prEN IEC 60079-7:2024

SLOVENSKI STANDARD
01-februar-2024
Eksplozivne atmosfere - 7. del: Zaščita opreme s povečano varnostjo "e"
Explosive atmospheres - Part 7: Equipment protection by increased safety "e"
Explosionsgefährdete Bereiche - Teil 7: Geräteschutz durch erhöhte Sicherheit "e"
Atmosphères explosives - Partie 7: Protection du matériel par sécurité augmentée "e"
Ta slovenski standard je istoveten z: prEN IEC 60079-7:2023
ICS:
29.260.20 Električni aparati za Electrical apparatus for
eksplozivna ozračja explosive atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

31/1748/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60079-7 ED6
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-12-08 2024-03-01
SUPERSEDES DOCUMENTS:
31/1669/CD, 31/1694A/CC
IEC TC 31 : EQUIPMENT FOR EXPLOSIVE ATMOSPHERES
SECRETARIAT: SECRETARY:
United Kingdom Mr Tom Stack
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

Other TC/SCs are requested to indicate their interest, if any,
in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
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The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
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Recipients of this document are invited to submit, with their comments, notification of any relevant “In So me Countries”
clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for
submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Explosive atmospheres - Part 7: Equipment protection by increased safety "e"

PROPOSED STABILITY DATE: 2027
NOTE FROM TC/SC OFFICERS:
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

IEC CDV 60079-7 ED6 © IEC 2023 -2- 31/1748/CDV

1 CONTENTS
2 CONTENTS . 1
3 FOREWORD . 8
4 1 Scope . 16
5 2 Normative references . 17
6 3 Terms and definitions . 19
7 4 Construction requirements . 23
8 4.1 Level of Protection . 23
9 4.2 Electrical connections . 24
10 4.2.1 General . 24
11 4.2.2 Field wiring connections . 25
12 4.2.3 Factory connections . 26
13 4.2.4 External plug and socket-outlet connections for field wiring connection . 28
14 4.3 Insulation coordination . 29
15 4.3.1 Environmental conditions . 29
16 4.3.2 Creepage distances . 31
17 4.3.3 Separation distances. 32
18 4.4 Printed circuit boards with coating, Level of Protection “ec” . 37
19 4.5 Solid electrical insulating materials. 38
20 4.5.1 General . 38
21 4.5.2 Specification . 38
22 4.5.3 Long-term thermal stability . 39
23 4.6 Windings . 39
24 4.6.1 General . 39
25 4.6.2 Insulated conductors . 39
26 4.6.3 Winding impregnation . 39
27 4.6.4 Conductor dimensions . 40
28 4.6.5 Sensing elements . 40
29 4.7 Limiting temperature. 40
30 4.7.1 General . 40
31 4.7.2 Conductors . 41
32 4.7.3 Insulated windings . 41
33 4.8 Wiring internal to equipment . 42
34 4.9 Degree of protection (IP Code) provided by enclosures . 42
35 4.9.1 General . 42
36 4.9.2 Drain holes or ventilation openings . 42
37 4.9.3 Live maintenance – Type of Protection “i” circuits or apparatus . 43
38 4.10 Fasteners . 43
39 5 Supplementary requirements for specific electrical equipment . 43
40 5.1 General . 43
41 5.2 Electric machines . 43
42 5.2.1 General . 43
43 5.2.2 Degrees of protection provided by electric machines, Level of Protection “eb”44
44 5.2.3 Degrees of protection provided by electric machines, Level of Protection “ec”44
45 5.2.4 Connection facilities for external conductors . 44
46 5.2.5 Internal cooling fans . 45
47 5.2.6 Minimum acceptable air gap . 45

IEC CDV 60079-7 ED6 © IEC 2023 – 3 – 31/1748/CDV

48 5.2.7 Rotating electric machines with cage rotors . 46
49 5.2.8 Determination of limiting temperature . 48
50 5.2.9 Machines with permanent magnet rotors . 52
51 5.2.10 Stator winding insulation system . 53
52 5.2.11 Supplemental winding requirements Level of Protection “eb” . 53
53 5.2.12 Bearing seals and shaft seals for Level of Protection “eb” . 53
54 5.2.13 Neutral point connections . 54
55 5.2.14 Anti-condensation heaters . 54
56 5.3 Luminaires, hand lights, or caplights . 55
57 5.3.1 General . 55
58 5.3.2 Light source . 55
59 5.3.3 Minimum distance between lamp and protective cover . 56
60 5.3.4 Electrical spacings . 57
61 5.3.5 Lampholders and lamp caps . 57
62 5.3.6 Auxiliaries for Luminaires in Level of Protection “ec” . 60
63 5.3.7 Surface temperatures . 61
64 5.3.8 Limiting temperatures. 62
65 5.3.9 Luminaires for tubular fluorescent bi-pin lamps . 62
66 5.3.10 Tests for resistance to impact . 63
67 5.4 Analog measuring instruments and instrument transformers . 64
68 5.4.1 General . 64
69 5.4.2 Limiting temperature . 64
70 5.4.3 Short-circuit currents . 64
71 5.4.4 Short time thermal current . 64
72 5.4.5 Measuring instruments supplied by current transformers . 64
73 5.4.6 Moving coils . 64
74 5.4.7 External secondary circuits . 64
75 5.5 Transformers other than instrument transformers . 65
76 5.6 Supplementary requirements for equipment incorporating cells and batteries . 65
77 5.6.1 Type of cells and batteries . 65
78 5.6.2 Requirements for cells and batteries 25 Ah . 67
79 5.6.3 Requirements for valve-regulated or vented cells or batteries 25 Ah . 69
80 5.6.4 Charging of cells and batteries . 73
81 5.7 Enclosures . 74
82 5.7.1 General purpose connection and junction boxes . 74
83 5.7.2 “ec” Ex Equipment enclosures . 74
84 5.8 Partially enclosed Ex Equipment in Level of Protection “ec”. 74
85 5.8.1 General . 74
86 5.8.2 Degree of protection (IP Code) requirements for Partially enclosed Ex
87 Equipment that is mounted in an “ec” Ex Equipment enclosure . 74
88 5.8.3 Degree of protection (IP Code) requirements for Partially enclosed Ex
89 Equipment that is used to complete the “ec” Ex Equipment enclosure . 74
90 5.9 Low-voltage switchgear and controlgear assemblies . 75
91 5.10 Resistance heating equipment (other than trace heating systems) . 75
92 5.10.1 General . 75
93 5.10.2 Heating resistors . 75
94 5.10.3 Temperature coefficient . 75
95 5.10.4 Insulating material . 75
96 5.10.5 Cold-start current . 75

IEC CDV 60079-7 ED6 © IEC 2023 -4- 31/1748/CDV

97 5.10.6 Electrical safety device . 75
98 5.10.7 Electrically conductive covering . 76
99 5.10.8 Exclusion of explosive atmosphere . 76
100 5.10.9 Conductor cross-section. 76
101 5.10.10 Limiting temperature . 76
102 5.10.11 Safety device .
...