GB/T 42710.1-2023 Direct current (DC) plugs and socket-outlets for household and similar purposes - Part 1: General requirements
1 Scope
This document specifies the technical requirements for the classification, marking, protection against electric shock, structure, mechanical performance and electrical performance of plugs and socket-outlets for household and similar purposes.
This document applies to plugs and fixed or portable socket-outlets for DC only, with a rated voltage not exceeding 400V and a rated current not exceeding 32A, intended for household and similar purposes, either indoors or outdoors.
The rated current is limited to 16A maximum for DC socket-outlets provided with screwless terminals.
Plugs and socket-outlets within the scope of this document are applicable to circuits for which the following protections have been implemented:
—Basic protection;
—Overcurrent protection (based on that the maximum current of each socket-outlet does not exceed 16A);
—Fault protection (indirect contact protection); and
—Additional protection.
DC plugs and socket-outlets that comply with the requirements of this document are suitable for use at ambient temperatures generally not exceeding +40℃, but not exceeding +35℃ at average during a period of 24 hours, with a lower limit of -5℃ for ambient air temperature.
The ambient temperature around the installation location of socket-outlets that meet the requirements of this document and are built into or installed in the equipment must not exceed 35℃.
In locations where special conditions prevail, such as in ships, vehicles and the like and in hazardous locations, for example where explosions are liable to occur, special constructions may be required.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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 2099.1-2021 Plugs and socket-outlets for household and similar purposes - Part 1:General requirements
GB/T 2099.7-2015 Plugs and socket-outlets for household and similar purposes - Part 2-7: Particular requirements for cord extension sets
GB/T 2423.4 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle)
GB/T 2423.7 Environmental testing - Part 2: Test methods - Test Ec: Rough handling shocks, primarily for equipment-type specimens
GB/T 2423.55 Environmental testing for electric and electronic products - Part 2: Test methods - Test Eh: Hammer tests
GB/T 2900.70-2008 Electrotecnical terminology - Electrical accessories
GB/T 2900.71-2008 Electrotechnical terminology - Electrical installations
GB/T 2900.73-2008 Electrotechnical terminology - Earthing and protection against electric shock
GB/T 4207 Method for the determination of the proof and the comparative tracking indices of solid insulating materials
GB/T 4208 Degrees of protection provided by enclosure (IP code)
GB/T 5013 (All parts) Rubber insulated cables of rated voltages up to and including 450/750V
GB/T 5023 (All parts) Polyvinyl chloride insulated cables of rated voltages up to and including 450/750V
GB/T 5169.10 Fire hazard testing for electric and electronic products - Part 10: Glow/hot-wire based test methods - Glow-wire apparatus and common test procedure
GB/T 5169.11 Fire hazard testing for electric and electronic products - Part 11: Glowing/hot-wire based test methods - Glow-wire flammability test method for end-products (GWEPT)
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 5465.1-2009 Graphical symbols for use on electrical equipment - Part 1: Overview and classification
GB/T 5465.2 Graphical symbols for use on electrical equipment - Part 2: Graphical symbols
GB/T 9797 Metallic and other inorganic coatings - Electrodeposited coatings of nickel, nickel plus chromium, copper plus nickel and of copper plus nickel plus chromium
GB/T 9799 Metallic and other inorganic coatings - Electroplated coatings of zinc with supplementary treatments on iron or steel
GB/T 10963.2 Electrical accessories - Circuit-breakers for overcurrent protection for household and similar installations - Part 2:Circuit-breakers for AC and DC operation
GB/T 12599 Metallic coatings - Electroplated coatings of tin - Specification and test methods
GB/T 15092.1 Switches for appliances - Part 1: General requirements
GB/T 16842-2016 Protection of persons and equipment by enclosures - Probe for verification
GB/T 16915 (All parts) Switches for household and similar fixed electrical installations
GB/T 17194 Conduits for electrical purposes - Outside diameters of conduits for electrical installations and threads of conduits and fittings
GB/T 20002.4-2015 Drafting for special aspects in standards - Part 4: Safety aspects for their inclusion in standards
GB/Z 40825-2021 Electrical accessories - Harmonization of general rules
GB/T 42710.2-2023 Direct current (DC) plugs and socket-outlets for household and similar purposes - Part 2: Types and dimensions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
Note 1: Throughout this document the word "earthing" is used for "protective earthing" unless otherwise stated.
Note 2: The term "accessory" is used as a general term covering plugs and socket-outlets; the term "portable accessory" covers plugs and portable socket-outlets. Examples of the use of accessories are shown in Figure 1a).
Note 3: Throughout this document the term "socket-outlet" covers both fixed and portable socket-outlets, except where the reference is specific to one type or the other.
3.1
plug
accessory having pins designed to engage with the socket-contacts of a socket-outlet, intended for frequent use by an ordinary person, and equipped with components for electrical connection of flexible cables and mechanical positioning
Note 1: For special purposes such as lighting chains (see also GB 7000.9), two or three single-core cables can be connected within the plug.
Note 2: For "ordinary person", see 195-04-03 of GB/T 2900.73-2008.
3.2
socket-outlet
accessory having socket-contacts designed to engage with the pins of a plug, intended for frequent use by an ordinary person, and equipped with terminal or termination for cable connection
3.3
fixed socket-outlet
socket-outlet intended to be connected to fixed wiring
3.4
portable socket-outlet
socket-outlet intended to be connected to or integral with one flexible cable and which can easily be moved from one place to another while connected to the supply
3.5
multiple socket-outlet
combination of two or more socket-outlets
Note: An example is shown in Figure 1b).
3.6
socket-outlet for appliances
socket-outlet integral with or intended to be installed or secured to an electrical installation
3.7
rewirable plug or rewirable portable socket-outlet
accessory so constructed that the flexible cable can be replaced
3.8
non-rewirable plug or non-rewirable portable socket-outlet
accessory integrated with the flexible cable after connection and assembly by the manufacturer (see 14.1)
3.9
moulded-on accessory
non-rewirable portable accessory the manufacture of which is completed by insulating material moulded around pre-assembled component parts and the terminations for the flexible cable
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Tests
6 Ratings
7 Classification
8 Marking
9 Checking of dimensions
10 Protection against electric shock
11 Provision for earthing
12 Terminals and terminations
13 Construction of fixed socket-outlets
14 Construction of plugs and portable socket-outlets
15 Interlocked socket-outlets
16 Resistance to ageing, protection provided by enclosures, and resistance to humidity
17 Insulation resistance and electric strength
18 Operation of earthing contacts
19 Temperature rise
20 Breaking capacity
21 Normal operation
22 Force necessary to withdraw the plug
23 Flexible cables and their connection
24 Mechanical strength
25 Resistance to heat
26 Screws, current-carrying parts and connections
27 Creepage distances, clearances and distances through sealing compound
28 Resistance of insulating material to abnormal heat, to fire and to tracking
29 Resistance to rusting
30 Additional tests on pins provided with insulating sleeves
Annex A (Normative) List of specimens required for test
Annex B (Normative) Safety-related routine tests for factory-wired portable accessories (protection against electric shock and correct polarity)
Annex C (Informative) Alternative gripping tests
Annex D (Normative) Switches incorporated in portable socket-outlets
Annex E (Normative) Hot wire ignition (HWI) test and arc ignition (AI) test
Bibliography
Figure 1 Examples of accessories
Figure 2 Pillar terminals
Figure 3 Screw terminals and stud terminals
Figure 4 Saddle terminals
Figure 5 Mantle terminals
Figure 6 Thread-forming screw
Figure 7 Thread-cutting screw
Figure 8 Examples of membranes and grommets
Figure 9 Test procedures for normal operation (see Clause 21)
Figure 10 Test wall in accordance with the requirements of 16.2.3
Figure 11 Apparatus for compression test of 24.6
Figure 12 Test plug used for 10.3
Figure 13 Probe for checking non-accessibility of live parts inside shutters
Figure 14 Probe for checking non-accessibility of live parts inside shutters, and of live parts of socket-outlets with increased protection
Figure 15 Apparatus for checking damage to conductors
Figure 16 Schematic diagram for bending test
Figure 17 Appliance for checking the resistance to lateral strain
Figure 18 Appliance for testing pins which are not solid
Figure 19 Schematic diagram of the clamping unit for temperature rise test
Figure 20 Apparatus for breaking capacity and normal operation test
Figure 21 Circuit diagrams for breaking capacity and normal operation tests
Figure 22 Apparatus for verification of maximum withdrawal force
Figure 23 Gauge for the verification of minimum withdrawal force
Figure 24 Apparatus for testing flexible cable retention
Figure 25 Apparatus for bending test
Figure 26 Sketches showing the application of the impacts according to Table 21
Figure 27 Apparatus for impact test at low temperature of 24.5
Figure 28 Apparatus for abrasion test on insulating sleeves of plug pins
Figure 29 Apparatus for mechanical strength test on multiple portable socket-outlets
Figure 30 Test apparatus to verify the retention of pins in the plug
Figure 31 Apparatus for test on cover or cover-plates
Figure 32 Gauge (thickness about 2 mm) for the verification of the outline of covers or cover-plates
Figure 33 Examples of application of the gauge of Figure 32 on covers fixed without screws on a mounting surface or supporting surface
Figure 34 Examples of application of the gauge of Figure 32 in accordance with the requirements of 24.16
Figure 35 Gauge for verification of grooves, holes and reverse tapers
Figure 36 -Sketch showing the direction of application of the gauge of Figure 35
Figure 37 Apparatus for compression test for the verification of resistance to heat specification of 25.5
Figure 38 Ball pressure test apparatus
Figure 39 Diagrammatic representation of 28.1.1
Figure 40 Apparatus for testing resistance to abnormal heat of insulating sleeves of plug pins
Figure 41 Apparatus for pressure test at high temperature
Figure 42 Impact test apparatus on pins provided with insulating sleeves
Figure C.1 Reference plug for gripping test
Figure C.2 Example of the test equipment for plug gripping test
Figure E.1 Apparatus for hot wire ignition test
Figure E.2 Circuit diagram for arc ignition test
Table 1 Preferred combinations of ratings
Table 2 Relationship between rated current and connectable nominal cross-sectional areas of copper conductors
Table 3 Values for pull test for screw-type terminals
Table 4 Composition of conductors
Table 5 Tightening torques for the verification of the mechanical strength of screw-type terminals
Table 6 Relationship between rated current and connectable cross-sectional areas of copper conductors for screwless terminals
Table 7 Value for pull test for screwless terminals
Table 8 Values for flexing under mechanical load test for copper conductors
Table 9 Test current for the verification of electrical and thermal stresses in normal use for screwless terminals
Table 10 Nominal cross-sectional areas of rigid copper conductors for bending test of screwless terminals
Table 11 Bending test forces for screwless terminals
Table 12 Forces to be applied to covers, cover-plates or actuating members whose fixing is not dependent on screws
Table 13 External cable dimension limits for surface-type socket-outlets
Table 14 Test current and nominal cross-sectional areas of copper conductors for temperature rise test
Table 15 Maximum and minimum withdrawal force for socket-outlets
Table 16 External dimensions of flexible cables to be accommodated by cable anchorages
Table 17 Torque test values for cable anchorages
Table 18 Maximum dimensions of flexible cables to be accommodated in rewirable accessories
Table 19 Relationship between rating of accessories, nominal cross-sectional areas of test conductors and test currents for the tests of temperature rise (Clause 19) and normal operation (Clause21)
Table 20 Type and length of the flexible cable of the cord extension set and the nominal cross-sectional area of the conductor
Table 21 Height of fall for impact tests
Table 22 Torque test values for cable glands
Table 23 Resistance to heat of different types or parts of accessories
Table 24 Creepage distances and clearances
Table 25 Creepage distances, clearances, and distances through insulating sealing compound
Table B.1 Diagrammatic representation of routine tests to be applied to factory-wired portable accessories
Table E.1 HWI and AI characteristics for materials required to secure current-carrying parts
Table E.2 HWI and AI characteristics for materials outside the scope of Table E.1
GB/T 42710.1-2023 Direct current (DC) plugs and socket-outlets for household and similar purposes - Part 1: General requirements
1 Scope
This document specifies the technical requirements for the classification, marking, protection against electric shock, structure, mechanical performance and electrical performance of plugs and socket-outlets for household and similar purposes.
This document applies to plugs and fixed or portable socket-outlets for DC only, with a rated voltage not exceeding 400V and a rated current not exceeding 32A, intended for household and similar purposes, either indoors or outdoors.
The rated current is limited to 16A maximum for DC socket-outlets provided with screwless terminals.
Plugs and socket-outlets within the scope of this document are applicable to circuits for which the following protections have been implemented:
—Basic protection;
—Overcurrent protection (based on that the maximum current of each socket-outlet does not exceed 16A);
—Fault protection (indirect contact protection); and
—Additional protection.
DC plugs and socket-outlets that comply with the requirements of this document are suitable for use at ambient temperatures generally not exceeding +40℃, but not exceeding +35℃ at average during a period of 24 hours, with a lower limit of -5℃ for ambient air temperature.
The ambient temperature around the installation location of socket-outlets that meet the requirements of this document and are built into or installed in the equipment must not exceed 35℃.
In locations where special conditions prevail, such as in ships, vehicles and the like and in hazardous locations, for example where explosions are liable to occur, special constructions may be required.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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 2099.1-2021 Plugs and socket-outlets for household and similar purposes - Part 1:General requirements
GB/T 2099.7-2015 Plugs and socket-outlets for household and similar purposes - Part 2-7: Particular requirements for cord extension sets
GB/T 2423.4 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle)
GB/T 2423.7 Environmental testing - Part 2: Test methods - Test Ec: Rough handling shocks, primarily for equipment-type specimens
GB/T 2423.55 Environmental testing for electric and electronic products - Part 2: Test methods - Test Eh: Hammer tests
GB/T 2900.70-2008 Electrotecnical terminology - Electrical accessories
GB/T 2900.71-2008 Electrotechnical terminology - Electrical installations
GB/T 2900.73-2008 Electrotechnical terminology - Earthing and protection against electric shock
GB/T 4207 Method for the determination of the proof and the comparative tracking indices of solid insulating materials
GB/T 4208 Degrees of protection provided by enclosure (IP code)
GB/T 5013 (All parts) Rubber insulated cables of rated voltages up to and including 450/750V
GB/T 5023 (All parts) Polyvinyl chloride insulated cables of rated voltages up to and including 450/750V
GB/T 5169.10 Fire hazard testing for electric and electronic products - Part 10: Glow/hot-wire based test methods - Glow-wire apparatus and common test procedure
GB/T 5169.11 Fire hazard testing for electric and electronic products - Part 11: Glowing/hot-wire based test methods - Glow-wire flammability test method for end-products (GWEPT)
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 5465.1-2009 Graphical symbols for use on electrical equipment - Part 1: Overview and classification
GB/T 5465.2 Graphical symbols for use on electrical equipment - Part 2: Graphical symbols
GB/T 9797 Metallic and other inorganic coatings - Electrodeposited coatings of nickel, nickel plus chromium, copper plus nickel and of copper plus nickel plus chromium
GB/T 9799 Metallic and other inorganic coatings - Electroplated coatings of zinc with supplementary treatments on iron or steel
GB/T 10963.2 Electrical accessories - Circuit-breakers for overcurrent protection for household and similar installations - Part 2:Circuit-breakers for AC and DC operation
GB/T 12599 Metallic coatings - Electroplated coatings of tin - Specification and test methods
GB/T 15092.1 Switches for appliances - Part 1: General requirements
GB/T 16842-2016 Protection of persons and equipment by enclosures - Probe for verification
GB/T 16915 (All parts) Switches for household and similar fixed electrical installations
GB/T 17194 Conduits for electrical purposes - Outside diameters of conduits for electrical installations and threads of conduits and fittings
GB/T 20002.4-2015 Drafting for special aspects in standards - Part 4: Safety aspects for their inclusion in standards
GB/Z 40825-2021 Electrical accessories - Harmonization of general rules
GB/T 42710.2-2023 Direct current (DC) plugs and socket-outlets for household and similar purposes - Part 2: Types and dimensions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
Note 1: Throughout this document the word "earthing" is used for "protective earthing" unless otherwise stated.
Note 2: The term "accessory" is used as a general term covering plugs and socket-outlets; the term "portable accessory" covers plugs and portable socket-outlets. Examples of the use of accessories are shown in Figure 1a).
Note 3: Throughout this document the term "socket-outlet" covers both fixed and portable socket-outlets, except where the reference is specific to one type or the other.
3.1
plug
accessory having pins designed to engage with the socket-contacts of a socket-outlet, intended for frequent use by an ordinary person, and equipped with components for electrical connection of flexible cables and mechanical positioning
Note 1: For special purposes such as lighting chains (see also GB 7000.9), two or three single-core cables can be connected within the plug.
Note 2: For "ordinary person", see 195-04-03 of GB/T 2900.73-2008.
3.2
socket-outlet
accessory having socket-contacts designed to engage with the pins of a plug, intended for frequent use by an ordinary person, and equipped with terminal or termination for cable connection
3.3
fixed socket-outlet
socket-outlet intended to be connected to fixed wiring
3.4
portable socket-outlet
socket-outlet intended to be connected to or integral with one flexible cable and which can easily be moved from one place to another while connected to the supply
3.5
multiple socket-outlet
combination of two or more socket-outlets
Note: An example is shown in Figure 1b).
3.6
socket-outlet for appliances
socket-outlet integral with or intended to be installed or secured to an electrical installation
3.7
rewirable plug or rewirable portable socket-outlet
accessory so constructed that the flexible cable can be replaced
3.8
non-rewirable plug or non-rewirable portable socket-outlet
accessory integrated with the flexible cable after connection and assembly by the manufacturer (see 14.1)
3.9
moulded-on accessory
non-rewirable portable accessory the manufacture of which is completed by insulating material moulded around pre-assembled component parts and the terminations for the flexible cable
Contents of GB/T 42710.1-2023
Foreword i
Introduction ii
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Tests
6 Ratings
7 Classification
8 Marking
9 Checking of dimensions
10 Protection against electric shock
11 Provision for earthing
12 Terminals and terminations
13 Construction of fixed socket-outlets
14 Construction of plugs and portable socket-outlets
15 Interlocked socket-outlets
16 Resistance to ageing, protection provided by enclosures, and resistance to humidity
17 Insulation resistance and electric strength
18 Operation of earthing contacts
19 Temperature rise
20 Breaking capacity
21 Normal operation
22 Force necessary to withdraw the plug
23 Flexible cables and their connection
24 Mechanical strength
25 Resistance to heat
26 Screws, current-carrying parts and connections
27 Creepage distances, clearances and distances through sealing compound
28 Resistance of insulating material to abnormal heat, to fire and to tracking
29 Resistance to rusting
30 Additional tests on pins provided with insulating sleeves
Annex A (Normative) List of specimens required for test
Annex B (Normative) Safety-related routine tests for factory-wired portable accessories (protection against electric shock and correct polarity)
Annex C (Informative) Alternative gripping tests
Annex D (Normative) Switches incorporated in portable socket-outlets
Annex E (Normative) Hot wire ignition (HWI) test and arc ignition (AI) test
Bibliography
Figure 1 Examples of accessories
Figure 2 Pillar terminals
Figure 3 Screw terminals and stud terminals
Figure 4 Saddle terminals
Figure 5 Mantle terminals
Figure 6 Thread-forming screw
Figure 7 Thread-cutting screw
Figure 8 Examples of membranes and grommets
Figure 9 Test procedures for normal operation (see Clause 21)
Figure 10 Test wall in accordance with the requirements of 16.2.3
Figure 11 Apparatus for compression test of 24.6
Figure 12 Test plug used for 10.3
Figure 13 Probe for checking non-accessibility of live parts inside shutters
Figure 14 Probe for checking non-accessibility of live parts inside shutters, and of live parts of socket-outlets with increased protection
Figure 15 Apparatus for checking damage to conductors
Figure 16 Schematic diagram for bending test
Figure 17 Appliance for checking the resistance to lateral strain
Figure 18 Appliance for testing pins which are not solid
Figure 19 Schematic diagram of the clamping unit for temperature rise test
Figure 20 Apparatus for breaking capacity and normal operation test
Figure 21 Circuit diagrams for breaking capacity and normal operation tests
Figure 22 Apparatus for verification of maximum withdrawal force
Figure 23 Gauge for the verification of minimum withdrawal force
Figure 24 Apparatus for testing flexible cable retention
Figure 25 Apparatus for bending test
Figure 26 Sketches showing the application of the impacts according to Table 21
Figure 27 Apparatus for impact test at low temperature of 24.5
Figure 28 Apparatus for abrasion test on insulating sleeves of plug pins
Figure 29 Apparatus for mechanical strength test on multiple portable socket-outlets
Figure 30 Test apparatus to verify the retention of pins in the plug
Figure 31 Apparatus for test on cover or cover-plates
Figure 32 Gauge (thickness about 2 mm) for the verification of the outline of covers or cover-plates
Figure 33 Examples of application of the gauge of Figure 32 on covers fixed without screws on a mounting surface or supporting surface
Figure 34 Examples of application of the gauge of Figure 32 in accordance with the requirements of 24.16
Figure 35 Gauge for verification of grooves, holes and reverse tapers
Figure 36 -Sketch showing the direction of application of the gauge of Figure 35
Figure 37 Apparatus for compression test for the verification of resistance to heat specification of 25.5
Figure 38 Ball pressure test apparatus
Figure 39 Diagrammatic representation of 28.1.1
Figure 40 Apparatus for testing resistance to abnormal heat of insulating sleeves of plug pins
Figure 41 Apparatus for pressure test at high temperature
Figure 42 Impact test apparatus on pins provided with insulating sleeves
Figure C.1 Reference plug for gripping test
Figure C.2 Example of the test equipment for plug gripping test
Figure E.1 Apparatus for hot wire ignition test
Figure E.2 Circuit diagram for arc ignition test
Table 1 Preferred combinations of ratings
Table 2 Relationship between rated current and connectable nominal cross-sectional areas of copper conductors
Table 3 Values for pull test for screw-type terminals
Table 4 Composition of conductors
Table 5 Tightening torques for the verification of the mechanical strength of screw-type terminals
Table 6 Relationship between rated current and connectable cross-sectional areas of copper conductors for screwless terminals
Table 7 Value for pull test for screwless terminals
Table 8 Values for flexing under mechanical load test for copper conductors
Table 9 Test current for the verification of electrical and thermal stresses in normal use for screwless terminals
Table 10 Nominal cross-sectional areas of rigid copper conductors for bending test of screwless terminals
Table 11 Bending test forces for screwless terminals
Table 12 Forces to be applied to covers, cover-plates or actuating members whose fixing is not dependent on screws
Table 13 External cable dimension limits for surface-type socket-outlets
Table 14 Test current and nominal cross-sectional areas of copper conductors for temperature rise test
Table 15 Maximum and minimum withdrawal force for socket-outlets
Table 16 External dimensions of flexible cables to be accommodated by cable anchorages
Table 17 Torque test values for cable anchorages
Table 18 Maximum dimensions of flexible cables to be accommodated in rewirable accessories
Table 19 Relationship between rating of accessories, nominal cross-sectional areas of test conductors and test currents for the tests of temperature rise (Clause 19) and normal operation (Clause21)
Table 20 Type and length of the flexible cable of the cord extension set and the nominal cross-sectional area of the conductor
Table 21 Height of fall for impact tests
Table 22 Torque test values for cable glands
Table 23 Resistance to heat of different types or parts of accessories
Table 24 Creepage distances and clearances
Table 25 Creepage distances, clearances, and distances through insulating sealing compound
Table B.1 Diagrammatic representation of routine tests to be applied to factory-wired portable accessories
Table E.1 HWI and AI characteristics for materials required to secure current-carrying parts
Table E.2 HWI and AI characteristics for materials outside the scope of Table E.1
