GB 12476.4-2010 English PDF (GB12476.4-2010)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB 12476.4-2010
Historical versions: GB 12476.4-2010
Preview True-PDF (Reload/Scroll if blank)

GB 12476.4-2010: Electrical apparatus for use in the presence of combustible dust -- Part 4: Protection by intrinsic safety iD
GB 12476.4-2010
Electrical apparatus for use in the presence of combustible dust.Part 4. Protection by intrinsic safety iD
ICS 29.260.20
K35
National Standards of People's Republic of China
Combustible dust Electrical Equipment
Part 4. Intrinsic safety "iD"
Part 4. Protectionbyintrinsicsafety "iD"
(IEC 61241-11.2005, IDT)
Issued on. 2010-08-09
2011-08-01 implementation
Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
Standardization Administration of China released
Table of Contents
Introduction Ⅲ
Introduction Ⅳ
1 Scope 1
2 Normative references 3
3 Terms and definitions 3
4 Grouping and classification of intrinsically safe apparatus and associated equipment 3
Level 5 electrical equipment 3
6 equipment Structure 3
7 elements with intrinsic safety-related 4
8 reliable components, reliable components and reliable connection 5
Barrier diode 9 5
10 type test 5
11 routine inspection and test 6
12 6 Flag
13 Document 7
Appendix A (normative) 8
Annex B (informative) 8
Annex C (normative) 8
Table 1 IEC 61241-0.2004 applies specific provisions 1
Table 2 allows the power dissipation member 4
Foreword
All technical content in this section is mandatory.
GB 12476 "combustible dust electrical equipment" is divided into several parts.
--- Part 1. General requirements
--- Part 2. Selection and installation
--- Part 3. combustible dusts exist or may exist Classification of hazardous areas
--- Part 4. Intrinsic safety "iD"
--- Part 5. Housing protection type "tD"
--- Part 6. protective encapsulation "mD"
--- Part 7. protective positive pressure "pD"
--- Part 8. Test methods for determining the minimum ignition temperature of a dust
--- Part 9. Test method for determination of the dust layer resistivity
--- Part 10. Test methods for dust and air mixture Determination of minimum ignition energy
Part of this section is GB 412 476, the equivalent to using IEC 61241-11.2005 "combustible dust Electrical apparatus
Part 11. Intrinsic safety "iD" "(2005 English edition).
This part of IEC 61241-11.2005 was the following editorial changes.
--- Remove the IEC 61241-11.2005 Foreword;
--- Increase the national standard foreword.
This section of the Appendices A and C are normative appendix, Appendix B is an informative annex.
This part is proposed by the China Electrical Equipment Industrial Association.
This part of the National explosion-proof electrical equipment Standardization Technical Committee (SAC/TC9) focal point and is responsible for interpretation.
This part mainly drafted by. Nanyang Explosion Electric Institute, Shanghai Institute of Industrial Automation Instrumentation.
This part of the main participants. National explosion-proof electrical products for Quality Supervision and Inspection Center, Shenzhen Tean Electronics Co., Ltd. Huarong Group has
Ltd., Fushun Branch Coal Research Institute, blast Electric Co., Ltd.
The main drafters of this section. Xu Jianping, Zhang Gang, Fu Shuling, Wang Ping, Liu Heng Yun, Li River.
introduction
Many of dust generated in the production, processing, transportation and storage are flammable. If dust is mixed with air into proper proportion, when the point
When burning dust can quickly burn a tremendous explosion pressure. May appear in place of such combustible material usually requires the use of
Explosion-proof electrical equipment, it is necessary to take appropriate precautions to ensure that all such electrical equipment adequately protected to reduce ignition
The possibility of an external explosive atmosphere. Electrical apparatus, potential ignition sources include arcs and sparks, hot surfaces and friction sparks.
Spaces appear in the air dangerous quantities of dust, fibers and Fei Xu is divided into a dangerous place, and is divided according to the level of danger
Three hazardous areas.
Under normal circumstances, one of two methods to ensure the electrical safety of electrical equipment, namely. a method (whenever practicable) should
Electrical equipment installed in hazardous locations, the alternative approach to design, installation and maintenance of electrical equipment in accordance with the method recommended by the use of premises.
Electrical equipment could ignite combustible dust by following several main ways.
--- Electrical equipment related to the surface temperature is higher than the minimum ignition temperature of the dust. Dust ignition temperature and dust properties, the presence of dust-like
State, the thickness of the layers of dust and heat of the geometric shape.
--- Electrical components (such as switches, contacts, rectifiers, brushes and the like) of arcs or sparks.
--- Accumulation of electrostatic charge and discharge.
--- Radiant energy (electromagnetic radiation).
--- Mechanical and electrical equipment related to sparks, friction sparks or friction heat.
In order to avoid ignition hazards should do the following.
--- May accumulate dust or electrical equipment may come into contact with the surface temperature of the dust cloud shall be kept at the temperature limit specified in this section
the following;
--- Any spark or component temperature above the temperature limit specified in GB 12476.2 member shall.
● placed in a sufficient to prevent dust entering the enclosure, or
● limiting circuit to avoid energy capable of igniting combustible dust arcs, sparks or temperature;
--- Avoid any other ignition source.
Hazardous areas explosion-proof electrical equipment using several techniques. This section describes the technical characteristics of the type of protection of the safety provisions of the Mining
Take requirement. To ensure the safe use of electrical equipment in hazardous locations, comply with standard procedures of selection and installation of the most important.
If electrical equipment is running at its rated conditions, and be installed and maintained in accordance with the Code or regulations (such as prevention of over-current, internal
Short circuit and other circuit fault), for compliance with the requirements of this section GB 12476 includes only the required level of security. In particular, the internal or
Duration and severity of the external fault is limited to the electrical equipment can withstand without damage to the range is the most important, for example, should meet
IEC 60079-25 principle of co-design, and in accordance with GB 12476.2 requirements for installation.
We must comply with the following principles.
--- GB 3836.4 circuitry must meet the requirements in respect ⅡB category, in order to avoid the risk of spark ignition.
--- Requires IP6X or encapsulation technology in order to avoid the use of dust affect clearances and creepage distances. Thus, for housing or encapsulated to
That its overall integrity and importance of durability is much higher than the requirements of GB 3836.4.
--- Components (such as non-insulated probe) electrical equipment or electrical equipment without a crust or without encapsulation protection should be limited in order to avoid to protect
Since the energy dissipated directly into the accumulation of dust layer (by matching the energy conductive dust) caused by ignition, or parts table
Hot surface ignition.
--- For more than limit the power limit for all devices or equipment parts, in accordance with IEC 61241-0 limits its exposed surface
temperature. Surface may be a surface or encapsulated in the surface of the housing.
Combustible dust Electrical Equipment
Part 4. Intrinsic safety "iD"