SIST EN 50628:2016

SLOVENSKI STANDARD
01-oktober-2016
1DPHVWLWHYHOHNWULþQLKLQãWDODFLMYSRG]HPQLKUXGQLNLK
Erection of electrical installations in underground mines
Errichten elektrischer Anlagen im Bergbau unter Tage
Construction des installations électriques dans les mines souterraines
Ta slovenski standard je istoveten z: EN 50628:2016
ICS:
29.260.20 (OHNWULþQLDSDUDWL]D Electrical apparatus for
HNVSOR]LYQDR]UDþMD explosive atmospheres
73.100.01 Rudarska oprema na splošno Mining equipment in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 50628
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2016
ICS 29.260.20
English Version
Erection of electrical installations in underground mines
Construction des installations électriques dans les mines Errichten elektrischer Anlagen im Bergbau unter Tage
souterraines
This European Standard was approved by CENELEC on 2016-05-23. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50628:2016 E
Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 9
4 General . 21
4.1 General requirements . 21
4.2 Initial inspections. 22
4.3 Competence of personnel . 22
4.4 Documentation . 22
5 Means of protection against electric- and electrostatic charging . 23
6 Rooms and Locations . 23
6.1 Electrical service rooms . 23
6.2 Closed electrical service rooms . 23
6.3 Other rooms . 23
7 Protection against fire spreading . 24
7.1 General requirements . 24
8 Insulation, Insulation-resistance and its check . 24
8.1 Insulation . 24
8.2 Value of insulation resistance . 25
8.3 Insulation resistance check . 25
9 Signboards, labels, wiring diagrams, inscriptions . 26
9.1 General requirements . 26
10 Nominal voltages . 26
10.1 General requirements . 26
10.2 Voltage ranges . 27
11 Protection against electrical shock . 27
11.1 Requirements for basic protection . 27
11.1.1 Protection by basic insulation of live parts . 27
11.1.2 Protection by barriers or enclosures . 27
11.1.3 Protection by obstacles and placing out of reach . 28
11.2 Requirements for fault protection . 28
12 Protection in IT-Systems . 28
12.1 General . 28
12.2 Earth fault detection in IT-systems . 29
12.3 Design of IT system . 29
12.4 Insulation monitoring . 30
12.5 Protective conductor . 31
12.6 Electrical protection devices in IT-systems . 33
12.7 Design of cables being monitored by a protection device . 36
13 Protection in TN-systems . 37
13.1 TN-S- systems with residual current devices (RCD) . 37
13.2 TN-S System without residual current devices (RCD) . 38
14 Other means of protection . 38
15 Protection against danger caused by mechanical influence on non-intrinsically safe

cables. 38
15.1 General requirements . 38
15.2 Cables to supply mobile electrical equipment . 39
15.3 Cable in areas of mining activities or road heading areas till 50 m far from the road

heading face . 40
16 Intrinsically safe electrical systems . 40
16.1 General requirements for selection . 40
16.2 Descriptive system document . 40
16.3 Erection . 40
16.4 Separation of intrinsically and non-intrinsically safe circuits . 41
16.5 Separation of different intrinsically safe circuits . 42
16.6 Earthing . 42
16.7 Cable for intrinsically safe systems . 42
17 Installation of transformers . 42
18 Substations . 42
19 Disconnecting devices in line of each switch-gears . 43
20 Switchgears . 43
21 Couplers and connectors . 43
21.1 General requirements for use of couplers and connectors . 43
21.2 Additional requirements using couplers . 43
22 Luminaries and lighting installation . 44
23 Cables . 44
23.1 Design of cables . 44
23.2 Conductor materials . 45
23.3 Current carrying capacity . 45
23.4 Coverings and outer protective covers. 45
23.5 Different circuits within one cable . 46
23.6 Laying out of cables . 46
23.7 Glanding, terminating or making off . 47
23.8 Laying out of non-insulated conductors . 48
23.9 Additional requirements for the use of single core cable . 49
24 Protection of electrical equipment or installation against overcurrent . 49
24.1 Overcurrent protection devices . 49
24.2 Overload protection . 50
24.3 Short circuit protection . 50
24.4 Minimum short circuit current . 51
25 Calculation of short circuit currents . 52
26 Additional requirements for systems and equipment with nominal voltage of more than

1 kV up to 6,6 kV in production areas and road heading . 52
26.1 General requirements . 52
26.2 Switchgears . 52
26.3 Test of insulation resistance of non-alive cable in production areas and road headings . 52
26.4 Insulation monitoring of alive systems . 53
26.5 Earth protection in IT systems . 53
26.6 Monitoring of non-alive systems . 53
26.7 Electrical protection devices for feeding cables of electrical equipment . 54
26.8 Cable design . 54
27 Additional requirements for cable entry selection . 54
Annex A (informative) Documentation . 55
Annex B (normative) Tables and figures regarding free space . 56
Annex C (informative) Example for a galvanically separated system (in production areas or road

headings) . 58
Annex D (informative) Example for calculation (according to 12.3.6) . 61
D.1 General . 61
D.2 Legend . 61
D.3 Necessary system parameters . 61
D.4 Determination of the reference points of the system . 61
D.5 Calculation of the capacitive earth fault current and displaying in a figure (see Figure D.2) . 62
D.6 Overlay of capacitive and inductive earth fault current I – I = I . 62
eL eC eB.
D.7 Calculation of the voltage drop caused by the wattles component of the earth fault

current . 63
D.8 Calculation of the voltage drop caused by the active component of the earth fault current . 64
D.9 Resulting voltage drop U by geometrical addition . 64
F
Annex E (informative) Table for cables suitable for underground workings . 66
Annex F (informative) Table for current carrying capacity of cables suitable for underground

workings . 73
Bibliography . 76

European foreword
This document (EN 50628:2016) has been prepared by CLC/TC 31 “Electrical apparatus for potentially
explosive atmospheres”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2017-05-23
implemented at national level by publication
of an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2020-05-23
conflicting with this document have to
be withdrawn
This document will be read in conjunction with the European Standards for the specific types of protection
listed in the EN 60079 series of standards.
This document will also be read in conjunction with EN 1127-2.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights.
Introduction
When electrical equipment is to be installed in underground workings where an explosive atmosphere is likely
to occur, protective measures are applied to avoid the ignition of firedamp either under normal operation of the
electrical installation or under fault conditions.
Mines can be either gassy or non-gassy depending upon the mineral/material being extracted and whether or
not firedamp can occur in the workings. It is usual practice to consider all coal mines as gassy mines. Non-
coal mines can however, also be susceptible to the occurrence of firedamp e.g. if they are mining
minerals/materials in the vicinity of oil bearing strata or unworked coal seams which are to be disturbed by the
mining process, or are susceptible to outbursts of flammable gas.
Due to the fact that in underground workings firedamp is one of the major mining hazards that is to be
considered all pieces of electrical equipment need to be selected with regard to this hazard. If there are other
significant explosive atmospheres than firedamp the hazard occurring from these explosive atmospheres
needs to be taken into account.
Directive 2014/34/EU extends the definition of potentially explosive atmosphere to include combustible dust as
1)
well as firedamp. Extensive research has shown that the minimum ignition energy (MIE) of coal dust/ air
mixture is several hundred times higher than that of a firedamp/ air mixture and that the maximum
experimental safe gap (MESG) for coal dust particles is more than double that for firedamp. It is therefore
reasonable to assume that equipment, protective systems and components that are designed, constructed
and maintained for use in firedamp/ air mixtures are also suitable for use in coal dust/ air mixtures.
Unlike Group II it will be assumed that in Group I industry nearly all underground workings need to be
assessed where an explosive atmosphere is likely to occur and classified accordingly as hazardous areas. A
zone classification for such underground workings is not possible because the degree of exposure of such an
underground working does not depend on local parameters but on time parameters. In accordance with
2014/34/EU (ATEX-Directive) the exposure of the installed equipment may change from normally acceptable
firedamp concentration in the mine air (hazardous condition 2; M2 equipment sufficient) to elevated methane
concentration (hazardous condition 1; M1 equipment required, M2 equipment to be de-energized) and vice
versa.
Areas of a coal mine could be non-hazardous according to national regulations. In such areas equipment that
is not ATEX approved may be used, too subject to the risk assessment and specific local rules where national
regulations require.
In non-gassy mines it can be possible that in certain regions in the underground workings explosive
atmospheres can occur. In these cases national regulations will apply.
In mines where the atmosphere, in addition to firedamp, may contain significant proportions of other
flammable gases than firedamp, the installed Group I equipment complies also with the subdivision of Group II
corresponding to the other significant flammable gases.
In any underground working, irrespective of the size, there may be numerous sources of ignition apart from
those associated with electrical equipment. Precautions will be necessary to ensure safety from other possible
ignition sources, but guidance on this aspect is outside the scope of this standard.
Underground mining activities cause other special problems to the electrical installation as well as those
arising from firedamp. Rough environmental conditions evoked by climate – temperature and humidity e.g. –
rock pressure caused by depth, geometric dimensions of the underground workings, the winning process itself
and other similar circumstances require therefore special specifications to the electrical installation in
underground mines.
1) Survey on the use of flameproof enclosures in coal dust and methane atmospheres, G. A. Lunn,
SM/97/01.
1 Scope
This European Standard specifies the safety requirements for the erection of new electrical installations.
This European Standard is supplementary to other relevant harmonized standards, for example HD 60364
series and the EN 61936 series as regards electrical installation requirements.
This European Standard also refers to EN 60079-0 and its associated standards for the construction, testing
and marking requirements of suitable electrical equipment.
EN 60079-14 gives the specific requirements for design, selection and erection of electrical installations in
explosive atmospheres.
NOTE EN 60079–14 can apply to electrical installations in mines where explosive gas atmospheres other than
firedamp can be formed and to electrical installations in the surface installation of mines.
This European Standard applies to:
a) electrical installation in underground workings of mines;
b) electrical installations and parts of electrical installation above ground, which are directly connected with
the underground workings in functional and safety relating matters because of being part of the
underground working process:
These are in particular:
• safety and monitoring devices relating to the power distribution of the underground workings,
• communication system of hoisting and inclined haulage plants,
• intrinsically safe electrical installations of above ground installation being part of underground
workings,
• remote control systems if they shall fulfil increased requirements relating to functional safety,
• electrical installation and electrical equipment of ventilation systems and shaft casings above ground
being endangered by firedamp of the underground ventilation,
• firedamp drainage systems;
c) electrical installation in underground workings outside mining if it is demanded of the competent national
authorities.
National regulations of the mining authority shall remain unaffected.
This standard applies to installations at all voltages mentioned in Clause 10.
Requirements above both columns are requirements for all underground workings.
Gassy mines Other mines
Requirements within left column are Requirements within right column are
requirements for underground workings in the requirements for underground workings of the
coal mining industry which could be endangered coal mining industry not likely to be endangered
by firedamp. by firedamp and for underground workings of
non-coal mining industry.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
HD 631.1 S2, Electric cables — Accessories — Material characterisation — Part 1: Fingerprinting and type
tests for resinous compounds
EN 50303, Group I, Category M1 equipment intended to remain functional in atmospheres endangered by
firedamp and/or coal dust
EN 50393, Test methods and requirements for accessories for use on distribution cables of rated voltage
0,6/1,0 (1,2) kV
EN 60038, CENELEC standard voltages (IEC 60038)
EN 60079-0, Explosive atmospheres - Part 0: Equipment - General requirements (IEC 60079-0)
EN 60079-1, Explosive atmospheres — Part 1: Equipment protection by flameproof enclosures "d"
(IEC 60079-1)
EN 60079-7:2007, Explosive atmospheres - Part 7: Equipment protection by increased safety "e" (IEC 60079-
7:2006)
EN 60079-10-1, Explosive atmospheres — Part 10-1: Classification of areas — Explosive gas atmospheres
(IEC 60079-10-1)
EN 60079-10-2, Explosive atmospheres — Part 10-2: Classification of areas — Explosive dust atmospheres
(IEC 60079-10-2)
EN 60079-11:2012, Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i" (IEC 60079-
11:2011)
EN 60079-14, Explosive atmospheres — Part 14: Electrical installations design, selection and erection
(IEC 60079-14)
EN 60079-25, Explosive atmospheres - Part 25: Intrinsically safe electrical systems (IEC 60079-25)
EN 60204-1, Safety of machinery - Electrical equipment of machines - Part 1: General requirements
(IEC 60204-1)
EN 60296, Fluids for electrotechnical applications - Unused mineral insulating oils for transformers and
switchgear (IEC 60296)
EN 60309-1, Plugs, socket-outlets and couplers for industrial purposes - Part 1: General requirements (IEC
60309-1)
EN 60332-1-2, Tests on electric and optical fibre cables under fire conditions - Part 1-2: Test for vertical flame
propagation for a single insulated wire or cable - Procedure for 1 kW pre-mixed flame (IEC 60332-1-2)
HD 60364-4-41:2007, Low-voltage electrical installations - Part 4-41: Protection for safety - Protection against
electric shock (IEC 60364-4-41:2005)
EN 60529, Degrees of protection provided by enclosures (IP Code) (IEC 60529)
EN 60664-1, Insulation coordination for equipment within low-voltage systems - Part 1: Principles,
requirements and tests (IEC 60664-1)
EN 60836, Specifications for unused silicone insulating liquids for electrotechnical purposes (IEC 60836)
EN 60865-1, Short-circuit currents - Calculation of effects - Part 1: Definitions and calculation methods
(IEC 60865-1)
EN 60909 (all parts), Short-circuit currents in three-phase a.c systems (IEC 60909 series)
EN 61099, Insulating liquids - Specifications for unused synthetic organic esters for electrical purposes
(IEC 61099)
EN 61557-6, Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. -
Equipment for testing, measuring or monitoring of protective measures - Part 6: Effectiveness of residual
current devices (RCD) in TT, TN and IT systems (IEC 61557-6)
EN 61557-8, Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. —
Equipment for testing, measuring or monitoring of protective measures — Part 8: Insulation monitoring
devices for IT systems (IEC 61557-8)
EN 61557-15, Electrical safety in low voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. -
Equipment for testing, measuring or monitoring of protective measures - Part 15: Functional safety
requirements for insulation monitoring devices in IT systems and equipment for insulation fault location in IT
systems (IEC 61557-15)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
mining operation / road heading

3.1.1
mining operation
a) in case of longwall mining: the face including the connected workings
Note 1 to entry: Connecting workings are up to 10 m on both sides of the face entrance. The face entrance is the area
between the face and the latest complete row of the roof support.
b) in case of other mining methods: the production area including the connected workings
Note 2 to entry: Connecting workings are up to 10 m to the heading face.
Note 3 to entry: In case of greater mining operation areas, e.g. salt industry, the mining authority will decide.
3.1.2
roadheading
parts of the underground workings where road heading activities are taking part up to 50 m far from the
roadhead
3.2
electrical installation
3.2.1
electrical power distribution
electrical installation with pieces of equipment used for such purposes as generation, conversion, storing,
transmission, distribution or utilization of electric energy for mechanical work, for generation of heat and light
or for electrochemical processes
3.2.2
switchgear
switching devices and their combination with associated control, measuring, protective and regulating
equipment, also assemblies of such devices and equipment with associated interconnections, accessories,
enclosures and supporting structures, intended in principle for use in connection with generation,
transmission, distribution and conversion of electric energy
[SOURCE: IEV 441-11-02]
3.2.3
electrical interference
influence of an electric power installation on a communication system or between different communication
systems depending on the coupling of capacitive, inductive or ohmic resistance
3.2.4
erection of electrical installation
new installation, redesign, extension, modification or reconstruction of an electrical installation
Note 1 to entry: Replacing of electrical equipment by similar one or reducing the electrical installation is not redesign if
the electrical parameters will not change substantially.
3.2.5
electrostatic earthing
electrical equipment which is electrostatically earthed, i.e. for which the leakage resistance against earth is not
bigger than a specific value
6 8
Note 1 to entry: The leakage resistance against earth should not be bigger than 10 Ω or bigger than 10 Ω if the
capacity is less or equal than 100 pF.
3.2.6
potential equalization in the field of intrinsically safe electrical systems and electric power
installations
elimination of potential differences between different protective conductors of electrical power installations and
between exposed conductive parts of intrinsically safe electrical systems
3.2.7
protective bonding conductor
protective conductor provided for protective-equipotential-bonding
[SOURCE: IEV 826-13-24]
3.2.8
communication system
installation for transmitting and processing of messages and/or information (e.g. speech, tunes, pictures or
characters) including remote control information (e.g. measuring values, messages or instructions)
Note 1 to entry: A communication system consists of broadcasting equipment, wireless or non-wireless transmission
path, receive terminal devices and the supplying equipment.
3.2.9
initial inspection
inspection of all electrical apparatus, systems and installations before they are brought into service
[SOURCE: IEV 426-14-06]
3.3
electrical equipment
3.3.1
electrical equipment
item used for such purposes as generation, conversion, transmission, distribution or utilization of electric
energy, such as electric machines, transformers, switchgear and controlgear, measuring instruments,
protective devices, wiring systems, current-using equipment
[SOURCE: IEV 826-16-01]
3.3.2
mobile electrical equipment
electric equipment which is moved while in operation or which can easily be moved from one place to another
while connected to the supply
[SOURCE: IEV 826-16-04]
3.3.3
current using equipment
electric equipment intended to convert electric energy into another form of energy, for example light, heat,
mechanical energy
[SOURCE: IEV 826-16-02]
3.3.4
hand-held equipment
electric equipment intended to be held in the hand during normal use
[SOURCE: IEV 826-16-05]
3.3.5
switch
device for changing the electric connections among its terminals
[SOURCE: IEV 151-12-22]
3.3.6
switchgear and controlgear
electric equipment intended to be connected to an electric circuit for the purpose of carrying out one or more
of the following functions: protection, control, isolation, switching
Note 1 to entry: The French and English terms can be considered as equivalent in most cases. However the French
terms have a broader meaning than the English terms and include for example connecting devices, plugs and sockets
outlets, etc. In English, these latter devices are known as accessories.
[SOURCE: IEV 826-16-03]
3.3.7
remote controlled switchgear
switchgear which is intended to switch on or off one or more electrical circuits by external activity, e.g.
mechanically, electrically, electro-optically, pneumatically, acoustically, or on a thermal or magnetic way and
where it is impossible to do it manually
3.3.8
convertor
set of equipment, static or rotating, to convert one type of electric current to another type different in nature,
voltage and/or frequency
[SOURCE: IEV 811-19-01]
3.4
intrinsic safety
3.4.1
intrinsically safe electrical system
assembly of interconnected items of electrical apparatus, described in a descriptive system document, in
which the circuits or parts of circuits, intended to be used in an explosive atmosphere, are intrinsically safe
circuits
[SOURCE: IEV 426-11-08]
3.4.2
intrinsically safe circuit
circuit in which any spark or any thermal effect produced in the conditions specified in EN 60079-11, including
normal operation and specified fault conditions, are not capable of causing ignition of a given explosive gas
atmosphere
[SOURCE: IEV 426-11-01]
3.4.3
intrinsically safe electrical apparatus
electrical apparatus in which all the circuits are intrinsically safe circuits
[SOURCE: IEV 426-11-02]
3.4.4
associated apparatus
electrical apparatus which contains both intrinsically safe circuits and non-intrinsically safe circuits and is
constructed so that the non-intrinsically safe circuits cannot adversely affect the intrinsically safe circuits
Note 1 to entry: Associated apparatus may be either:
a) electrical apparatus which has another type of protection listed in EN 60079–0 for use in the appropriate gas
atmosphere, or
b) electrical apparatus not so protected and which, therefore, shall be not used within an explosive gas atmosphere.
[SOURCE: IEV 426-11-03]
3.4.5
accessory
device supplementing a main device or apparatus, but not forming part of it, that is needed for its operation or
to confer on it specific characteristics
[SOURCE: IEV 151-11-24]
3.5
earthing
3.5.1
earthing system
arrangement of connections and devices necessary to earth equipment or a system separately or jointly
[SOURCE: IEV 604-04-02]
3.5.2
power system earthing
functional earthing and protective earthing of a point or points in an electric power system
[SOURCE: IEV 826-13-11]
3.5.3
earth
make an electric connection between a given point in a system or in an installation or in equipment and local
earth
Note 1 to entry: The connection to local earth maybe:
• intentional, or
• unintentional or accidental,
• and may be permanent or temporary.
[SOURCE: IEV 826-13-03]
3.5.4
earth-free exposed-conductive-part
exposed-conductive part without any connection to earth or other earth bounded electrical equipment
3.5.5
earth fault
occurrence of an accidental conductive path between a live conductor and the earth
[SOURCE: IEV 826-14-13 modified]
3.5.6
earth fault current
current flowing to earth due to an insulation fault
[SOURCE: IEV 442-01-23]
3.5.7
double earth fault
insulation faults to earth occurring simultaneously at two different locations in one or several circuits
originating from a common source
[SOURCE: IEV 604-02-22]
3.5.8
double earth fault current
current in case of a double earth fault
3.5.9
residual earth current
earth current at the point of fault after compensation
3.5.10
fault current
current which flows across a given point of fault resulting from an insulation fault
[SOURCE: IEV 826-11-11]
3.5.11
leakage current
electric current in an unwanted conductive path under normal operating conditions
[SOURCE: IEV 826-11-20]
3.5.12
functional earthing
earthing a point or points in a system or in an installation or in equipment for purposes other than electrical
safety
[SOURCE: IEV 826-13-10]
3.5.13
insulation fault
defect in the insulation of an electrical installation or of an equipment which can create a resistive path to earth
Note 1 to entry: The insulation fault can appear as a single fault from one line conductor or as a symmetrical fault from
all line conductors.
[SOURCE: IEV 604-02-02, modified]
3.5.14
Insulation Monitoring Device
IMD
device which permanently monitors the insulation resistance to earth of unearthed IT systems, independent
from the method of measuring
3.5.15
earth fault locking device
electrical device to monitor the insulation resistance of a non-alive system in order to prohibit a restart as long
as the insulation fault exists
3.5.16
exposed-conductive-part (of electrical equipment)
conductive part of equipment which can be touched and which is not normally live, but which can become live
when basic insulation fails
[SOURCE: IEV 826-12-10]
3.5.17
fault to frame
interconnection between exposed conductive parts and live parts of electrical equipment due to a fault
3.5.18
short-circuit
accidental or intentional conductive path between two or more conductive parts forcing the electric potential
differences between these conductive parts to be equal to or close to zero
[SOURCE: IEV 826-14-10]
3.5.19
total fault to frame, short-circuit or earth fault
resistance at the point of fault is nearly zero
3.6
wiring
3.6.1
flexible cable
cable supplying mobile electrical equipment
3.6.2
stationary cable
cable supplying stationary electrical equipment which is suitably fixed at e.g. roadway wall, roadway support,
conduits, platforms or constructional parts of machines
3.6.3
non-stationary cable
cable supplying electrical equipment which:
• are moved frequently or often,
• are moved as part of the mining or mineral winning process
3.7
conductors
3.7.1
line conductor
conductor which is energized in normal operation and capable of contributing to the transmission or
distribution of electric energy but which is not a neutral or mid-point conductor
[SOURCE: IEV 826-14-09]
3.7.2
neutral conductor
conductor electrically connected to the neutral point and capable of contributing to the distribution of electric
energy
[SOURCE: IEV 826-14-07]
3.7.3
protective conductor
conductor provided for purposes of safety, for example protection against electric shock
[SOURCE: IEV 826-13-22]
3.7.4
PEN conductor
conductor combining the functions of both a protective earthing conductor and a neutral conductor
[SOURCE: IEV 826-13-25]
3.8
switching
3.8.1
opening/tripping
opening of a circuit-breaker by either manual or automatic control of protective devices
Note 1 to entry: The expression tripping of a network item (line, transformer) in fact means tripping of the associated
circuit-breakers.
[SOURCE: IEV 604-02-31]
3.8.2
disconnection
making a circuit non-alive (opening of all lines)
3.8.3
isolation
general separation of an electrical equipment or circuit from all not earth bounded lines
3.9
protection against electrical shock

3.9.1
live part
conductor or conductive part intended to be energized in normal operation, including a neutral conductor, but
by convention not a PEN conductor
Note 1 to entry: This concept does not necessarily imply a risk of electric shock.
[SOURCE: IEV 826-12-08]
3.9.2
basic protection
protection against electric shock under fault-free conditions
Note 1 to entry: For low-voltage installations, systems and equipment, basic protection generally corresponds to
protection against direct contact.
[SOURCE: IEV 826-12-05]
3.9.3
fault protection
protection against electric shock under single-fault conditions
Note 1 to entry: For low-voltage installations, systems and equipment, fault protection generally corresponds to
protection against indirect contact, mainly with regard to failure of basic insulation.
[SOURCE: IEV 826-12-06]
3.9.4
basic insulation
insulation of hazardous-live-parts which provides basic protection
Note 1 to entry: This concept does not apply to insulation used exclusively for functional purposes.
[SOURCE: IEV 826-12-14]
3.9.5
protection by using equipment of protection class II or by equivalent insulation
safety precaution which is made by:
• an additional insulation of the basic insulation, or
• by strengthening of basic insulation,
in such a way that in a case of malfunction of basic insulation no dangerous situation will occur
3.9.6
Extra-Low Voltage
ELV
voltage not exceeding the relevant voltage limit of band I specified
...