1 Scope
This part of GB/T 16935.1 applies to assemblies protected against pollution by the use of
coating, potting or moulding, thus allowing a reduction of clearance and creepage distances as described in Part 1 or Part 5.
Note 1: When reference is made to Part 1 or Part 5, GB/T 16935.1-2008 or GB/T 16935.5-2008 are meant.
This standard describes the requirements and test procedures for two methods of protection:
— type 1 protection improves the microenvironment of the parts under the protection;
— type 2 protection is considered to be similar to solid insulation.
This standard also applies to all kinds of protected printed boards, including the surface of inner layers of multi-layer boards, substrates and similarly protected assemblies. In the case of multi-layer printed boards, the distances through an inner layer are covered by the
requirements for solid insulation in Part 1.
Note 2: Examples of substrates are hybrid integrated circuits and thick-film technology.
This standard refers only to permanent protection. It does not cover assemblies that are subjected to mechanical adjustment or repair.
The principles of this standard are applicable to functional, basic, supplementary and reinforced insulation.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2423.1-2008 Environmental Testing for Electric and Electronic Products — Part 2: Test methods — Tests A: Cold (IEC 60068-2-1:2007, IDT)
GB/T 2423.2-2008 Environmental Testing for Electric and Electronic Products — Part 2: Test Methods — Tests B: Dry Heat (IEC 60068-2-2:2007, IDT)
GB/T 2423.3-2006 Environmental Testing for Electric and Electronic Products — Part 2: Testing Methods — Test Cab: Damp Heat Steady State (IEC 60068-2-78:2001, IDT)
GB/T 2423.22-2012 Environmental Testing for Electric and Electronic Products — Part 2: Test Methods Test N: Change of Temperature (IEC 60068-2-14:2009, IDT)
GB/T 16935.1-2008 Insulation Coordination for Equipment within Low-voltage Systems — Part 1: Principles, Requirements and Tests (IEC 60664-1:2007, IDT)
GB/T 16935.5-2008 Insulation Coordination for Equipment within Low-voltage Systems — Part 5: Comprehensive Method for Determining Clearances and Creepage Distances Equal to or Less Than 2mm (IEC 60664-5:2007, IDT)
IEC 60326-2:1990 Printed Boards — Part 2: Test Methods)
Foreword II
Introduction IV
1 Scope
2 Normative References
3 Definitions
4 Design Requirements
5 Tests
Annex A (Normative) Test Sequence
Annex B (Normative) Technical Committees' Decisions
Annex C (Normative) Printed Wiring Board for Testing Coatings
Bibliography
