1. Scope
This Standard defines the specific requirements for the design, selection and mounting of electrical installations in explosive gas atmospheres. These requirements are complementary to the requirements for electrical installations in non-hazardous areas.
This Standard applies to all electrical equipment and installations in hazardous areas whether permanent, temporary, movable, transportable or hand-held.
This Standard does not apply to:
— electrical installations under the shaft of mines;
Note： This standard may apply to electrical installations under the shaft of mines with other explosive gas other than firedamp and electrical installations on the ground of mines.
— electrical installations in areas where the hazard is due to combustible dusts or fibres;
— inherently explosive situations, for example explosive manufacturing and processing;
— room used for medical purpose.
Contents
Preface……………………………………………………………………………………
IEC Preface………………………………………………………………………………
IEC Introduction…………………………………………………………………………
1. Scope …………………………………………………………………………………
2． Cited Standards………………………………………………………………………
3． Definition………………………………………………………………………………
4. General Rules…………………………………………………………………………
4.1 General Requirements…………………………………………………………………
4.2 Documents……………………………………………………………………………
5. Selection of electrical apparatus (including cable and conduit)………………………
5.1 Specific documents……………………………………………………………………
5.2 Selection according to area classification……………………………………………
5.3 Selection according to ignition temperature of gas or vapor…………………………
5.4 Selection According To The Category Of Electrical Apparatus……………………
5.5 External Influences……………………………………………………………………
6. Prevention of hazardous spark……………………………………………………
6.1 hazard arising from active parts……………………………………………………
6.2 Hazard Arising From Bare External Conductor Components………………………
6.3 Isopotential connection……………………………………………………………
6.4 Static electricity……………………………………………………………………
6.5 Lightning-proof……………………………………………………………………
6.6 Electromagnetic radiation…………………………………………………………
6.7 Cathode protective metal parts……………………………………………………
7. Electrical protection………………………………………………………………
8. Emergency switch-off and electrical isolation…………………………………
8.1 Emergency switch-off……………………………………………………………
8.2 Electrical isolation…………………………………………………………………
9. Wiring system……………………………………………………………………
9.1 General……………………………………………………………………………
9.2 Cable system in Zone 0……………………………………………………………
9.3 Cable system in Zone 1&2…………………………………………………………
9.4 Conduit system……………………………………………………………………
10. Additional requirements for explosion-proof enclosure“d”……………………
10.1 Solid barrier ………………………………………………………………………
10.2 Protection Of Explosion-Proof Surface……………………………………………
10.3 Cable introducing system…………………………………………………………
10.4 Motor Powered By Frequency Conversion And Voltage Adjustment Power Supply…
10.5 Conduit system……………………………………………………………………
11. Complementary requirements for safety-increasing “e” explosion-proof type…
11.1 Protective class of enclosure………………………………………………………
11.2 Squirrel-cage induction motor—thermal protection during operation……………
11.3 Wiring system……………………………………………………………………
11.4 Resistance heater…………………………………………………………………
12. Additional requirements for intrinsic-safety “i” ………………………………
12.1 Introduction………………………………………………………………………
12.2. Installation in Zone 1 and Zone 2…………………………………………………
12.3 Installation in Zone 0………………………………………………………………
13. Complementary requirements for electrical apparatus of positive-pressure
type “p” ………………………………………………………………………
13.1 Piping……………………………………………………………………………
13.2 Measures To Be Taken For Positive-Pressure Failure……………………………
13.3 Multiple positive-pressure enclosures sharing one safety device………………
13.4 Purge……………………………………………………………………………
14. Complementary requirements for equipment used in Zone 2………………
14.1 Protective class of enclosure……………………………………………………
14.2 Energy limiting device and circuit………………………………………………
14.3 Wiring system……………………………………………………………………
14.4 Motor powered by frequency conversion and voltage adjustment power supply…
Appendix A (Appendix for this Standard) Inspection of intrinsic-safety circuit for
associated apparatus characterized by more than one linear current/voltage………
Appendix B (appendix for the prompt) Measurement methods of maximum current
and maximum voltage for intrinsic-safety circuit system of associated apparatus
characterized by more than one linear current/voltage………………………………
