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This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization—Part 1: Structure and drafting of standards.
This standard replaces DL/T 376-2010 General technical requirements of silicone rubber insulation materials for composite insulators. The following main changes have been made with respect to DL/T 376-2010:
——The application scope of the former standard has been expanded from composite insulators and silicone rubber materials to polymeric insulators and polymer insulation materials respectively;
——The definitions of "elastomer polymer insulation material" and "rigid polymer insulation material" have been added;
——The requirements of elastomer polymer insulation materials and rigid polymer insulation materials have been specified;
——The hydrophobic contact angle method and requirements have been deleted, and the HC classification method and requirements have been kept.
This standard was proposed by China Electricity Council.
This standard is under the jurisdiction of the Technical Committee on Insulator of Standardization Administration of Power Industry (DL/TC 16).
During the process of implementing this standard, the relevant comments and recommendations, whenever necessary, can be fed back to the Standardization Center of the China Electricity Council (No.1, 2nd Lane, Baiguang Road, Beijing, 100761, China).
Introduction
Polymer insulation materials referred to in this standard refer to materials with hydrophobicity migration characteristics, such as silicone rubber, etc. It shall be noted that such materials may suffer weakened or temporarily lost hydrophobicity under certain conditions.
The fluorosilicone rubber insulation materials referred to in this standard are suitable for such environment as high-humidity areas, coastal areas, algae-breeding areas. Rigid polymer insulation materials are suitable for conditions such as bird trouble, sand wind, icing and trampling.
General technical requirements of insulation materials for umbrella skirt and sheath of polymeric insulators
1 Scope
This standard specifies the technical requirements and test methods of polymer insulation materials with hydrophobicity migration characteristics (hereinafter referred to as insulation materials) for outdoor AC and DC polymeric insulators with nominal voltage greater than 1,000V (hereinafter referred to as polymeric insulators).
This standard is applicable to the insulation materials for umbrella skirts and sheaths of polymeric insulators, including elastomer insulation materials (such as high-temperature vulcanized silicone rubber, liquid silicone rubber, fluorosilicone rubber, etc.) and rigid insulation materials (such as cycloaliphatic epoxy resin, polyolefin, etc.).
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 normative document referred to applies.
GB/T 528 Rubber, vulcanized or thermoplastic—Determination of tensile stress-strain properties
GB/T 529 Rubber vulcanized or thermoplastic—Determination of tear strength (Trouser, angle and crescent test pieces)
GB/T 531.1 Rubber vulcanized or thermoplastic—Determination of indentation hardness—Part 1: Durometer method (Shore hardness)
GB/T 1034-2008 Plastics—Determination of water absorption
GB/T 1408.1 Insulating materials—Test methods for electric strength—Part 1: Tests at power frequencies
GB/T 1409 Recommended methods for the determination of the permittivity and dielectric dissipation factor of electrical insulating materials at power, audio and radio frequencies including metre wavelengths
GB/T 2411 Plastics and ebonite—Determination of indentation hardness by means of a durometer (Shore hardness)
GB/T 2567 Test methods for properties of resin casting body
GB/T 2900.5 Electrotechnical terminology—Insulating solids, liquids and gases
GB/T 2900.8 Electrotechnical terminology—Insulators
GB/T 2900.19 Electrotechnical terminology—High-voltage test technique and insulation co-ordination
GB/T 2941 Rubber—General procedures for preparing and conditioning test pieces for physical test methods
GB/T 3505-2009 Geometrical product specifications (GPS)—Surface texture: Profile method—Terms, definitions and surface texture parameters
GB/T 3960 Plastics—Test method for friction and wear by sliding
GB/T 4585 Artificial pollution tests on high-voltage insulators to be used on A.C. systems
GB/T 5169.16 Fire hazard testing for electric and electronic products—Part 16: Test flames—50W horizontal and vertical flame test methods
GB/T 6553 Electrical insulating materials used under severe ambient conditions—Test methods for evaluating resistance to tracking and erosion
GB/T 9881 Rubber—Vocabulary
GB/T 10707 Rubber—Determination of the burning behaviour
GB/T 16422.1 Plastics—Methods of the exposure to laboratory light sources—Part 1: General guidance
GB/T 16422.2-2014 Plastics—Methods of exposure to laboratory light sources—Part 2: Xenon-arc sources
GB/T 16422.3-2014 Plastics—Methods of exposure to laboratory light sources—Part 3: Fluorescent UV lamps
GB/T 19466.3 Plastics—Differential scanning calorimetry (DSC)—Part 3: Determination of temperature and enthalpy of melting and crystalliation
GB/T 21353 Test method for determining the resistance of paint film to algae
GB/T 31838.2 Solid insulating materials—Dielectric and resistive properties—Part 2: Resistive properties(DC methods)—Volume resistance and volume resistivity
GB/T 34937 Insulators for overhead lines—Composite suspension and tension insulators for d.c. systems with a nominal voltage greater than 1,500V— Definitions, test methods and acceptance criteria
DL/T 627 Room temperature vulcanized silicon rubber anti-pollution coating for insulators
DL/T 1474 Hydrophobicity measuring method of composite insulators for AC and DC overhead lines with a nominal voltage greater than 1,000V
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 9881, GB/T 2900.5, GB/T 2900.8 and GB/T 2900.19 as well as the following apply.
3.1
elastomer polymer insulation material
insulating polymeric material with obvious deformation under weak stress and rapid recovery to the original state and size after stress relaxation
3.2
rigid polymer insulation material
insulating polymeric material with rigid mechanical properties
3.3
polymeric insulator
insulator with insulating part made of at least one organic material
Note 1: Polymeric insulators may also be called non-ceramic insulators.
Note 2: Connectors may be installed at both ends of insulating part.
4 Technical requirements
4.1 Laboratory test environment
The laboratory environment specified in this standard is 20°C±5°C and 50% to 70%.
4.2 Basic performance
The hydrophobicity of insulation materials shall meet the requirements of DL/T 1474.
The basic performance of insulation materials shall meet the following requirements:
a) Initial classification of hydrophobicity: Generally they are HC1 to HC2, and HC3 test objects are not more than one.
b) Weakening characteristics of hydrophobicity: Generally they are HC3 to HC4, and HC5 test objects are not more than one after soaking for 96 h.
c) Recovery characteristics of hydrophobicity: Generally they are HC2 to HC3, and HC4 test objects shall not be more than one after soaking for 96 h and standing for 48 h.
d) Migration characteristics of hydrophobicity: Generally they are HC2 to HC3, and HC4 to HC5 test objects shall not be more than one after migration for 96 h.
e) The resistance to tracking and erosion shall not be inferior to Grade TMA4.5.
Note: Non-ionic wetting agent of isooctyl phenoxy polyethoxy ethanol is not added to the contaminated liquid used in polyolefin materials.
f) Breakdown field strength AC: ≥ 20 kV/mm.
The specimen is (1.0 ± 0.1) mm in thickness for elastomer insulation materials, (2.0 ± 0.2) mm in thickness for rigid insulation materials.
g) Hardness change test: The hardness value will not change for more than 10% after they are placed in boiling water for 42 h.
h) Accelerated weathering test: The insulation materials shall meet the requirements of ultraviolet radiation test. See Annex A for the test procedures and judgment criteria. It is an test item subject to negotiation.
i) Corrosion resistance: The coating shall be free from peeling, wrinkling, blistering or discoloration after being socked in acid, alkali or salt reagents (concentration of 3%) at 25°C for 24 h.
4.3 Elastomer polymer insulation materials
4.3.1 Basic requirements of silicone rubber insulation materials
In addition to the basic requirements of 4.2, silicone rubber insulation materials shall also meet the following requirements:
a) Tear strength (rectangularity): ≥ 10 kN/m;
b) Tensile strength (dumbbell shape): ≥ 4 MPa;
c) Elongation at break (dumbbell shape): ≥ 150%;
d) Flammability: Grade FV-0.
4.3.2 Fluorosilicone rubber insulation materials
4.3.2.1 Resistance of fluorosilicone rubber to algae: Grade 0.
4.3.2.2 Fluorosilicone rubber not only meets the requirements of silicone rubber insulation materials in this standard, but also meets the following requirements for hydrophobicity:
a) Initial classification of hydrophobicity: Generally they are HC1, and HC2 test objects shall not be more than one.
b) Weakening characteristics of hydrophobicity: Generally they are HC1 to HC2, and HC3 test objects are not more than one after soaking for 96 h.
c) Recovery characteristics of hydrophobicity: Generally they are HC2 to HC3, and HC4 test objects shall not be more than one after soaking for 192 h and standing for 48 h.
d) Migration characteristics of hydrophobicity: Generally they are HC1 to HC2, and HC3 test objects shall not be more than one after migration for 96 h.
e) Durability characteristics of hydrophobicity: Generally fluorosilicone rubber insulation materials are HC3 to HC4, and HC5 test objects shall not be more than one after soaking for 192 h.
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Terms and definitions
4 Technical requirements
5 Inspection rules
6 Test methods
Annex A (Normative) Accelerated weathering test
Annex B (Normative) Description of hydrophobicity classification and the typical conditions
