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GB/T 16935.3-2016 English PDF (GBT16935.3-2016)

GB/T 16935.3-2016 English PDF (GBT16935.3-2016)

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GB/T 16935.3-2016: 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
Insulation coordination for equipment within low-voltage systems - Part 3. Use of coating, potting or molding for protection against pollution ICS 29.120
National Standards of People's Republic of China
Replacing GB/T 16935.3-2005
Low voltage system equipment with the insulation
Part 3. Use of coatings, cans and closures
Molded anti-fouling protection
Part 3. Useofcoating, pottingormouldingforprotectionagainstpolution
(IEC 60664-3..2010, IDT)
Posted on.2016-04-25
2016-11-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China China National Standardization Administration released
Preface Ⅰ
Introduction Ⅱ
1 range 1
2 Normative references 1
3 Definition 2
4 design requirements 3
5 Test 4
Appendix A (Normative) Test Procedure 10
Appendix B (normative) to determine the relevant product standards 11
Appendix C (Normative) Printed wiring board for coating test
References 15
GB/T 16935 "Insulation coordination of low voltage system equipment" is expected to be divided into the following sections. --- Part 1. Principles, requirements and tests;
--- Part 2-1. Application Guidance GB/T 16935 series of application, size examples and dielectric test; --- Part 2-2. Interface considerations - Application Note;
--- Part 3. The use of coating, sealing and molding anti-fouling protection; --- Part 4. high-frequency voltage stress considerations;
--- Part 5. Determination of clearances and creepage distances not exceeding 2mm. This section GB/T 16935 Part 3.
This section drafted in accordance with GB/T 1.1-2009 given rules.
This Part replaces GB/T 16935.3-2005 "Insulation coordination of equipment within low-voltage systems Part 3. The use of coating, sealing and molding Anti-fouling protection ", compared with GB/T 16935.3-2005 this section, the main technical differences are as follows. --- 4.4 "Size Determination Program" clearly type 2 protection of the minimum spacing of the provisions of the same applies to functional insulation; --- 5.5 "Scratch Resistance Test", modify the first paragraph and add a note, the scratch test for the specific parts of the more accurate Exact description
--- 5.6 "Visual inspection", 5.8.3 "Insulation resistance between conductors", 5.8.4 "AC withstand voltage test", 5.9.1 "Resistance to solder heat", 5.9.2 "Flammability" and reference standard in Appendix A IEC 60326-2 "Printed Board Part 2. Test Method" is replaced by IEC 61189-3 "Test methods for electrical materials, printed boards and other interconnecting structures and assemblies - Part 3. Interconnection structures (PCB) test method "to update the test basis and method;
--- 5.9.3 "Solubility" and Appendix A, the anti-soluble requirements "according to IEC 60326-2 in 8.5, using methylene chloride" to "use User and supplier to determine the organic solvent. "
This section uses the translation method is equivalent to using IEC 60664-3..2010 (Version 2.1) "Low-voltage system equipment with insulation Part 3 Points. the use of coating, sealing and molding anti-fouling protection. " This section should be GB/T 16935.1-2008 "Low-voltage system equipment insulation Part 1. Principles, Requirements and Tests "(IEC 60664-1..2007, IDT).
The documents of our country that are in conformity with the corresponding international documents that are normative references in this part are as follows. --- GB/T 4677-2002 Printed circuit board test method (eqvIEC 60326-2..1990). This section made the following editorial changes.
--- and 5.8.1 in the "93" suspected wrong, change it to "93% ± 3%." This part is proposed by China Electrical Equipment Industry Association. This part of the National Low Voltage Equipment Insulation Coordination Technical Committee (SAC/TC417) centralized. This section is responsible for drafting unit. Shanghai Electric Apparatus Research Institute. Participated in the drafting of this section. Delixi Electric Co., Ltd., Changshu Switch Manufacturing Co., Ltd. (formerly Changshu Switch Factory). The main drafters of this section. Huang Jingye, leather, Wu Qingyun, Zhang Lili, Lin Chuan, Zhou Jianxing. This part of the standard replaces the previous editions are.
--- GB/T 16935.3-2005.
This section GB/T 16935 specifies the conditions for rigid components (such as printed circuit boards and component terminals), the article Under the components, the clearances and creepage distances of the components can be reduced. It can be done in any type of package, such as coating, potting or molding Anti-fouling protection. This protection can be applied on one or both sides of the assembly. This section provides the insulation properties of protective materials. Between any two unprotected conductive parts, GB/T 16935.1-2008 and GB/T 16935.5-2008 in the electrical room The requirements for clearance and creepage distances apply.
This section relates only to permanent protection does not apply to the repaired components. Relevant product standards need to consider the impact on superheat conductors and component protection, especially under fault conditions, and determine if Necessary to add additional requirements.
For protection system applications, the safety of a component depends on a precise and controlled manufacturing process. Quality control requirements, for example Such as sampling test, should be considered in the product standards.
Low voltage system equipment with the insulation
Part 3. Use of coatings, cans and closures
Molded anti-fouling protection
1 Scope
GB/T 16935 This section applies to the use of coating, can sealing and molding anti-fouling protection components, such components clearance and Creepage distances may be less than the clearances and creepage distances specified in Part 1 or Part 5. Note 1. Part 1 refers to GB/T 16935.1-2008, Part 5 refers to GB/T 16935.5-2008. This section provides two types of protection requirements and test procedures. --- Type 1 protection for improving the micro-environment of the components to be protected; --- Type 2 protection similar to solid insulation.
This section also applies to all types of protected printed circuit boards, including multilayer printed circuit board inner surface of the substrate and similar protected group Pieces. For multilayer printed boards, the requirements for the distance through an inner layer are included in the solid insulation requirements of Part 1. Note 2. For example, the substrate can be made of hybrid integrated circuits and thick film technology. This section relates only to permanent protection does not apply to the mechanical adjustment and repair of components. The principle of this section applies to functional insulation, basic insulation, additional insulation and reinforced insulation. 2 Normative references
The following documents for the application of this document is essential. For dated references, only the dated version applies to this article Pieces. For undated references, the latest edition (including all amendments) applies to this document. GB/T 2423.1-2008 Environmental testing for electric and electronic products Part 2. Test methods Test A. Low temperature (IEC 60068-2-1. 2007, IDT)
GB/T 2423.2-2008 Environmental testing for electric and electronic products Part 2. Test methods Test B. High temperature (IEC 60068-2-2. 2007, IDT)
GB/T 2423.3-2006 Environmental testing for electric and electronic products Part 2. Test methods Test Cab. constant hot and humid test (IEC 60068-2-78..2001, IDT)
GB/T 2423.22-2012 Environmental testing for electric and electronic products Part 2. Test methods Test N. Temperature change (IEC 60068-2-14..2009, IDT)
Insulation coordination of equipment in low-voltage systems - Part 1. Principles, requirements and tests (IEC 60664-1. 2007, IDT)
GB/T 16935.5-2008 Insulation coordination of equipment in low-voltage systems - Part 5. Clearances and creepage up to 2 mm How to determine the distance (IEC 60664-5..2007, IDT)
IEC 60326-2..1990 Printed boards - Part 2. Test methods (Printedboards-Part 2. Testmethods) IEC 60454-3-1..1998 Electrical pressure-sensitive adhesive tapes Part 3. Specifications for individual materials Part 1. Pressure-sensitive adhesives with poly Pressure-sensitive adhesive tapes of electricalpurposes-Part 3. Specifications forindividualmaterials-Sheet1. PVCfilmtapeswithpressure-sensitiveadhesive) Amendment 1 (2001)
IEC 61189-2..2006 Test Methods for Electrical Materials, Printed Boards and Other Interconnecting Structures and Components - Part 2. Interconnection Structures Test methods for materials (printed matter and conductive interconnects truc- turesandassemblies-Part 2. Testmethodsformaterialsforinterconnectionstructures) IEC 61189-3..2007 Test methods for electrical material, printed boards and other interconnecting structures and assemblies - Part 3. Interconnection structures (PCB) test method [Testmethodsforelectrmaterials, printedboardsandotherinterconnection structuresandassemblies-Part 3. Testmethodsforinterconnectionstructures (printedboards)] IEC 61249-2 (All Parts) Materials for PCBs and Other Interconnects. Cladding and Non-Cladding Reinforced Base Materials forprintedboardsandotherinterconnectingstructures-Reinforcedbasematerials, cladandunclad) IEC Guide 104..2004 Development of Safety Publications and Applications of Essential Safety Publications and Complete Safety Publications (Theprep- arationofsafetypublicationsandtheuseofbasicsafetypublicationsandgroupsafetypublications) 3 definition
In addition to the definition of GB/T 16935.1-2008, the following definitions are added. 3.1
An insulating material on which conductive patterns can be formed.
Note. The substrate can be rigid or flexible, or rigid-flexible. It can be a non-conductive medium or an insulatingly treated metal plate. [IEC 60194..2006, Definition 40.1334]
Printed circuit board
Common name for fully processed printed circuit and printed circuit structure. Note. Printed boards include single-sided, double-sided, and multilayer boards with a rigid, flexible, and rigid hybrid substrate. [IEC 60194..2006, definition 60.1485]
Conductor conductor
A single conductive path in a conductive pattern.
[IEC 60194..2006, Definition 22.0251]
Any way that can reduce the environmental impact.
Coating coating
Eg varnish or dry film insulation on the surface of the component.
Note. Substrates for coatings and boards form an insulation system with similar solid insulation properties. 3.6
Solid insulation solidinsulation
Solid insulating material inserted between two conductive parts.
Note. Solid insulation contains the board itself and the coating when the board is coated. In other cases, solid insulation refers to the sealing material. 3.7
Clearances, Creepage distances, and any combination of insulation distances through insulation. 4 design requirements
4.1 principle
The size of the spacing between the conductors depends on the type of protection. When the protection type is type 1, the clearances and creepage distances shall be in accordance with the requirements of Part 1 or Part 5. If you meet this Part of the requirements, in this type of protection, pollution level 1. When the protection type is type 2, the spacing of the conductive parts shall meet the relevant requirements and tests of solid insulation in Part 1, and the distance between them shall be large Small shall not be less than the minimum clearance in a uniform electric field as specified in Part 1 or Part 5. 4.2 The scope of application of the environment
Design requirements apply to all microenvironments.
When choosing a protective material, consider, for example, temperature stress, chemical stress, mechanical stress or the stress listed in of Part 1. The moisture absorption of the protective material should not destroy the insulation properties of the protected part. Note. The absorption of humidity can be inspected by measuring the insulation resistance under wet conditions. 4.3 protection type requirements
Achieve protection through.
--- 1 type of protection to improve the protected part of the micro-environment. Under this type of protection, Part 1 or Part 5 to Level 1 Pollution degree clearances and creepage distances apply. Between two conductive parts, one or two conductive parts are required The pieces, including the full spacing between them, are under the protection of this type. --- 2 type of protection is similar to solid insulation. Under this type of protection, the requirements for solid insulation in Part 1 apply, and the spacing Should not be less than the value specified in Table 1. The requirements for clearances and creepage distances in Part 1 or Part 5 do not apply. in Between two conductive parts, one or two conductive parts are required, including the full spacing between them, in this type of protection So that there should be no air gap between the conductive parts, the protective material and the printed board. The requirements for clearances and creepage distances in Part 1 or Part 5 apply to other unprotected parts of the assembly. 4.4 size determination process
For Type 1 protection, the requirements for determining dimensions in Parts 5.1 and 5.2 or Part 5 of Part 1 apply. For type 2 protection, the spacing between the conductors to be protected shall not be less than the values specified in Table 1. These values apply to basic insulation, add extra Edge and strengthen the insulation. These values can also be applied to functional insulation. Note. For multilayer boards, the size of the inter-conductor spacing on the inner surface is dimensioned according to type 1 or type 2, depending on the protection test result.
Table 1 2 type of protection of the minimum spacing
The maximum voltage Upa
Minimum spacing
Up≤0.33 0.01
0.33 \u003cUp≤0.4 0.02
0.4 \u003cUp≤0.5 0.04
0.5 \u003cUp≤0.6 0.06
Table 1 (continued)
The maximum voltage Upa
Minimum spacing
0.6 \u003cUp≤0.8 0.1
0.8 \u003cUp≤1.0 0.15
1.0 \u003cUp≤1.2 0.2
1.2 \u003cUp≤1.5 0.3
1.5 \u003cUp≤2.0 0.45
2.0 \u003cUp≤2.5 0.6
2.5 \u003cUp≤3.0 0.8
3.0 \u003cUp≤4.0 1.2
4.0 \u003cUp≤5.0 1.5
5.0 \u003cUp≤6.0 2
6.0 \u003cUp≤8.0 3
8.0 \u003cUp≤10 3.5
10 \u003cUp≤12 4.5
12 \u003cUp≤15 5.5
15 \u003cUp≤20 8
20 \u003cUp≤25 10
25 \u003cUp≤30 12.5
30 \u003cUp≤40 17
40 \u003cUp≤50 22
50 \u003cUp≤60 27
60 \u003cUp≤80 35
80 \u003cUp≤100 45
a Since transient overvoltages have little effect on the protected components, they can be ignored. Measure the spacing before component protection.
5 test
5.1 General requirements
Protection is reasonable, after 5.7 pretreatment, with the 5.8 test to verify. Note. The suitability of the protection was evaluated after the scratch resistance test in 5.5, the visual inspection in 5.6 and the sample pretreatment in 5.7. Unless otherwise specified, six samples shall be used for the test. In addition, each related product standard may stipulate 5.9 additional tests, of which each test All on a separate new sample.
These tests are used for type tests. Each of the relevant product standards may consider other tests for use in routine tests or sampling tests Claim.
Test procedures in Appendix A.
No samples are allowed to fail during the test.
Appendix B lists other related product standards reference this section should determine the parameters. 5.2 Coating test samples
The test sample can be.
--- Accordance with the provisions of Appendix C, suitable for printed circuit board standard test sample; the sample used for testing should be the same with the product Small spacing;
--- Any PCB, as long as the test sample is representative of the product. 5.3 Molding and canning test samples
A representative sample of the product or product should be used.
5.4 Preparation of test samples
Printed boards should be cleaned and coated according to the manufacturer's normal procedures. Perform the welding procedure without components. Molded and potted No additional preparation is required for sample testing.
5.5 Scratch resistance test
Note. In some cases, it is not possible to perform scratch resistance tests on components that have been protected against potting by potting or molding, in which case the necessary replacement Substitution test or additional test.
Scratch test shall be carried out on the gap between the five pairs of conductive parts and conductive parts, and the test part shall be insulated at the maximum power between conductors Field strength of the place.
Scratch the protective layer with a rigid steel probe. The tip of the probe should be a conical shape with a 40 ° angle and the tip is rounded and should be ground Light, a radius of 0.25mm ± 0.02mm. The probe should be placed so that the force in the axial direction of the probe is 10N ± 0.5N. The probe is vertical The sample is scratched at a speed of about 20 mm/s in the direction of the flat surface of the edge of the protective conductor as shown in FIG. 1. Sample up to Less scratches 5 mm apart and at least 5 mm off the edge.
Note. The probe is located in the ABCD plate perpendicular to the sample. Figure 1 scratch resistance of the protective layer test
5.6 Visual inspection
Samples shall be visually inspected in accordance with Test 3V02 of IEC 61189-3..2007, 6.2. Sample should not appear.
--- blister
--- Expansion
--- Off from the substrate;
--- Pores
--- Adjacent to uncoated conductive part of the area, except the land;
--- Electromigration.
5.7 Test sample pretreatment
Pretreatment for most use occasions. For special occasions, you can consider modifying the parameters of the pretreatment, the specific changes By the relevant product standards.
Note. The weather conditions of 5.7.1 ~ 5.7.4 are used to simulate the aging. 5.7.1 Low temperature
Low temperature pretreatment (simulated storage and transport conditions) was performed according to test Ab of GB/T 2423.1-2008. Harsh degree by the relevant Product standards, and from the following conditions.
-10 ℃;
-25 ℃;
-40 ℃;
-65 ° C.
The test period is 96h.
5.7.2 Dry heat
Dry heat pretreatment according to GB/T 2423.2-2008 Test Bb. But with the printed board material and work surface temperature corresponding to the pre- The treatment time and pretreatment temperature are shown in Table 2.
Table 2 dry heat pretreatment
Maximum working surface temperature
Pretreatment temperature
Pretreatment time
Epoxy/cellulose paper
Epoxy/glass cloth surface/fiber
Vinyl paper core
Epoxy/glass cloth
Surface/non-woven glass core
Epoxy/glass cloth
Polyester/glass mat
Phenolic/cellulose paper (with defined
Flammability - vertical burning test) a
Phenolic/cellulose paper
a For a defined flammability reference is made to IEC 61189-2..2006 8.6 and IEC 61249 part 2. 5.7.3 rapid temperature changes
Rapid temperature changes Pretreatment according to the test Na in GB/T 2423.22-2012. The temperature is determined according to Table 3, severity level By the relevant product standards.
Table 3 harsh temperature rapid changes in the level
Harsh level

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