Erection of electrical installations in underground mines

This European standard EN 50628 specifies the safety requirements for the erection of electrical installations.
This standard is supplementary to other relevant harmonized standards, for example HD 60364 series and EN 61936-series as regards electrical installation requirements.
This part also refers to EN 60079-0 and its associated standards for the construction, testing and marking requirements of suitable electrical equipment.
EN 60079-14 standard gives the specific requirements for design, selection and erection of electrical installations in explosive atmospheres.
NOTE 1   EN 60079-14 standard 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.
NOTE 2   For next edition of EN6079-14 installation requirements for mining equipment might be implemented.
This 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,
•   Telecommunication installation of hoisting and inclined haulage plants,
•   Intrinsically safe electrical installations of above ground installation being part of underground workings,
•   Remote control systems if they have to fulfil increased requirements relating to functional safety,
•   Electrical installation and electrical equipment of ventilation systems and shaft casings above ground being endangered by methane of the underground ventilation,
•   Methane 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 of all underground workings.

Errichten elektrischer Anlagen im Bergbau unter Tage

Diese Europäische Norm EN 50628 regelt die Sicherheitsanforderungen für die zu errichtenden elektrischen Anlagen.
Diese Norm ergänzt andere relevante harmonisierte Normen, sofern sie die elektrische Installation betreffen; z. B. die Serie der Harmonisierungsdokumente HD 60364 sowie die Reihe EN 61936.
Diese Norm referenziert zudem auf die Normenreihe EN 60079 sowie der zugehörigen Normen hinsichtlich der Konstruktion, der Prüfung sowie der Kennzeichnung geeigneter elektrischer Betriebsmittel.
Die Norm EN 60079 14 zeigt spezielle Anforderungen auf hinsichtlich dem Design, der Auswahl sowie der elektrischen Installation in explosionsfähigen Atmosphären.
ANMERKUNG 1   EN 60079 14 kann zutreffen für elektrische Installationen in Bergwerken, wo sich explosionsfähige Atmosphären bilden können, die nicht aus Methan bestehen, sowie bei Übertageinstallationen von Bergwerken.
ANMERKUNG 2   Im Zuge der nächsten Ausgabe der EN 60079 14 ist es möglich, dass die Anforderungen an Bergbau-Betriebsmittel mit aufgenommen werden.
Diese Norm gilt für das Errichten
a)   von elektrischen Anlagen im Bergbau unter Tage;
b)   von elektrischen Anlagen und von Teilen elektrischer Anlagen über Tage, die bei Untrennbarkeit der Arbeits- und Betriebsvorgänge funktionell und sicherheitstechnisch mit dem Untertagebetrieb unmittelbar zusammenhängen.
   Derartige Anlagen und Teile sind insbesondere:
–   Schutzorgane und Überwachungseinrichtungen für die Energieversorgungsnetze unter Tage;
–   Fernmeldeanlagen für Schacht- und Schrägförderanlagen;
–   zu Tage führende elektrische Anlagen mit eigensicheren Stromkreisen;
–   Fernwirkanlagen, wenn sie bestimmungsgemäß erhöhte Anforderungen an die Funktionssicherheit erfüllen müssen;
–   elektrische Anlagen und elektrische Betriebsmittel für Lüfteranlagen und Schachtschleusen in übertä-gigen Bereichen, die durch das von den Wettern des Untertagebetriebs mitgeführte Grubengas gefährdet werden können;
–   Grubengasabsauganlagen;
c)   von elektrischen Anlagen unter Tage außerhalb des Bergbaus, wenn dies von der zuständigen Behörde oder der zuständigen Berufsgenossenschaft gefordert wird.
Nationale Vorschriften der Bergbehörden bleiben unberührt.
Diese Norm gilt für Installationen innerhalb aller Spannungsebenen nach Abschnitt 10.
Die über beide Spalten geschriebenen Anforderungen gelten für alle Grubenbaue.

Construction des installations électriques dans les mines souterraines

La présente Norme européenne spécifie les exigences de sécurité concernant la construction de nouvelles installations électriques.
La présente Norme européenne complète les autres normes harmonisées pertinentes, par exemple, la série HD 60364 et la série EN 61936 concernant les exigences relatives aux installations électriques.
La présente Norme européenne fait aussi référence à l'EN 60079-0 et à ses normes associées pour les exigences relatives à la construction, aux essais et au marquage des matériels électriques appropriés.
L’EN 60079-14 indique les exigences spécifiques concernant la conception, la sélection et la construction des installations électriques dans les atmosphères explosives.
NOTE   L'EN 60079-14 peut s’appliquer aux installations électriques situées dans des mines qui peuvent générer des atmosphères explosives sous forme de gaz autres que du grisou, et aux installations électriques situées dans les sites de surface des mines.
La présente Norme européenne s’applique aux:
a)   installations électriques dans les exploitations minières souterraines;
b)   installations électriques et aux parties d'installations électriques aériennes directement liées aux exploitations souterraines en ce qui concerne les questions de fonctionnement et de sécurité dans la mesure où elles font partie intégrante du procédé d'exploitation souterraine:
Il s'agit notamment:
-   des dispositifs de sécurité et de contrôle relatifs à la distribution d'alimentation des exploitations souterraines,
-   des systèmes de communication des équipements d'extraction et de convoyage inclinés,
-   des installations électriques de sécurité intrinsèque de l'installation aérienne partie intégrante des exploitations souterraines,
-   des systèmes de commande à distance s'ils doivent satisfaire aux exigences renforcées relatives à la sécurité fonctionnelle,
-   de l'installation électrique et des matériels électriques des systèmes d'aérage et des chemises d'arbres aériens menacés par la présence du grisou dans le système d'aérage souterrain,
-   des systèmes de captage du grisou;
c)   installations électriques des exploitations souterraines hors extraction si les autorités nationales compétentes l'exigent.
Les règlements nationaux des autorités minières ne doivent pas être affectés.
La présente norme s'applique aux installations à toutes les tensions mentionnées à l’Article 10.
Les exigences qui précèdent les deux colonnes sont des exigences qui concernent toutes les exploitations souterraines.
Mines grisouteuses
Les exigences indiquées dans la colonne de gauche sont des exigences qui concernent les exploitations souterraines de l'industrie de l'extraction du charbon qui peuvent être menacées par le grisou.
Autres mines
Les exigences indiquées dans la colonne de droite sont des exigences qui concernent les exploitations souterraines de l'industrie de l'extraction du charbon non susceptibles d'être menacées par le grisou, ainsi que les exploitations souterraines de l'industrie autre que celle de l'extraction du charbon.

Namestitev električnih inštalacij v podzemnih rudnikih

Ta evropski standard EN 50628 določa varnostne zahteve za namestitev električnih inštalacij.
Ta standard je dopolnilo k drugim zadevnim usklajenim standardom, na primer skupinama standardov HD 60364 in EN 61936, kar zadeva zahteve glede električnih inštalacij.
Ta del se nanaša na EN 60079-0 in njegove povezane standarde za zahteve za konstrukcijo, preskušanje in označevanje primerne električne opreme.
Standard EN 60079-14 podaja posebne zahteve za načrtovanje, izbiro in namestitev električnih inštalacij v eksplozivnih atmosferah.
OPOMBA 1: Standard EN 60079-14 se lahko uporablja za električne inštalacije v rudnikih, kjer lahko nastanejo eksplozivne plinske atmosfere, ki niso jamski eksplozivni plin, in za električne inštalacije v površinskih napeljavah rudnikov.
OPOMBA 2: Za naslednjo izdajo standarda EN6079-14 bodo morda uvedene zahteve za rudarsko opremo.
Ta standard se uporablja za:
a) Električne inštalacije v podzemnih deloviščih rudnikov.
b) Nadzemne električne inštalacije in dele električnih inštalacij, ki so neposredno povezani s podzemnimi delovišči v funkcionalnih in varnostnih zadevah, ker so del podzemnega delovnega procesa.
Vključujejo predvsem
• varnostne in nadzorne naprave, povezane z napajalnim omrežjem podzemnih delovišč,
• telekomunikacijske naprave dvižnih in nagnjenih transportnih obratov,
• lastnovarne električne inštalacije nadzemnih naprav, ki so del podzemnih delovišč,
• sisteme daljinskega vodenja, če morajo izpolnjevati strožje zahteve glede funkcionalne varnosti,
• električne inštalacije in električno opremo prezračevalnih sistemov in nadzemnih ohišij jaškov, ki jih ogroža metan podzemnega prezračevanja,
• metanske drenažne sisteme.
c) Električne inštalacije v podzemnih deloviščih zunaj rudarstva, če to zahtevajo pristojni nacionalni organi.
Nacionalni predpisi organov s področja rudarjenja ostanejo nespremenjeni.

General Information

Status
Published
Public Enquiry End Date
30-Jan-2015
Publication Date
08-Sep-2016
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
29-Jul-2016
Due Date
03-Oct-2016
Completion Date
09-Sep-2016

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SLOVENSKI STANDARD
SIST EN 50628:2016
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
SIST EN 50628:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 50628:2016

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SIST EN 50628:2016


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

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SIST EN 50628:2016
EN 50628:2016
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
2

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SIST EN 50628:2016
EN 50628:2016
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
3

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SIST EN 50628:2016
EN 50628:2016
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


4

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SIST EN 50628:2016
EN 50628:2016
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.
5

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SIST EN 50628:2016
EN 50628:2016
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.
6

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SIST EN 50628:2016
EN 50628:2016
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.
7

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SIST EN 50628:2016
EN 50628:2016
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)
8

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SIST EN 50628:2016
EN 50628:2016
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
...

SLOVENSKI STANDARD
oSIST prEN 50628:2015
01-januar-2015
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: prEN 50628:2014
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
oSIST prEN 50628:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 50628:2015

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oSIST prEN 50628:2015

EUROPEAN STANDARD DRAFT
prEN 50628
NORME EUROPÉENNE

EUROPÄISCHE NORM

November 2014
ICS
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 draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2015-04-10.

It has been drawn up by CLC/TC 31.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CENELEC 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.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.



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
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 24905 Ref. No. prEN 50628:2014 E

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1 Contents
2 Foreword . 5
3 1 Scope . 7
4 2 Normative references . 8
5 3 Terms and definitions . 9
6 3.1 Mining operation / Road heading . 9
7 3.2 Electrical installation . 10
8 3.3 Electrical equipment . 11
9 3.4 Intrinsic safety . 12
10 3.5 Earthing . 12
11 3.6 Wiring . 14
12 3.7 Conductors . 14
13 3.8 Switching . 15
14 3.9 Protection against electrical shock . 15
15 3.10 Voltages . 17
16 3.11 Electrical circuits . 18
17 3.12 Overcurrent . 18
18 3.13 overcurrent device . 18
19 4 General . 19
20 4.1 General requirements . 19
21 4.2 Initial verification . 20
22 4.3 Competence of personnel . 21
23 4.4 Documentation . 21
24 5 Means of protection against electric- and electrostatic charging . 21
25 6 Rooms and Locations . 21
26 6.1 Electrical service rooms . 21
27 6.2 Closed electrical service rooms . 22
28 6.3 Other rooms . 22
29 7 Protection against fire spreading . 22
30 7.1 General requirements . 22
31 8 Insulation, Insulation-resistance and its check . 23
32 8.1 Insulation . 23
33 8.2 Value of insulation resistance . 23
34 8.3 Insulation resistant check . 23
35 9 Signboards, labels, wiring diagrams, inscriptions . 24
36 9.1 General requirements . 24
37 10 Nominal voltages . 25
38 10.1 General requirements . 25
39 10.2 Voltage ranges . 26
40 11 Protection against electrical shock . 26
41 11.1 Requirements for basic protection . 26
42 11.2 Requirements for fault protection . 27
43 12 Protection in IT-Systems . 27
44 12.1 Earth fault detection in IT-systems . 28
45 12.2 Design of IT system . 28
46 12.3 Insulation monitoring . 29
47 12.4 Protective conductor . 30
48 12.5 Electrical protection devices in IT-systems . 32
49 12.6 Design of cables being monitored by a protection device . 35
50 13 Protection in TN-systems . 37
51 13.1 TN-S- systems with residual current devices (RCD) . 37
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52 13.2 TN-S System without residual current devices (RCD) . 37
53 14 Other means of protection . 38
54 15 Protection against danger caused by mechanical influence on non-intrinsically safe
55 cables. 38
56 15.1 General requirements . 38
57 15.2 Cables to supply mobile electrical equipment . 39
58 15.3 Cable in areas of mining activities or road heading areas till 50m far from the road
59 heading face . 40
60 16 Intrinsically safe electrical systems . 40
61 16.1 General requirements for selection . 40
62 16.2 Descriptive system document . 40
63 16.3 Erection . 40
64 16.4 Separation of intrinsically and none intrinsically safe circuits . 41
65 16.5 Separation of different intrinsically safe circuits . 42
66 16.6 Earthing . 42
67 16.7 Cable for intrinsically safe systems . 42
68 17 Installation of Transformers . 42
69 18 Substations . 42
70 19 Disconnecting devices in line of each switch-gears . 43
71 20 Switchgears . 43
72 21 Couplers and connectors . 43
73 21.1 General requirements for use of couplers and connectors . 43
74 21.2 Additional requirements using couplers . 43
75 22 Luminaries and lighting installation . 44
76 23 Cables . 44
77 23.1 Design of cables . 44
78 23.2 Conductor materials . 45
79 23.3 Current carrying capacity . 45
80 23.4 Coverings and outer protective covers. 45
81 23.5 Different circuits within one cable . 46
82 23.6 Laying out of cables . 46
83 23.7 Leading in and connecting of cables . 47
84 23.8 Laying out of non-insulated conductors . 48
85 23.9 Additional requirements for the use of single core cable . 49
86 24 Protection of electrical equipment or installation against overcurrent . 49
87 24.1 Overcurrent protection devices . 49
88 24.2 Overload protection . 50
89 24.3 Short circuit protection . 50
90 24.4 Minimum short circuit current . 51
91 25 Calculation of short circuit currents . 51
92 26 Additional requirements for systems and equipment with nominal voltage of more than
93 1 kV up to 6.6 kV in production areas and road heading . 52
94 26.1 General requirements . 52
95 26.2 Switchgears . 52
96 26.3 Test of insulation resistance of non-alive cable in production areas and road headings . 52
97 26.4 Insulation monitoring of alive systems . 53
98 26.5 Earth protection in IT systems . 53
99 26.6 Monitoring of non-alive systems . 53
100 26.7 Electrical protection devices for feeding cables of electrical equipment . 54
101 26.8 Cabledesign . 54
102 27 Additional requirements for cable entry selection . 54
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103 Annex A (informative) Documentation . 55
104 Annex B (normative) . 56
105 Annex C (informative) Example for a galvanically separated system (in production areas or road
106 headings) . 58
107 Annex D (informative) Example for calculation (according to 12.2.6) . 59
108 Annex E (informative) Table for cables suitable for underground workings . 64
109 Annex F (informative) Table for current carrying capacity of cables suitable for underground
110 workings . 69
111 Bibliography . 71
112
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113 Foreword
114 This document (prEN 50628:2014) was prepared by CLC/TC 31 WG11 “Electrical apparatus for potentially
115 explosive atmospheres - Safety requirements for the erection of electrical installations in underground mines”.
116 This document is currently submitted to the enquiry.
117 This document is to be read in conjunction with the European Standards for the specific types of protection
118 listed in EN 60079 series of standards.
119 This document is also to be read in conjunction with EN 1127-2:2010.
120 This document has been prepared under a mandate given to CENELEC by the European Commission and
1)
121 the European Free Trade Association, and supports essential requirements of EU Directive .

1)
For the relationship with EU Directive, TC 31 is supposed to provide an Annex ZZ for the ATEX directive before voting
stage.
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122 Introduction
123 When electrical equipment is to be installed in underground workings where dangerous concentration of
124 methane may be present in the atmosphere protective measures are applied to avoid the ignition of firedamp
125 either under normal operation of the electrical installation or under fault conditions.
126 Mines can be either gassy or non-gassy depending upon the mineral/material being extracted and whether or
127 not firedamp can occur in the workings. It is usual practice to consider all coal mines as gassy mines. Non-
128 coal mines can however, also be susceptible to the occurrence of firedamp e. g. if they are mining
129 minerals/materials in the vicinity of oil bearing strata or unworked coal seams which are to be disturbed by the
130 mining process, or are susceptible to outbursts of flammable gas.
131 Due to the fact that in underground workings firedamp is the main hazard that is to be considered all pieces of
132 electrical equipment are to be selected with regard to this hazard. If there are other significant explosive
133 atmospheres than firedamp the hazard occurring from these explosive atmospheres are to be taken into
134 account.
135 Directive 2014/34/EU extends the definition of potentially explosive atmosphere to include combustible dust as
1
136  has shown that the minimum ignition energy (MIE) of coal dust/ air
well as firedamp. Extensive research
137 mixture is several hundred times higher than that of a firedamp/ air mixture and that the maximum
138 experimental safe gap (MESG) for coal dust particles is more than double that for firedamp. It is therefore
139 reasonable to assume that equipment, protective systems and components that are designed and constructed
140 for use in firedamp/ air mixtures are also suitable for use in coal dust/ air mixtures.
141 Unlike group II it is to be assumed that in group I industry nearly all underground workings are to be classified
142 as hazardous areas. A zone classification for such underground workings is not possible because the degree
143 of exposure of such an underground working doesn´t depend on local parameters but on time parameters. In
144 accordance with 2014/34/EU (ATEX-Directive) the exposure of the installed equipment may change from
145 normally acceptable methane concentration in the mine air (hazardous condition 2; M2 equipment sufficient)
146 to elevated methane concentration (hazardous condition 1; M1 equipment required, M2 equipment to be de-
147 energized) and vice versa.
148 Areas of a coal mine could be non-hazardous according to national regulations. In such areas equipment that
149 is not ATEX approved may be used subject to the risk assessment and maybe associated rules.
150 In non-gassy mines it can be possible that in certain regions in the underground workings explosive
151 atmospheres can occur. In these cases national regulations will apply.
152 In mines where the atmosphere, in addition to firedamp, may contain significant proportions of other
153 flammable gases than methane, the installed Group I equipment complies also with the subdivision of Group II
154 corresponding to the other significant flammable gases.
155 In any underground working, irrespective of the size, there may be numerous sources of ignition apart from
156 those associated with electrical equipment. Precautions may be necessary to ensure safety from other
157 possible ignition sources, but guidance on this aspect is outside the scope of this standard.
158 Underground mining activities cause other special problems to the electrical installation as well than arising
159 from firedamp. Rough environmental conditions evoked by climate – temperature and humidity e.g. – rock
160 pressure caused by depth, geometric dimensions of the underground workings, the winning process itself and
161 other similar circumstances require therefore special specifications to the electrical installation in underground
162 mines.

1 Survey on the use of flameproof enclosures in coal dust and methane atmospheres, G. A. Lunn, SM/97/01.
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163 1 Scope
164 This European standard EN 50628 specifies the safety requirements for the erection of electrical installations.
165 This standard is supplementary to other relevant harmonized standards, for example HD 60364 series and
166 EN 61936-series as regards electrical installation requirements.
167 This part also refers to EN 60079-0 and its associated standards for the construction, testing and marking
168 requirements of suitable electrical equipment.
169 EN 60079-14 standard gives the specific requirements for design, selection and erection of electrical
170 installations in explosive atmospheres.
171
172 NOTE 1  EN 60079-14 standard can apply to electrical installations in mines where explosive gas atmospheres other than
173 firedamp can be formed and to electrical installations in the surface installation of mines.
174 NOTE 2  For next edition of EN6079-14 installation requirements for mining equipment might be implemented.
175 This standard applies to
176 a) Electrical installation in underground workings of mines.
177 b) Electrical installations and parts of electrical installation above ground, which are directly connected with
178 the underground workings in functional and safety relating matters because of being part of the
179 underground working process.
180 These are in particular
181 • Safety and monitoring devices relating to the power distribution of the underground workings,
182 • Telecommunication installation of hoisting and inclined haulage plants,
183 • Intrinsically safe electrical installations of above ground installation being part of underground
184 workings,
185 • Remote control systems if they have to fulfil increased requirements relating to functional safety,
186 • Electrical installation and electrical equipment of ventilation systems and shaft casings above ground
187 being endangered by methane of the underground ventilation,
188 • Methane drainage systems.
189 c) Electrical installation in underground workings outside mining if it is demanded of the competent national
190 authorities.
191 National regulations of the mining authority shall remain unaffected.
192 This standard applies to installations at all voltages mentioned in Clause 10.
193 Requirements above both columns are requirements of 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
none coal mining industry.
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194
195 2 Normative references
196 The following documents, in whole or in part, are normatively referenced in this document and are
197 indispensable for its application. For dated references, only the edition cited applies. For undated references,
198 the latest edition of the referenced document (including any amendments) applies.
Test methods and requirements for accessories for use on distribution cables of
EN 50393
rated voltage 0.6/1.0 (1.2) kV
EN 60038 CENELEC standard voltages
EN 60079-0 Explosive atmospheres - Part 0: Equipment - General requirements
EN 60079-7 Explosive atmospheres - Part 7: Equipment protection by increased safety "e"
EN 60079-10-1 Explosive atmospheres - Part 10-1: Classification of areas - Explosive gas
atmospheres
EN 60079-10-2 Explosive atmospheres - Part 10-2: Classification of areas - Explosive dust
atmospheres
EN 60079-11 Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i"
EN 60079-14 Explosive atmospheres - Part 14: Electrical installations design, selection and
erection
Explosive atmospheres - Part 25: Intrinsically safe electrical systems
EN 60079-25
EN 60204-1 Safety of machinery - Electrical equipment of machines - Part 1: General
requirements
EN 60296 Fluids for electrotechnical applications - Unused mineral insulating oils for
transformers and switchgear
EN 60309-1 Plugs, socket-outlets and couplers for industrial purposes - Part 1: General
requirements
EN 60332-1-1 Tests on electric and optical fibre cables under fire conditions - Part 1-1: Test for
vertical flame propagation for a single insulated wire or cable - Apparatus
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
Tests on electric and optical fibre cables under fire conditions. Test for vertical
EN 60332-2-1
flame propagation for a single small insulated wire or cable. Apparatus
EN 60332-2-2 Tests on electric and optical fibre cables under fire conditions - Part 2-2: Test for
vertical flame propagation for a single s
...

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