IEC 61892-7:2007

Mobile and fixed offshore units - Electrical installations - Part 7: Hazardous areas

This part of IEC 61892 contains provisions for hazardous areas classification and choice of electrical installation in hazardous areas in mobile and fixed offshore units, including pipeline, pumping or 'pigging' stations, compressor stations and exposed location single buoy moorings, used in the offshore petroleum industry for drilling, processing and for storage purposes. This edition includes the following significant technical changes with respect to the previous edition: a) the clauses regarding area classification have been updated based on changes in IEC 60079 10; b) the clauses regarding emergency shut down have been updated, based on current industry practice; c) the clauses regarding installation have been updated based on changes in IEC 60079-14; d) a new clause regarding ventilation of battery compartment for valve regulated batteries has been added.

General Information

• Status: Published
• Publication Date: 20-Nov-2007
• ICS: 47.020.60 - Electrical equipment of ships and of marine structures
• Technical Committee: TC 18 - Electrical installations of ships and of mobile and fixed offshore units
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 11-Dec-2014

Relations

• Revised: IEC 61892-7:2014 - Mobile and fixed offshore units - Electrical installations - Part 7: Hazardous areas
• Effective Date: 05-Sep-2023
• Revises: IEC 61892-7:1997 - Mobile and fixed offshore units - Electrical installations - Part 7: Hazardous area
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61892-7
Edition 2.0 2007-11
INTERNATIONAL
STANDARD
Mobile and fixed offshore units – Electrical installations –
Part 7: Hazardous areas
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IEC 61892-7
Edition 2.0 2007-11
INTERNATIONAL
STANDARD
Mobile and fixed offshore units – Electrical installations –
Part 7: Hazardous areas
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XA
ICS 47.020.60 ISBN 2-8318-9393-3

– 2 – 61892-7 © IEC:2007(E)
CONTENTS
FOREWORD.6
INTRODUCTION.8

1 Scope.9
2 Normative references .9
3 Terms and definitions .10
4 Area classification .15
4.1 General .15
4.2 Safety principles.16
4.3 Sources of release .16
4.4 Type of zone .17
4.5 Relative density of the gas or vapour when it is released.17
4.6 Mobile drilling units .17
4.6.1 Zone 0.18
4.6.2 Zone 1.18
4.6.3 Zone 2.18
4.6.4 Well test facilities .18
4.7 Fixed production units .18
4.7.1 Zone 0.19
4.7.2 Zone 1.19
4.7.3 Zone 2.19
4.7.4 Drilling facilities .19
4.8 Mobile production units .19
4.9 Provisions regarding mobile and fixed offshore units .20
4.10 Openings, access and ventilation conditions affecting the extent of
hazardous areas.20
4.10.1 General .20
4.10.2 Enclosed space with direct access to any zone 1 location .20
4.10.3 Enclosed space with direct access to any zone 2 location .20
4.10.4 An enclosed space with direct access to any zone 1 location.20
4.10.5 Notices .21
5 Electrical systems .21
5.1 Sources of electrical power .21
5.2 Distribution systems .21
5.2.1 General .21
5.2.2 Earth fault detection .21
5.3 Electrical protection.21
5.4 Emergency conditions due to drilling operations – Mobile drilling units .22
5.5 Emergency switch-off – Ignition source control – Fixed production units.22
5.6 Protection from dangerous sparking .23
5.6.1 Dangers from live parts .23
5.6.2 Dangers from exposed and extraneous conductive parts .23
5.6.3 Potential equalization .24
5.6.4 Static electricity .24
5.6.5 Lightning protection .24
5.6.6 Cathodically protected metallic parts .25

61892-7 © IEC:2007(E) – 3 –
5.6.7 Electromagnetic radiation .25
5.7 Danger from rotating parts.25
6 Electrical equipment .25
6.1 General .25
6.2 Selection of electrical apparatus.25
6.2.1 Selection with respect to area classification.25
6.2.2 Selection with respect to ignition temperature of the gas or vapour.25
6.2.3 Selection according to apparatus grouping .26
6.2.4 External influences .26
6.2.5 Ambient temperature .27
6.3 Electrical apparatus in hazardous areas .27
6.3.1 Equipment for zone 0 .27
6.3.2 Equipment for zone 1 .27
6.3.3 Equipment for zone 2 .27
6.3.4 Apparatus with multiple types of protection.28
6.4 Selection of apparatus not available in accordance with IEC standards .28
6.5 Portable apparatus .28
7 Installation.29
7.1 General .29
7.2 Selection of apparatus.29
7.3 Wiring system – General .29
7.4 Connections .30
7.5 Unused openings .30
7.6 Circuits traversing a hazardous area .30
7.7 Unused cores .30
7.8 Cable surface temperature .30
7.9 Jointing .30
7.10 Cable wiring systems .31
7.11 Conduit systems.31
7.12 Mixed systems .32
7.13 Apparatus in hazardous areas .33
7.14 Wiring system in zone 0 .33
7.15 Intrinsically safe electrical installations.34
7.16 Simple apparatus .35
7.17 Verification of intrinsically safe circuits .36
7.18 Additional requirements for type of protection “d” – Flameproof enclosures .36
7.18.1 General .36
7.18.2 Solid obstacles .36
7.18.3 Protection of flameproof joints .36
7.18.4 Cable entry system.37
7.19 Additional requirements for type of protection “e” – Increased safety.39
7.19.1 Cable entry for Ex e equipment .39
7.19.2 Cage induction motors – Overload protection .39
7.19.3 Motors – Varying frequency and voltage .40
7.20 Additional requirements for type of pressurization “p” – Pressurized
apparatus .40
7.20.1 General .40
7.20.2 Ducting.41

– 4 – 61892-7 © IEC:2007(E)
7.20.3 Action to be taken on failure of pressurization – Apparatus without an
internal source of release .41
7.20.4 Purging.42
7.21 Resistance-heating devices.43
8 Ventilation .43
8.1 General .43
8.2 Ventilation of spaces containing electrical apparatus.44
8.3 Ventilation and operation of rooms or buildings protected by pressurization .44
8.4 Values of overpressure and of protective gas flow.45
8.5 Failure of the pressurization .45
8.6 Ventilation of battery compartments .46
8.6.1 Stationary batteries – Vented and valv
...