GB/T 3836.4-2021Explosive atmospheres - Part 4: Equipment protection by intrinsic safety 'i' (English PDF)

Foreword

This Document was drafted as per the rules specified in GB/T 1.1-2020 Directives for

Standardization - Part 1.Rules for the Structure and Drafting of Standardizing

Documents.

This Document is Part 4 of GB/T 3836 Explosive Atmospheres. GB/T 3836 has

published the following parts.

--- Part 1.Equipment - General Requirements;

--- Part 2.Equipment Protection by Flameproof Enclosure "d";

--- Part 3.Equipment Protection by Increased Safety "e";

--- Part 4.Equipment Protection by Intrinsic Safety "i";

--- Part 5.Equipment Protection by pressurized Enclosure "p";

--- Part 6.Equipment Protection by Liquid Immersion "o";

--- Part 7.Equipment Protection by Powder Filling "q";

--- Part 8.Equipment Protection by Type of Protection "n";

--- Part 9.Equipment Protection by Encapsulation "m";

--- Part 11.Material Characteristics for Gas and Vapour Classification - Test

Methods and Data;

--- Part 12.Material Characteristics for Combustible Dusts - Test Methods;

--- Part 13.Equipment Repair, Overhaul, Reclamation and Modification;

--- Part 14.Classification of Areas - Explosive Gas Atmosphere;

--- Part 15.Electrical Installations Design, Selection and Erection;

--- Part 16.Electrical Installations Inspection and Maintenance;

--- Part 17.Equipment Protection by Pressurized Room "p" and Artificially Ventilated

Room "v";

--- Part 18.Intrinsically Safe Electrical Systems;

--- Part 20.Equipment with Equipment Protection Level (EPL) Ga;

--- Part 21.Application of Quality Systems for Equipment Manufacture;

--- Part 22.Protection of Equipment and Transmission System Using Optical

Radiation;

--- Part 23.Group I, Category EPL Ma Equipment Intended to Remain Functional in

Atmospheres Endangered by Firedamp and/or Coal Dust;

--- Part 24.Equipment Protection by Special Protection "s";

--- Part 25.Requirements for Process Sealing between Flammable Process Fluids

and Electrical Systems;

--- Part 26.Electrostatic Hazards - Guidance;

--- Part 27.Electrostatic Hazards - Test;

--- Part 28.Non-Electrical Equipment for Explosive Atmospheres - Basic Method

and Requirements;

--- Part 29.Non-Electrical Equipment for Explosive Atmospheres - Constructional

Safety "c", Control of Ignition Source "b", Liquid Immersion "k";

--- Part 30.Equipment and Components in Explosive Atmospheres in Underground

Mines;

--- Part 31.Equipment Dust Ignition Protection by Enclosure "t";

--- Part 32.Intrinsically Safe Systems with Electronically Controlled Spark Duration

Limitation;

--- Part 33.Equipment in Adverse Service Conditions;

--- Part 34.Equipment Assemblies;

--- Part 35.Classification of Areas for Explosive Dust Atmospheres.

This Document replaced GB 3836.4-2010 Explosive Atmospheres - Part 4.Equipment

Protection by Intrinsic Safety "i", GB 3836.19-2010 Explosive Atmospheres - Part 19.

Fieldbus Intrinsically Safe Concept (FISCO), and GB 12476.4-2010 Electrical

Apparatus for Use in the Presence of Combustible Dust - Part 4.Protection by Intrinsic

Safety "iD". Mainly based on GB 3836.4-2010, this Document integrated the major

contents of GB 3836.19-2010 and GB 12476.4-2010.Compared with GB 3836.4-2010,

this Documents had the major technical changes as follows besides the structural

adjustments and editorial modifications.

--- Integrate the requirements of equipment for combustible dust environment in GB

12476.4-2010;

--- Integrate the requirements of FISCO equipment in GB 3836.19-2010 (see Annex

Explosive Atmospheres - Part 4.

Equipment Protection by Intrinsic Safety "i"

1 Scope

This document specifies the construction and testing of intrinsically safe apparatus

intended for use in an explosive atmosphere and for associated apparatus, which is

intended for connection to intrinsically safe circuits which enter such atmospheres.

This type of protection is applicable to electrical equipment in which the electrical

circuits themselves are incapable of causing an explosion in the surrounding explosive

atmospheres.

2 Normative References

The provisions in following documents become the provisions of this Document

through reference in this Document. For the dated documents, only the versions with

the dates indicated are applicable to this Document; for the undated documents, only

the latest version (including all the amendments) is applicable to this Document.

GB/T 3836.1-2021 Explosive atmospheres - Part 1.Equipment - General

requirements (IEC 60079-0.2017, MOD)

GB/T 3836.3 Explosive Atmospheres - Part 3.Equipment Protection by Increased

Safety "e" (GB/T 3836.3-2021, IEC 60079-7.2015, MOD)

GB/T 3836.18 Explosive atmospheres - Part 18.Intrinsically safe electrical

systems (GB/T 3836.18-2017, IEC 60079-25.2010, MOD)

GB/T 4207 Method for the determination of the proof and the comparative tracking

indices of solid insulating materials (GB/T 4207-2012, IEC 60112.2009, IDT)

GB/T 4208 Degrees of Protection Provided by Enclosure (IP Code) (GB/T 4208-

2017, IEC 60529.2013, IDT)

GB/T 6109.2 Enamelled round winding wire - Part 2.Polyester enamelled round

copper wire class 155 (GB/T 6109.2-2008, IEC 60317-3.2004, IDT)

GB/T 6109.5 Enamelled round winding wire - Part 5.Polyesterimide enamelled

round copper wire class 180 (GB/T 6109.5-2008, IEC 60317-8.1997, IDT)

GB/T 6109.6 Enamelled round winding wire - Part 6.Polyimide enamelled round

copper wire class 220 (GB/T 6109.6-2008, IEC 60317-7.1997, IDT)

GB/T 6109.20 Enamelled round winding wire - Part 20.Polyester on

polyesterimide overcoated with polyamide-imide enamelled round copper wire

class 200 (GB/T 6109.20-2008, IEC 60317-13.1997, IDT)

GB/T 7957 General Requirements for Construction, Performance and Explosion

Protected Testing of Caplights for Use in Mines Susceptible to Firedamp (GB/T

7957-2017, IEC 60079-35-1.2011, IEC 60079-35-2.2011, NEQ)

GB/T 9364 (all parts) Miniature fuses [IEC 60127 (all parts)]

GB/T 11021 Electrical insulation -Thermal evaluation and designation (GB/T

11021-2014, IEC 60085.2007, IDT)

GB/T 16657.2 Industrial communication networks - Fieldbus specifications - Part

2 Physical layer specification and service definition (GB/T 16657.2-2008, IEC

61158-2.2007, IDT)

GB/T 16935.1 Insulation Coordination for Equipment within Low-Voltage Systems

- Part 1.Principles Requirements and Tests (GB/T 16935.1-2008, IEC 60664-

1.2007, IDT)

GB/T 16935.3 Insulation coordination for equipment within low-voltage systems -

Part 3.Use of coating, potting or moulding for protection against pollution (GB/T

16935.3-2016, IEC 60664-3.2010, IDT)

ANSI/UL 248-1 Low-voltage fuses - Part 1.General requirements

3 Terms and Definitions

For the purposes of this Document, the terms and definitions given in GB/T 3836.1-

2021 and the following apply.

4 Grouping and Classification of Intrinsically Safe

Apparatus and Associated Apparatus

Intrinsically safe and associated apparatus which has a type of protection listed in GB/T

3836.1-2021 for use in the appropriate explosive atmosphere, shall be grouped in

accordance with equipment grouping requirements of GB/T 3836.1-2021 and shall

have a maximum surface temperature or temperature class assigned in accordance

with the temperature requirements of GB/T 3836.1-2021

Associated apparatus which has no such type of protection listed in GB/T 3836.1-2021

shall only be grouped in accordance with the equipment grouping requirements of

GB/T 3836.1-2021.

5 Levels of Protection and Ignition Compliance

Requirements of Electrical Apparatus

6 Apparatus Construction

NOTE. The requirements given in this clause apply, unless otherwise stated in the relevant

subclauses, only to those features of intrinsically safe apparatus and associated apparatus

which contribute to this type of protection.

For example, the requirements for encapsulation with casting compound apply only if

encapsulating is required to satisfy 6.3.5 or 6.6.

7 Components on which Intrinsic Safety Depends