ISO/IEC 80079-38:2016

ISO/IEC 80079-38
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 38: Equipment and components in explosive atmospheres in underground
mines

Atmosphères explosives –
Partie 38: Appareils et composants destinés à être utilisés dans les mines
souterraines grisouteuses

ISO/IEC 80079-38:2016-02(en-fr)

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ISO/IEC 80079-38


Edition 1.0 2016-02




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











Explosive atmospheres –

Part 38: Equipment and components in explosive atmospheres in underground

mines




Atmosphères explosives –

Partie 38: Appareils et composants destinés à être utilisés dans les mines


souterraines grisouteuses














INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 13.230; 29.260.20 ISBN 978-2-8322-3180-7



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.

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– 2 – ISO/IEC 80079-38:2016
  ISO/IEC 2016
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 9
2 Normative references. 9
3 Terms, definitions and abbreviated terms . 10
4 Requirements for equipment (machines) and components . 14
4.1 General . 14
4.2 Ignition hazard assessment . 15
4.2.1 Formal analysis . 15
4.2.2 Assessment for equipment-group I, EPL Mb . 15
4.2.3 Establishing the maximum surface temperature . 15
4.2.4 Dust deposits and other material in the gap of moving parts . 15
4.2.5 Ignition hazard assessment report . 16
4.2.6 Ignition sources . 16
4.3 Non-electrical equipment and components . 16
4.4 Electrical equipment and components . 16
4.4.1 General . 16
4.4.2 Electrical equipment protection . 17
4.4.3 Over-current protection . 17
4.4.4 Earth-fault protection . 18
4.4.5 Mechanical protection of live parts . 19
4.4.6 Electric cables that are part of the equipment . 19
5 Additional requirements for specific equipment and components . 20
5.1 Cutting and stripping equipment . 20
5.1.1 General . 20
5.1.2 Machines with cutting picks . 20
5.1.3 Stripping machines . 21
5.2 Rope haulages for level and inclined transport . 21
5.3 Fans . 21
5.3.1 Ventilating fans for use in underground parts of mine . 21
5.3.2 Other fans . 23
5.4 Internal combustion engines . 23
5.5 Air compressors . 24
5.6 Drilling equipment and components . 24
5.7 Brakes . 25
5.7.1 Brakes used only for stopping in emergency . 25
5.7.2 Service brakes (including friction brakes and fluid based retarders) . 25
5.7.3 Parking brakes . 25
5.8 Traction batteries, starter batteries and vehicle lighting batteries . 25
5.9 Optical fibres used on machines and electromagnetic radiation from
components on machines . 26
5.9.1 External pipes/optical fibres . 26
5.9.2 Radio-frequency radiation from equipment . 26
5.10 Gas monitoring systems . 26
6 Fire protection . 27
6.1 General . 27

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ISO/IEC 80079-38:2016 – 3 –
 ISO/IEC 2016
6.2 Non-metallic materials . 27
6.3 Hydraulic and pneumatic equipment . 27
6.4 Requirements for cable-reeled equipment . 29
6.4.1 General . 29
6.4.2 Special requirements . 29
6.5 Fire prevention on electric cables that are part of the machine . 29
6.6 Conveyor belting . 29
7 Information for use . 30
7.1 Signals and warning notices . 30
7.2 Instructions . 30
7.2.1 Information on use . 30
7.2.2 Information on maintenance and repair . 30
8 Marking . 30
Annex A (informative) Example of an ignition hazard assessment for a conveyor belt
intended for use in a coal mine. 32
A.1 General . 32
A.2 EPL and intended use of the equipment . 32
A.3 Construction and description of the equipment . 32
A.4 Assessment . 33
Annex B (informative) Example of an ignition hazard assessment for a shearer loader
intended for use in a potentially explosive atmosphere of a coal mine . 36
B.1 General . 36
B.2 EPL and intended use of equipment . 36
B.3 Construction/description of the equipment with regard to ignition protection . 36
B.4 Ignition control and monitoring system . 37
B.5 Compliance with the basic methodology and requirements in ISO 80079-36 . 37
B.6 Ignition hazard assessment of the electrical parts of the equipment . 38
B.7 Ignition hazard assessment of non-electrical ignition sources . 38
B.8 Equipment marking . 38
Annex C (normative) Ignition sources . 42
C.1 Hot surfaces . 42
C.2 Flames and hot gases (including hot particles) . 42
C.3 Mechanically generated sparks . 43
C.4 Electrical equipment . 43
C.5 Stray electric currents . 43
C.6 Static electricity. 44
C.7 Lightning . 44
4 12
C.8 Radio frequency (RF) electromagnetic waves from 10 Hz to 3 × 10 Hz
(high frequency) . 44
11 15
C.9 Electromagnetic waves from 3 × 10 Hz to 3 × 10 Hz . 45
C.10 Ionizing radiation . 45
C.11 Ultrasonics . 45
C.12 Adiabatic compression and shock waves . 45
C.13 Exothermic reactions, including self-ignition of dusts . 46
Annex D (informative) Guidance on potential risks for converter-fed motors . 47
Annex E (normative) Tests for surface protective coating for group I hand tools
of EPL Mb . 48
E.1 Incendive impact tests in explosive mixture . 48
E.1.1 Verification of ignition of the raw light alloy material . 48

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– 4 – ISO/IEC 80079-38:2016
  ISO/IEC 2016
E.1.2 Estimation of protective coating efficiency . 48
E.1.3 Evaluation of results . 49
E.2 Adhesion test of the protective coating . 49
Bibliography . 51

Figure B.1 – Layout and construction of the coal face shearer loader . 37
Figure E.1 – Rig for impact ignition test . 50

Table 1 – Combination of materials . 23
Table 2 – Limit values for hydraulic fluids . 28
Table A.1 – Example of an ignition hazard assessment for a mining conveyor, EPL Mb
(1 of 2) . 33
Table B.1 – Example of an ignition hazard assessment for a shearer loader, EPL Mb
(1 of 3) . 39

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ISO/IEC 80079-38:2016 – 5 –
 ISO/IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

EXPLOSIVE ATMOSPHERES –

Part 38: Equipment and components in explosive
atmospheres in underground mines

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
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard ISO/IEC 80079-38 has been prepared by subcommittee 31M: Non-
electrical equipment and protective systems for explosive atmospheres, of IEC technical
committee 31: Equipment for explosive atmospheres.
It is published as a double logo standard.
The text of this standard is based on the following documents of the IEC:
FDIS Report on voting
31M/105/FDIS 31M/111/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. In ISO, the standard has been approved by 13 P members
out of 21 having cast a vote.

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– 6 – ISO/IEC 80079-38:2016
  ISO/IEC 2016
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
"A list of all parts in the IEC 60079 series, under the general title Explosive atmospheres, as
well as the International Standard 80079 series, can be found on the IEC website."
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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ISO/IEC 80079-38:2016 – 7 –
 ISO/IEC 2016
INTRODUCTION
This part of ISO/IEC 80079 specifies requirements for the constructional features of
equipment and components that may be an individual item or form an assembly, to enable
them to be used in mines, or parts of mines, susceptible to explosive atmospheres of firedamp
and/or combustible dust.
Most of the electrical equipment used on mining machinery is certified as an individual item of
equipment, e.g. the motor, switchgear etc., and meets its own marking requirements. This
certification, however, does not deal with the interconnection of these items of equipment by
cables or the machine electrical power system as an entity. The equipment and components,
including their interconnections, should be assessed, from an ignition point of view, by the
manufacturer.
Both non-electrical equipment and the interconnection of electrical/non-electrical equipment
require an ignition hazard assessment.
Therefore, it is necessary that not just the equipment, but all its parts, is examined by the
manufacturer according to a formally documented ignition hazard assessment that establishes
and lists all the possible ignition sources of the equipment including the cables and electrical
supply system. The documentation shall list the measures that shall be introduced to keep
possible ignition sources from becoming effective.
The need for this International Standard arises because of major operational differences
between underground mining operations and those in other industries working with, or in,
explosive atmospheres. Examples of these differences are:
– the product being won from the underground strata may be combustible and may
continually release firedamp during the winning process;
– the ignitability of the atmosphere around equipment and components usually depends
upon the amount of dilution offered by an active ventilating system;
– the atmosphere in the general body of mine air in which machinery is working may change
from one that is potentially explosive to one that is explosive (for example, during an
outburst of firedamp);
– persons working in the mine are usually situated within the potentially explosive
atmosphere;
– there is a need to monitor constantly the mine atmosphere at strategic places to ensure
that power can be disconnected from all equipment except Ma equipment which is suitable
for use in a constantly explosive atmosphere;
– in gassy coal mines, an explosion of firedamp at a machine can raise a combustible dust
cloud that exacerbates the explosion;
– some mining machinery, especially that associated with winning the product, contains
cutting devices and drilling devices that are intended to cut into the combustible product
as part of their normal operation. This introduces an ignition risk from frictional heating or
frictional sparking from contact with strata containing high concentrations of quartz or iron
pyrites;
– long roadways in coal mines are equipped with mineral conveying systems carrying a
product that has a potential for raising a combustible dust cloud and the production of
firedamp.
To decide which equipment or its component parts should merit inclusion in this International
Standard, ignition data has been examined based on international experience.
When drafting this International standard, it has been assumed that equipment and
components are:

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– 8 – ISO/IEC 80079-38:2016
  ISO/IEC 2016
– designed in accordance with good engineering practice, taking account of expected
shocks, vibrations and failure modes;
– of sound mechanical and electrical construction;
– made of materials with adequate strength and of suitable quality;
– free from defects; and
– kept in good repair and working order, e.g. so that the required dimensions remain within
permissible tolerance despite wear.

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ISO/IEC 80079-38:2016 – 9 –
 ISO/IEC 2016
EXPLOSIVE ATMOSPHERES –

Part 38: Equipment and components in explosive
atmospheres in underground mines



1 Scope
This part of ISO/IEC 80079 specifies the explosion protection requirements for the design,
construction, assessment and information for use (maintenance, repair, marking) of
equipment that may be an individual item or form an assembly.
This includes machinery and components for use in mines susceptible to explosive
atmospheres of firedamp and/or combustible dust. The standard atmospheric conditions
(relating to the explosion characteristics of the atmosphere) under which it may be assumed
that equipment can be operated are:
• temperature -20 °C to +60 °C;
• pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar); and
• air with normal oxygen content, typically 21 % v/v.
This part of ISO/IEC 80079 applies for equipment and components according to EPL Mb to be
used in explosive atmospheres containing firedamp and/or combustible dust.
NOTE 1 In some countries, there might be differences according to the classification, e.g. Mb is similar to
category M2 in the European Union.
For equipment and components according to EPL Ma, the requirements of this standard and
of ISO 80079-36 and IEC 60079-0 apply.
NOTE 2 A standard with additional requirements for EPL Ma is under preparation.
It is necessary to take account of external conditions to the equipment which may affect the
hazard and the resultant protection measures. These measures may include ventilation, gas
detection or gas drainage.
This part of ISO/IEC 80079 also deals with the prevention of ignitions of explosive
atmospheres caused by burning (or smouldering) of combustible material such as fabric
fibres, plastic ”O”-rings, rubber seals, lubricating oils or greases used in the construction of
the equipment if such items could be an ignition source. For example, the m
...