D et F qui ne sont plus applicables, en accord avec la CEI 61318 Ed.3;
- l'introduction d'une nouvelle Annexe F normative traitant de la classification des défauts.

General Information

• Status: Published
• Publication Date: 06-Apr-2009
• ICS: 13.260 - Protection against electric shock. Live working
• ICS: 29.240.20 - Power transmission and distribution lines
• ICS: 29.260.99 - Other electrical equipment for working in special conditions
• Technical Committee: TC 78 - Live working
• Current Stage: PPUB - Publication issued
• Start Date: 07-Apr-2009
• Completion Date: 07-Apr-2009

Standards Content (sample)

IEC 61112
Edition 2.0 2009-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Live working – Electrical insulating blankets
Travaux sous tension – Nappes isolantes électriques
IEC 61112:2009
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---------------------- Page: 2 ----------------------
IEC 61112
Edition 2.0 2009-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Live working – Electrical insulating blankets
Travaux sous tension – Nappes isolantes électriques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX
ICS 13.260; 29.240.20; 29.260.99 ISBN 978-2-88910-414-7
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
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– 2 – 61112 © IEC:2009
CONTENTS

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

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

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

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

3 Terms and definitions .......................................................................................................8

4 Requirements ...................................................................................................................9

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

4.2 Classification...........................................................................................................9

4.3 Physical requirements .............................................................................................9

4.3.1 Composition ................................................................................................9

4.3.2 Shape and design........................................................................................9

4.3.3 Dimensions and tolerances........................................................................11

4.3.4 Workmanship and finish ............................................................................11

4.4 Mechanical, climatic and environmental requirements ...........................................12

4.5 Dielectric requirements..........................................................................................12

4.6 Marking .................................................................................................................12

4.7 Packaging .............................................................................................................13

4.8 Instructions for use................................................................................................13

5 Tests ..............................................................................................................................13

5.1 General .................................................................................................................13

5.2 Visual inspection and measurements.....................................................................14

5.2.1 General .....................................................................................................14

5.2.2 Classification.............................................................................................14

5.2.3 Composition ..............................................................................................14

5.2.4 Dimensions, workmanship and finish .........................................................14

5.2.5 Thickness ..................................................................................................14

5.3 Marking .................................................................................................................15

5.3.1 Visual inspection and measurement ..........................................................15

5.3.2 Durability of marking..................................................................................15

5.4 Packaging and instructions for use ........................................................................15

5.5 Mechanical tests ...................................................................................................15

5.5.1 General .....................................................................................................15

5.5.2 Tensile strength and elongation at break ...................................................15

5.5.3 Mechanical puncture resistance.................................................................16

5.5.4 Tension set for elastomer material.............................................................18

5.5.5 Tear resistance test for plastic material .....................................................18

5.6 Dielectric tests ......................................................................................................19

5.6.1 General .....................................................................................................19

5.6.2 Electrodes .................................................................................................20

5.6.3 Test equipment..........................................................................................22

5.6.4 Electrical test procedure ............................................................................23

5.7 Ageing tests ..........................................................................................................24

5.8 Thermal tests ........................................................................................................25

5.8.1 Flame retardance test................................................................................25

5.8.2 Low temperature folding test (except for category C blankets) ...................26

6 Tests on electrical insulating blankets with special properties.........................................27

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61112 © IEC:2009 – 3 –

6.1 General .................................................................................................................27

6.2 Category A: Acid resistance ..................................................................................27

6.3 Category H: Oil resistance.....................................................................................27

6.4 Category Z: Ozone resistance ...............................................................................27

6.4.1 General .....................................................................................................27

6.4.2 Test methods.............................................................................................28

6.5 Category M: Mechanical puncture resistance.........................................................29

6.6 Category C: Extremely low temperature folding test ..............................................29

7 Conformity assessment of electrical insulating blankets having completed the

production phase............................................................................................................29

8 Modifications ..................................................................................................................30

Annex A (informative) Guidelines for the selection of the class of electrical insulating

blankets in relation to nominal voltage of a system ...............................................................31

Annex B (informative) In-service care and testing ................................................................32

Annex C (normative) Suitable for live working ; double triangle (IEC 60417-5216

(2002-10)).............................................................................................................................34

Annex D (normative) General type test procedure................................................................35

Annex E (normative) Liquid for tests on electrical insulating blankets of category H –

Oil resistance........................................................................................................................38

Annex F (normative) Classification of defects and tests to be allocated ...............................39

Bibliography..........................................................................................................................40

Figure 1 – Example of plain design .......................................................................................10

Figure 2 – Example of slotted design ....................................................................................10

Figure 3 – Plan view of the dumb-bell test piece ...................................................................16

Figure 4 – Test plates and needle for resistance to mechanical puncture..............................17

Figure 5 – Tear resistance test .............................................................................................19

Figure 6 – Test set-up for voltage proof test of electrical insulating blankets with

standard type of electrodes...................................................................................................20

Figure 7 – Test set-up for voltage proof test of electrical insulating blankets with

alternative type of electrodes ................................................................................................22

Figure 8 – Test set-up for voltage withstand test...................................................................23

Figure 9 – Test set-up for low and extremely low temperature folding tests...........................26

Figure 10 – Ozone resistance – Method B test set-up ...........................................................28

Table 1 – Special properties ...................................................................................................9

Table 2 – Common lengths and widths for electrical insulating blankets................................11

Table 3 – Maximum thickness for electrical insulating blankets .............................................11

Table 4 – Maximum electrode clearance for proof tests ........................................................21

Table 5 – Test voltages.........................................................................................................24

Table A.1 – Designation maximum use voltage .....................................................................31

Table D.1 – List and chronological order of type tests...........................................................35

Table E.1 – Characteristics of oil no. 1..................................................................................38

Table F.1 – Classification of defects and associated requirements and tests ........................39

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– 4 – 61112 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LIVE WORKING –
ELECTRICAL INSULATING BLANKETS
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

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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

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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with an IEC Publication.

6) All users should ensure that they have the latest edition of this publication.

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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 61112 has been prepared by IEC technical committee 78: Live

working.

This second edition cancels and replaces the first edition, published in 1992, and its

Amendment 1 (2002). This edition constitutes a technical revision.

It includes the following significant technical changes from the previous edition:

– general review of the requirements and test provisions;

– limitation of the scope in terms of the minimum width of electrical insulating blankets in

rolls;

– introduction of a definition of electrical insulating blankets including sheeting in various

shapes and in rolls;
– introduction of Class 00;
– withdrawal of category S and introduction of category R;

– clarification of the way electrical insulating blankets in rolls are covered by the test

procedures;
---------------------- Page: 6 ----------------------
61112 © IEC:2009 – 5 –

– specification of standard and alternative types of electrodes for the proof test;

– modification of the test procedures for low and extremely low temperature by replacing the

dielectric proof test by a withstand test in the sanction;

– modification of the test procedures for acid and oil resistance by specifying the use of test

pieces and by replacing the dielectric proof test by a withstand test in the sanction;

– specification of liquid 102 for the oil resistance test and harmonisation of the mechanical

test sanction with the acid resistance test;

– preparation of the elements of evaluation of defects, and general application of IEC 61318

Ed.3;
– revision of existing annexes;
– deletion of Annexes D and F, not applicable according to IEC 61318 Ed.3;
– introduction of a new normative Annex F on classification of defects.
The text of this standard is based on the following documents:
FDIS Report on voting
78/785/FDIS 78/799/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 maintenance result 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.
---------------------- Page: 7 ----------------------
– 6 – 61112 © IEC:2009
INTRODUCTION

This International Standard has been prepared according to the requirements of IEC 61477

where applicable.

The product covered by this standard may have an impact on the environment during some or

all stages of its life cycle. These impacts can range from slight to significant, be of short-term

or long-term, and occur at the global, regional or local level.

Except for a disposal statement in the instructions for use, this standard does not include

requirements and test provisions for the manufacturers of the product, or recommendations to

the users of the product for environmental improvement. However, all parties intervening in its

design, manufacture, packaging, distribution, use, maintenance, repair, reuse, recovery and

disposal are invited to take account of environmental considerations.
---------------------- Page: 8 ----------------------
61112 © IEC:2009 – 7 –
LIVE WORKING –
ELECTRICAL INSULATING BLANKETS
1 Scope

This International Standard is applicable to electrical insulating blankets for the protection of

workers from accidental contact with live or earthed electrical conductors, apparatus or

circuits and avoidance of short circuits on electrical installations.

Electrical insulating blankets in rolls having a width lower than 50 mm are not covered by this

standard.
NOTE 1 For a.c. electrical classification, as well as d.c. use, see 4.2.

NOTE 2 This standard gives a.c. test provisions. There is limited history for use in d.c. applications.

NOTE 3 See Annex A for suggested maximum voltage use.
2 Normative references

The following referenced documents are indispensable for the application 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 60060-1, High-voltage test techniques – Part 1: General definitions and test
requirements
IEC 60060-2, High-voltage test techniques – Part 2: Measuring systems
IEC 60068-1, Environmental testing – Part 1: General and guidance

IEC 60212:1971, Standard conditions for use prior to and during the testing of solid electrical

insulating materials
IEC 60417, Graphical symbols for use on equipment
IEC 61318, Live working – Conformity assessment applicable to tools, devices and
equipment

IEC 61477, Live working – Minimum requirements for the utilization of tools, devices and

equipment
ISO 2592, Determination of flash and fire points – Cleveland open cup method

ISO 2977, Petroleum products and hydrocarbon solvents – Determination of aniline point and

mixed aniline point

ISO 3104, Petroleum products – Transparent and opaque liquids – Determination of kinematic

viscosity and calculation of dynamic viscosity

ASTM D 3767:2003 (reapproved 2008): Standard practice for rubber – Measurement of

dimensions
---------------------- Page: 9 ----------------------
– 8 – 61112 © IEC:2009
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 61318 and the

following apply.
3.1
disruptive discharge
passage of an arc following dielectric breakdown

NOTE 1 The term “sparkover” (in French “amorçage”) is used when a disruptive discharge occurs in a gaseous or

liquid dielectric.

NOTE 2 The term “flashover” (in French “contournement”) is used when a disruptive discharge occurs at least

partly along the surface of a solid dielectric surrounded by a gaseous or liquid medium.

NOTE 3 The term “puncture” (in French “perforation”) is used when a disruptive discharge occurs through a solid

dielectric producing permanent damage.
[IEV 651-01-18 and definition 2.7.7 of IEC 60743, modified]
3.2
elastomer

macromolecular material which returns rapidly to its initial dimensions and shape after

substantial deformation by a weak stress and release of the stress
NOTE 1 The definition applies under room temperature test conditions.

NOTE 2 Elastomer is a generic term that includes rubber, latex and elastomeric compounds that may be natural

or synthetic or a mixture or a combination of both. It also includes thermoplastic elastomer (TPE) material.

[ISO 472 modified]
3.3
electrical insulating blanket

flexible sheeting made of elastomer or plastic material, used to cover conductors or metallic

parts which are either energized, dead or earthed

NOTE The sheeting is either of various definite shapes or in roll allowing the workers to custom-cut the material

to fit the application.
[Definition 5.2.2 of IEC 60743 and IEV 651-04-06, modified]
3.4
nominal voltage (of a system)
suitable approximate value of voltage used to designate or identify a system
[IEV 601-01-21]
3.5
plastic

material which contains as an essential ingredient a high polymer and which at some stage in

its processing into finished products can be shaped by flow

NOTE 1 Elastomeric materials, which also are shaped by flow, are not considered as plastics.

NOTE 2 In some countries, particularly in the United Kingdom, it is a permitted option to use the term “plastics” as

the singular form as well as the plural form.
[Definition 2.4.4 of IEC 60743 and ISO 472]
3.6
proof test voltage

specified voltage that is applied to a device or test piece for the time defined under specified

conditions to assure that the electrical strength of the insulation is above a specified value

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61112 © IEC:2009 – 9 –
3.7
withstand test voltage

voltage that a test piece is required to withstand without disruptive discharge or other electric

failure when voltage is applied under specified conditions
4 Requirements
4.1 General

Electrical insulating blanket shall be designed and manufactured to contribute to the safety of

the users provided they are used by skilled persons, in accordance with safe methods of work

and the instructions for use.
4.2 Classification

The electrical insulating blankets covered by this standard shall be designated as follows:

− by electrical class, as class 00, class 0, class 1, class 2, class 3 and class 4;

− by adding suffix(s) to the class designation, in the case of a blanket with special

category(s) as shown in Table 1.
Guidance for the selection of class (a.c. and d.c.) is given in Annex A.

Guidance as to the temperature range at which electrical insulating blankets can be used is

given in Annex B.
Table 1 – Special properties
Category Resistant to
A Acid
H Oil
Z Ozone
M Mechanical puncture
R Acid, Oil and Ozone
C Extremely low temperature
NOTE Any combination of categories may be used.
4.3 Physical requirements
4.3.1 Composition

Electrical insulating blankets shall be manufactured of elastomer or plastic materials and

produced by a seamless process. Where eyelets are provided in electrical insulating blankets

they shall be non-conductive. Where other types of fastening systems are provided in

electrical insulating blankets (for example hook and loop fastening) they shall also be non-

conductive.

NOTE A standard number, size and type of eyelets is usually proposed by the manufacturers. Eyelets of ∅8 mm

are the most common. For special needs, agreement could be reached between manufacturer and customer.

4.3.2 Shape and design

There is no requirement for the shape and design of the electrical insulating blankets.

Electrical insulating blankets may be either of various shapes or in rolls to be cut for individual

applications.
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– 10 – 61112 © IEC:2009

The electrical insulating blankets of various shapes may be plain or of the slotted design

(Figure 1 and Figure 2 provide examples of such design). They may include a grid of synthetic

fiber for their reinforcement. In all cases electrical insulating blankets may have a strap(s)

®1)
(Velcro ) around their perimeter.
IEC 456/09
Key
L Length
W Width
Figure 1 – Example of plain design
W W
IEC 457/09
Key
L Length
W Width
Figure 2 – Example of slotted design
———————

Velcro® is the trade name of a product supplied by Velcro Industries B.V. This information is given for the

convenience of users of this document and does not constitute an endorsement by IEC of the product named.

Equivalent products may be used if they can be shown to lead to the same results.

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