IEC 60079-7:2006

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

This part of IEC 60079 specifies the requirements for the design, construction, testing and marking of electrical apparatus with type of protection increased safety "e" intended for use in explosive gas atmospheres. This standard applies to electrical apparatus where the rated voltage does not exceed 11 kV r.m.s. a.c. or d.c. Additional measures are applied to ensure that the apparatus does not produce arcs, sparks, or excessive temperatures in normal operation or under specified abnormal conditions.

Atmosphères explosives - Partie 7: Protection de l'équipement par sécurité augmentée <<e>>

La présente partie de la CEI 60079 décrit les exigences spécifiques de conception, de construction, d'essais et de marquage du matériel électrique avec mode de protection de sécurité augmentée "e" destiné à être utilisé dans les atmosphères explosives gazeuses. La présente norme s'applique au matériel électrique ayant une tension assignée ne dépassant pas 11 kV en courant alternatif (valeur efficace) ou en courant continu. Des mesures supplémentaires sont appliquées pour que le matériel ne produise ni arc, ni étincelle, ni température excessive en fonctionnement normal ou dans des conditions anormales spécifiées.

General Information

• Status: Published
• Publication Date: 09-Jul-2006
• ICS: 29.260.20 - Electrical apparatus for explosive atmospheres
• Technical Committee: TC 31 - Equipment for explosive atmospheres
• Drafting Committee: MT 60079-7 - TC 31/MT 60079-7
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 26-Jun-2015

Relations

• Revises: IEC 60079-7:2001 - Electrical apparatus for explosive gas atmospheres - Part 7: Increased safety "e"
• Effective Date: 05-Sep-2023
• Revised: IEC 60079-7:2015 - Explosive atmospheres - Part 7: Equipment protection by increased safety "e"
• Effective Date: 05-Sep-2023
• Revises: IEC 60079-7:2001/COR1:2004 - Corrigendum 1: Electrical apparatus for explosive gas atmospheres - Part 7: Increased safety "e"
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60079-7
Edition 4.0 2006-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 7: Equipment protection by increased safety "e"

Atmosphères explosives –
Partie 7: Protection de l'équipement par sécurité augmentée «e»

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IEC 60079-7
Edition 4.0 2006-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 7: Equipment protection by increased safety "e"

Atmosphères explosives –
Partie 7: Protection de l'équipement par sécurité augmentée «e»

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XC
CODE PRIX
ICS 29.260.20 ISBN 2-8318-8726-7

– 2 – 60079-7 © IEC:2006
CONTENTS
FOREWORD.5

1 Scope.7
2 Normative references .7
3 Terms and definitions .9
4 Constructional requirements for all electrical apparatus.12
4.1 General .12
4.2 Electrical connections.12
4.3 Clearances.15
4.4 Creepage distances.20
4.5 Solid electrical insulating materials.21
4.6 Windings .21
4.7 Temperature limitations .22
4.8 Wiring internal to apparatus.24
4.9 Degrees of protection provided by enclosures .24
4.10 Fasteners .24
5 Supplementary requirements for specific electrical apparatus.25
5.1 General .25
5.2 Rotating electrical machines.25
5.3 Luminaires .30
5.4 Caplights and handlights .34
5.5 Measuring instruments and instrument transformers.35
5.6 Transformers other than instrument transformers .35
5.7 Batteries.36
5.8 General purpose connection and junction boxes.42
5.9 Resistance heaters (other than trace heaters) .42
5.10 Other electrical apparatus .44
6 Type verifications and type tests .44
6.1 Dielectric strength .44
6.2 Rotating electrical machines.45
6.3 Luminaires designed for mains supply.47
6.4 Measuring instruments and instrument transformers.49
6.5 Transformers other than instrument transformers .50
6.6 Secondary batteries .50
6.7 General purpose connection and junction boxes.53
6.8 Resistance heating devices and resistance heating units .53
6.9 Terminal insulating material tests .54
7 Routine verifications and routine tests .55
7.1 Dielectric tests .55
7.2 Dielectric tests for batteries.55
7.3 Inter-turn overvoltage tests.56
8 Ex component certificates.56
8.1 General .56
8.2 Terminals .56

60079-7 © IEC:2006 – 3 –
9 Marking and instructions.56
9.1 General marking.56
9.2 Instructions for use.57
9.3 Warning markings .59

Annex A (normative) Cage motors − Methods of test and of calculation .60
Annex B (normative) Type tests for specific forms of resistance heating devices or
resistance heating units (other than trace heater) .62
Annex C (informative) Cage motors – Thermal protection in service.64
Annex D (informative) Resistance heating devices and units – Additional electrical
protection .65
Annex E (informative) Combinations of terminals and conductors for general purpose
connection and junction boxes .66
Annex F (informative) Dimensions of copper conductors .68
Annex G (informative) Potential stator winding discharge risk assessment – Ignition
risk factors.69
Annex H (normative) Test procedure for T8, T10 and T12 lamps.70
Annex I (Informative) Introduction of an alternative risk assessment method
encompassing ‘Equipment Protection Levels’ for Ex Equipment. .75

Bibliography.80

Figure 1 – Determination of creepage distances and clearances.20
Figure 2 – Minimum values of the time t of motors in relation to the starting current
E
ratio I /I .28
A N
Figure 3 – Arrangement for the luminaire vibration test .49
Figure A.1 – Diagram illustrating the determination of time t .61
E
Figure E.1 – Example of defined terminal/conductor arrangement table .67
Figure H.1 – Asymmetric pulse test circuit .71
Figure H.2 – Asymmetric power detection circuit.73
Figure H.3 – Flow Chart – Asymmetric power Test.74

Table 1 – Creepage distances and clearances .16
Table 2 – Tracking resistance of insulating materials .20
Table 3 – Limiting temperatures for insulated windings .23
Table 4 – Potential air gap sparking risk assessment for cage rotor ignition risk factors.27
Table 5 – Minimum distance between lamp and protective cover .31
Table 6 – Creepage distances and clearances for screw lamp caps .31
Table 7 − Resistance to the effect of short-circuit currents.35
Table 8 – Explosion test mixtures .46
Table 9 – Insertion torque and minimum removal torque .47
Table 10 – Value for pull-out tests .55
Table 11 – Creepage distances and clearances for screw lamp caps .58
Table 12 − Tex
...