1 Scope
This part of GB/T 1981 specifies methods of test to be used for testing varnishes used for electrical insulation.
This includes methods of test to be applied before and others to be applied after drying and/or curing of the varnishes used for electrical insulation.
2 Normative references
The following normative documents contain provisions which, through reference in this part of GB/T 1981, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest editions apply to this part.
GB/T 1408.1-2006 Electrical strength of insulating materials - Test methods - Part 1: Tests at power frequencies (IEC 60243-1:1998, IDT)
GB/T 1409-2006 Recommended methods for the determination of the permittivity and dielectric dissipation factor of electrical insulating materials at power, audio and radio frequencies including meter wavelengths (IEC 60250:1969, MOD)
GB/T 1410-2006 Methods of test for volume resistivity and surface resistivity of solid electrical insulating materials (IEC 60093:1980, IDT)
GB/T 1981.1-2007 Varnishes used for electrical insulation - Part 1: Definitions and general requirements (IEC 60464-1:1998, IDT)
GB/T 2423.16-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Test J and guidance: Mold growth (IEC 60068-2-10:2005, IDT)
GB/T 2900.5-2002 Electrotechnical terminology - Electrical insulating solids, liquids and gases (eqv IEC 60050-212:1990)
GB/T 2918-1998 Plastics - Standard atmospheres for conditioning and testing (idt ISO 291:1997)
GB/T 4074.4-2008 Winding wires - Test methods - Part 4: Chemical properties (IEC 60851-4:2005, IDT)
GB/T 5208-2008 Determination of flash point - Rapid equilibrium closed cup method (ISO 3679:2004, IDT)
GB/T 6753.4-1998 Paints and varnishes - Determination of flow time by use of flow cups (eqv ISO 2431:1993)
GB/T 11026.1-2003 Electrical insulating materials – Properties of thermal endurance – Part 1: Ageing procedures and evaluation of test results (IEC 60216-1:2001, IDT)
GB/T 11026.2-2000 Guide for the determination of thermal endurance properties of electrical insulating materials - Part 2: Choice of test criteria (idt IEC 60216-2:1990)
GB/T 11026.3-2006 Electrical insulating materials - Thermal endurance properties - Part 3: Instructions for calculating thermal endurance characteristics (IEC 60216-3:2002, IDT)
GB/T 11026.4-1999 Guide for the determination of thermal endurance properties of electrical insulating materials - Part 4: Ageing ovens - Single-chamber ovens (IEC 60216-4-1:1990, IDT)
GB/T 11028-1999 Test methods for the determination of bond strength of impregnating agents to an enamelled wire substrate (eqv IEC 61033:1991)
GB/T 19264.3-2003 Specification for pressboard and presspaper for electrical purposes - Part 3: Specifications for individual materials - Sheet 1: Requirements for pressboard, types B.0.1, B.2.1, B.2.3, B.3.1, B.3.3, B.4.1, B.4.3, B.5.1, B.6.1 and B.7.1 (IEC 60641-3-1:1992, IDT)
ISO 558:1980 Conditioning and testing - Standard atmosphere - Definitions
ISO 760:1978 Determination of water - Karl Fischer method (General method)
ISO 1144:1973 Textiles - Universal system for designating linear density (Tex System)
ISO 1513:1992 Paints and varnishes - Examination and preparation of samples for testing
ISO 1514:1993 Paints and varnishes - Standard panels for testing
ISO 1519:1973 Paints and varnishes - Bend test (cylindrical mandrel)
ISO 1520:1999 Paints and varnishes - Cupping test
ISO 2078:1993 Textile glass - Yarns - Designation
ISO 2113:1996 Reinforcement fibres - Woven fabrics - Basis for a specification
ISO 2555:1989 Plastics - Resins in the liquid state or as emulsions or dispersions - Determination of apparent viscosity by the Brookfield Test method
ISO 2578:1993 Plastics - Determination of time-temperature limits after prolonged exposure to heat
ISO 2592:2000 Determination of flash and fire points - Cleveland open cup method
ISO 2808:1997 Paints and varnishes - Determination of film thickness
ISO 2811 Paints and varnishes - Determination of density
ISO 2812-1:1993 Paints and varnishes - Determination of resistance to liquids - Part 1: General methods
ISO 3219:1993 Plastics - Polymers/resins in the liquid state or as emulsions or dispersions - Determination of viscosity using a rotational viscometer with defined shear rate
ISO 3251:1993 Paints and varnishes - Determination of non-volatile matter of paints, varnishes and binders for paints and varnishes
ISO 11890-1:2000 Paints and varnishes - Determination of volatile organic compound (VOC) content - Part 1: Difference method
ISO 11890-2:2000 Paints and varnishes - Determination of volatile organic compound (VOC) content - Part 2: Gas-chromatographic method
ISO 15528:2000 Paints, varnishes and raw materials for paints and varnishes - Sampling
IEC 60296:2003 Fluids for electrotechnical applications - Unused mineral insulating oils for transformers and switchgear
IEC 61099:1992 Specifications for unused synthetic organic esters for electrical purposes
3 Definitions
For the purposes of this part of GB/T 1981, the following definitions as well as the definitions of GB/T 2900.5-2002 and GB/T 1981.1-2007 apply.
3.1
volume resistance
that part of the insulation resistance which is due to conduction through the volume and excludes surface current
3.2
volume resistivity
volume resistance reduced to a cubical unit volume
3.3
dielectric dissipation factor
tanδ
numerical value of the ratio of the imaginary to the real part of the complex permittivity
3.4
relative permittivity
εr
ratio of the absolute permittivity to the electric constant
Note: In practical engineering, it is usual to employ the term "permittivity" when referring to relative permittivity.
Foreword I
1 Scope
2 Normative references
3 Definitions
4 General notes on methods of test
5 Methods of test for undried and/or uncured varnishes
6 Methods of test for dried and/or cured varnishes
Annex A (Informative) Comparison between the clause/subclause numbers of this part and those of IEC 60464-2:2001
Annex B (Informative) Technical differences between this part and IEC 60464-2:2001 and their causes
