ASTM D3032-21a

Standard Test Methods for Hookup Wire Insulation

ABSTRACT
These test methods detail the standard procedures for testing hookup wire insulations including all components of the insulation system used on single insulated conductors or an assembly of single insulated conductors such as a cable bundle and harness or flat ribbon cable. The insulating materials include not only the primary insulation over the conductor, but also insulating jackets over shielded constructions. The test procedures covered here shall be performed in the conditions or shall determine the properties, as follows: axial stability (longitudinal change) after thermal exposure; bondability to potting compounds; capacitance; cold bend test; concentricity; crush resistance; dielectric breakdown voltage; dimensions; dry-arc tracking; dynamic cut-through; fluid immersion; high temperature shock; insulation-continuity proof tests; insulation resistance; partial discharge (corona) inception and extinction voltage; relative thermal life and temperature index; strip force; surface resistance; tensile properties; vertical flame test; voltage rating of hook-up wire; voltage withstand test; and wet arc-tracking.
SCOPE
1.1 These test methods cover procedures for testing hookup wire.  
1.2 For the purposes of these test methods, hookup wire insulation includes all components of the insulation system used on single insulated conductors or an assembly of single insulated conductors such as a cable bundle and harness or flat ribbon cable. The insulating materials include not only the primary insulation over the conductor, but also insulating jackets over shielded constructions.  
1.3 These test methods and their locations are as follows:    
Section  
Axial Stability (Longitudinal Change) After Thermal Exposure  
20  
Bondability of Insulation to Potting Compounds  
18  
Capacitance  
9 to 11  
Cold Bend Test  
25  
Concentricity  
25  
Crush Resistance  
19  
Dielectric Breakdown Voltage  
5  
Dimensions  
14  
Dry-arc Tracking  
28  
Dynamic Cut-through  
21  
Fluid Immersion  
22  
High Temperature Shock  
23  
Insulation-Continuity Proof Tests  
12  
Insulation Resistance  
6  
Partial Discharge (Corona) Inception and Extinction Voltage  
24  
Relative Thermal Life and Temperature Index  
13  
Strip Force  
26  
Surface Resistance  
26  
Tensile Properties  
16  
Vertical Flame  
17  
Vertical Flame Test A  
18.5
(Test Method D8354)  
Vertical Flame Test B  
17.6 – 17.11.4  
Voltage Rating of Hook-Up Wire  
Annex A1  
Voltage Withstand Test  
8  
Wet Arc-tracking  
27  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.5 This standard measures and describes the response of materials, products, or assemblies to heat and flame under controlled conditions, but does not, by itself, incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies under actual fire conditions.  
1.6 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these tests.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see 17.1.3, 24.4, and Note 18.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2021
• ICS: 29.060.10 - Wires
• Technical Committee: D09 - Electrical and Electronic Insulating Materials
• Drafting Committee: D09.07 - Electrical Insulating Materials

Relations

• Refers: ASTM D1711-24 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Mar-2024
• Refers: ASTM D1868-20 - Standard Test Method for Detection and Measurement of Partial Discharge (Corona) Pulses in Evaluation of Insulation Systems
• Effective Date: 01-Mar-2020
• Refers: ASTM D149-20 - Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies
• Effective Date: 01-Jan-2020
• Refers: ASTM D3636-19 - Standard Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
• Effective Date: 01-Apr-2019
• Refers: ASTM D5032-19 - Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Glycerin Solutions
• Effective Date: 01-Mar-2019
• Refers: ASTM D1711-15 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Nov-2015
• Refers: ASTM D1711-14a - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Nov-2014
• Refers: ASTM D1711-14 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-May-2014
• Refers: ASTM D1711-13 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Nov-2013
• Refers: ASTM D1868-13 - Standard Test Method for Detection and Measurement of Partial Discharge (Corona) Pulses in Evaluation of Insulation Systems
• Effective Date: 01-Nov-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM D3636-13ae1 - Standard Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
• Effective Date: 01-Mar-2013
• Refers: ASTM D3636-13a - Standard Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
• Effective Date: 01-Mar-2013
• Refers: ASTM D3636-13 - Standard Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
• Effective Date: 01-Jan-2013
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011

Overview

ASTM D3032-21a: Standard Test Methods for Hookup Wire Insulation presents comprehensive procedures for evaluating the performance and integrity of insulation materials used in single insulated conductors, cable bundles, cable harnesses, and flat ribbon cables. Authored by ASTM International, this standard is critical for industries relying on hookup wire insulation in electrical and electronic applications. It encompasses testing not only the primary insulation over conductors but also insulating jackets over shielded wire constructions, ensuring safety, reliability, and compliance across a wide array of products and environments.

Key Topics

ASTM D3032-21a outlines an extensive array of test methods to ensure that hookup wire insulation meets rigorous quality and safety requirements. Key areas covered include:

• Thermal and Mechanical Endurance:

  • Axial stability after thermal exposure
  • Cold bend tests
  • Crush resistance
  • High-temperature shock
  • Tensile properties

• Electrical Performance Testing:

  • Dielectric breakdown voltage
  • Capacitance and capacitance unbalance
  • Insulation resistance
  • Partial discharge (corona) inception and extinction voltage
  • Voltage rating and voltage withstand tests
  • Surface resistance

• Chemical and Environmental Resistance:

  • Fluid immersion
  • Bondability to potting compounds

• Flammability and Safety:

  • Vertical flame tests (including Test Methods D8354)
  • Dry-arc and wet arc tracking

• Physical Measurements:

  • Dimensions and concentricity
  • Strip force for insulation removal

Each test in the standard is designed to assess specific properties that affect the service life, reliability, and safety of wiring insulation in various operational contexts.

Applications

ASTM D3032-21a is widely used in the electrical, automotive, aerospace, and electronics industries where the performance of hookup wire insulation is critical. Practical applications include:

• Product Qualification and Compliance: Manufacturers rely on these methods to verify that wire insulation fulfills essential quality requirements and regulatory standards.
• Quality Control during Production: The standard enables routine batch testing to detect defects, maintain consistency, and prevent costly failures.
• Design Verification: Engineers and designers use the test results to select appropriate insulation systems that will perform under expected mechanical, thermal, electrical, and environmental stress.
• Safety Assessments: The included flame resistance and electrical breakdown tests are vital for ensuring the finished product poses minimal risk in real-world fire or overload conditions.
• Supplier Evaluation: Procurement teams use adherence to ASTM D3032-21a as a criterion for supplier selection and incoming product inspection.

Related Standards

ASTM D3032-21a references and aligns with several internationally recognized standards, providing a coordinated approach to wire insulation testing. Notable related standards include:

• ASTM D149: Dielectric Breakdown Voltage and Dielectric Strength
• ASTM D150: AC Loss Characteristics and Permittivity of Solid Electrical Insulation
• ASTM D257: DC Resistance or Conductance of Insulating Materials
• ASTM D471: Effect of Liquids on Rubber Properties
• ASTM D638: Tensile Properties of Plastics
• ASTM D8354: Flammability of Electrical Insulating Materials for Wires or Cables
• IEEE 98 and 101: Guides for Thermal Evaluation of Electrical Insulating Materials

Utilizing ASTM D3032-21a in conjunction with these standards supports comprehensive validation of insulation system performance, helping maintain global best practices in the assessment of electrical wire and cable products.

Keywords: ASTM D3032-21a, hookup wire insulation, wire insulation testing, dielectric breakdown, flame resistance, electrical insulation, quality control, cable harness, ribbon cable, insulation resistance, capacitance testing, ASTM standards.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D3032 − 21a
Standard Test Methods for
Hookup Wire Insulation
This standard is issued under the fixed designation D3032; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 1.5 This standard measures and describes the response of
materials, products, or assemblies to heat and flame under
1.1 These test methods cover procedures for testing hookup
controlled conditions, but does not, by itself, incorporate all
wire.
factors required for fire hazard or fire risk assessment of the
1.2 For the purposes of these test methods, hookup wire
materials, products, or assemblies under actual fire conditions.
insulation includes all components of the insulation system
1.6 Fire testing is inherently hazardous. Adequate safe-
used on single insulated conductors or an assembly of single
guards for personnel and property shall be employed in
insulated conductors such as a cable bundle and harness or flat
conducting these tests.
ribbon cable. The insulating materials include not only the
1.7 This standard does not purport to address all of the
primary insulation over the conductor, but also insulating
safety concerns, if any, associated with its use. It is the
jackets over shielded constructions.
responsibility of the user of this standard to establish appro-
1.3 These test methods and their locations are as follows:
priate safety, health, and environmental practices and deter-
Section
mine the applicability of regulatory limitations prior to use.
Axial Stability (Longitudinal Change) After Thermal Exposure 20
For specific warning statements, see 17.1.3, 24.4, and Note 18.
Bondability of Insulation to Potting Compounds 18
Capacitance 9 to 11
1.8 This international standard was developed in accor-
Cold Bend Test 25
dance with internationally recognized principles on standard-
Concentricity 25
ization established in the Decision on Principles for the
Crush Resistance 19
Dielectric Breakdown Voltage 5
Development of International Standards, Guides and Recom-
Dimensions 14
mendations issued by the World Trade Organization Technical
Dry-arc Tracking 28
Barriers to Trade (TBT) Committee.
Dynamic Cut-through 21
Fluid Immersion 22
High Temperature Shock 23
2. Referenced Documents
Insulation-Continuity Proof Tests 12
Insulation Resistance 6
2.1 ASTM Standards:
Partial Discharge (Corona) Inception and Extinction Voltage 24
D149Test Method for Dielectric Breakdown Voltage and
Relative Thermal Life and Temperature Index 13
DielectricStrengthofSolidElectricalInsulatingMaterials
Strip Force 26
Surface Resistance 26
at Commercial Power Frequencies
Tensile Properties 16
D150Test Methods forAC Loss Characteristics and Permit-
Vertical Flame 17
tivity (Dielectric Constant) of Solid Electrical Insulation
Vertical Flame Test A 18.5
(Test Method
D257Test Methods for DC Resistance or Conductance of
D8354)
Insulating Materials
Vertical Flame Test B 17.6 – 17.11.4
Voltage Rating of Hook-Up Wire Annex A1 D374Test Methods for Thickness of Solid Electrical Insu-
Voltage Withstand Test 8
lation (Metric) D0374_D0374M
Wet Arc-tracking 27
D412TestMethodsforVulcanizedRubberandThermoplas-
1.4 The values stated in SI units are to be regarded as
tic Elastomers—Tension
standard. The values given in parentheses after SI units are
D471Test Method for Rubber Property—Effect of Liquids
provided for information only and are not considered standard.
D543Practices for Evaluating the Resistance of Plastics to
Chemical Reagents
These test methods are under the jurisdiction of ASTM Committee D09 on
Electrical and Electronic Insulating Materials and are the direct responsibility of
Subcommittee D09.07 on Electrical Insulating Materials. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2021. Published June 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1972. Last previous edition approved in 2021 as D3032–21. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D3032-21A. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3032 − 21a
D638Test Method for Tensile Properties of Plastics 3.2.1.1 Discussion—Capacitance unbalance is also called
D1711Terminology Relating to Electrical Insulation coefficient of asymmetry or capacitance asymmetry, and is
D1868Test Method for Detection and Measurement of expressed in percent unbalance.
Partial Discharge (Corona) Pulses in Evaluation of Insu-
3.2.2 cold bend test—a test in which a specimen is slowly
lation Systems
wrapped around a mandrel of a specified diameter after
D2303 Test Methods for Liquid-Contaminant, Inclined-
conditioning at a specified low temperature to determine that
Plane Tracking and Erosion of Insulating Materials
the primary insulation, primary jacket, overall jacket and any
D2307 Test Method for Thermal Endurance of Film-
other layer of the wire or cable specimen maintains sufficient
Insulated Round Magnet Wire
flexibility to withstand such bending at that low temperature
D2865Practice for Calibration of Standards and Equipment
without evidence of cracking.
for Electrical Insulating Materials Testing
3.2.3 relative thermal endurance—the comparison of the
D3183Practice for Rubber—Preparation of Pieces for Test
thermal endurance (as described by their Arrhenius plots) of
Purposes from Products
twoormoreinsulatedwiresdesignedforthesamespecificuse;
D3636Practice for Sampling and Judging Quality of Solid
this usually implies the same size of conductor, but the
Electrical Insulating Materials
insulation is of the thickness required for the particular use of
D3638Test Method for Comparative Tracking Index of
each insulation.
Electrical Insulating Materials
3.2.4 strip force—force required to remove a specified
D5032PracticeforMaintainingConstantRelativeHumidity
length of insulation from an insulated wire specimen as
by Means of Aqueous Glycerin Solutions
determined by a specified test procedure.
D5374TestMethodsforForced-ConvectionLaboratoryOv-
ens for Evaluation of Electrical Insulation 3.2.5 surface resistance, n—see Terminology D1711.
D5423Specification for Forced-Convection Laboratory Ov-
3.2.5.1 Discussion—For a fixed electrode separation, the
ens for Evaluation of Electrical Insulation measured surface resistance of a given hookup wire decreases
D6054Practice for Conditioning Electrical Insulating Mate-
as the diameter increases.
rials for Testing (Withdrawn 2012)
3.2.6 temperature index, n—see Terminology D1711.
D8354Test Method for Flammability of Electrical Insulat-
3.2.6.1 Discussion—Forhookupwire,thesymbolTIisused
ingMaterialsIntendedforWiresorCablesWhenBurning
for temperature index and the preferred use of the TI symbol
in a Vertical Configuration
implies a time of 20000 h obtained by analysis of aging data
E29Practice for Using Significant Digits in Test Data to
in which extrapolation is limited to no more than 25 °C below
Determine Conformance with Specifications
the lowest aging temperature. (See also Section 13.)
E691Practice for Conducting an Interlaboratory Study to
3.2.7 thermal end point curve, n—agraphicalrepresentation
Determine the Precision of a Test Method
ofathermalendpointataspecifiedagingtemperatureinwhich
2.2 IEEE Standards:
the value of a property of a material, or a simple combination
IEEE 98 Guide for the Preparation of Test Procedures for
of materials, is measured at room temperature and the values
the Thermal Evaluation of Electrical Insulating Materials
plotted as a function of time.
IEEE 101Statistical Analysis of Thermal Life Test Data
3.2.8 thermal end point time, n—the time necessary for a
2.3 Federal Standard:
specific property of a material, or a simple combination of
PPP-T-45CFederal Specification for Tape, Gummed; Paper,
materials, to degrade to a defined end point when aged at a
Reinforced and Plain, for Sealing and Securing (PPP-T-
specified temperature.
45C)
3.2.9 thermal endurance, n—see Terminology D1711.
3. Terminology
3.2.9.1 Discussion—The stability of hookup wire insulation
is estimated from changes in the results of voltage withstand
3.1 Definitions:
3.1.1 For definitions of terms used in these test methods, tests on hookup wire specimens that have been heat aged,
cooled to room temperature, flexed over a mandrel, immersed
refer to Terminology D1711.
3.2 Definitions of Terms Specific to This Standard: in salt water, and subjected to a specific applied voltage.
3.2.1 capacitance unbalance (of a pair in a shielded cable),
3.2.10 voltage withstand (proof-voltage) test—the applica-
n—the ratio, expressed as a percentage, of the difference in
tion of a specified voltage for a specified time to a specified
capacitance between each of two insulated conductors and the
configuration of the insulation. Results are expressed as “pass”
shield, to the capacitance between that conductor pair.
or “fail.”
4. Sampling
The last approved version of this historical standard is referenced on
4.1 Refer to the material specification for sampling plan
www.astm.org.
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
covering specific types of hookup wire insulations.
445 Hoes Ln., Piscataway, NJ 08854-4141, http://www.ieee.org.
5 4.2 Use Practice D3636 as a guide if the material specifi-
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. cation does not include a sampling plan.
D3032 − 21a
5. Dielectric Breakdown Voltage 6.2.1 Battery Jar, or other insulated vessel, large enough to
immerse the specimen, filled with water containing 0.05 to
5.1 Significance and Use:
0.10% wetting agent. The water bath shall serve as one
5.1.1 A detailed statement of significance is given in Ap-
electrode.
pendix X1 of Test Method D149.
6.2.2 UseapparatusdescribedinTestMethodsD257forthe
5.2 Apparatus:
resistance measurement.
5.2.1 Use the electrical apparatus described in Test Method
6.3 Test Specimens:
D149 for this test method.
6.3.1 The test specimen shall consist of a 8.3m (or 26-ft)
5.3 Test Specimens:
length of the insulated wire. Remove the insulation for a
5.3.1 The test specimen shall consist of insulated wire
distance of 25 mm (1 in.) at each end and twist the ends
610mm (24 in.) in length, or of the length required for the
together.
environmental exposure. Remove the insulation for a distance
6.4 Procedure:
of 25 mm (1 in.) at each end and twist the ends together.
6.4.1 Immerse the specimen to within 152 mm (6 in.) of the
5.4 Procedure:
twisted ends in the water bath, which is maintained at 23 6
5.4.1 Immersethetestspecimentowithin152mm(6in.)of
5°C (73 6 9 °F). Make an initial resistance measurement
the twisted ends in the water bath containing 5% sodium
between the conductor and the water bath for the purpose of
chloride (NaCl) and 0.05 to 0.10% wetting agent.
detectingnontypicalvalues.Discardanyspecimenwithagross
6,7
defect (that is, having an insulation resistance less than
NOTE 1—Triton X-100 has been found satisfactory for this test
method.
1×10 Ω between the conductor and the water bath) and
replace it with another specimen.
5.4.2 Use the water solution as the ground electrode, and
6.4.2 After 4 h, remeasure the resistance between the
apply the voltage to the twisted end of the conductor.
conductor and the water bath. Make the measurement at 500
5.4.3 Raise the voltage from zero at a rate of 500 V/s until
(610%) d-c V, after an electrification time of 1 min, unless
the specimen fails. If a flashover between the water solution
otherwise specified.
and the twisted ends of the wire occurs, discard the specimen
without retesting. Select longer specimens so that the distance
6.5 Calculation:
betweenthewatersolutionandtheendsofthewireissufficient
6.5.1 Calculate the insulation resistance as Ω·1000ft as
to prevent flashover.
follows:
5.5 Report:
insulationresistance, Ω 2 1000ft 5 ~R 3L!/1000 (1)
5.5.1 Report the following information:
where:
5.5.1.1 Description of the specimen,
R = measured resistance, Ω, and
5.5.1.2 Voltage at which breakdown occurred,
L = immersed length, 25 ft.
5.5.1.3 Descriptionofanypreviousenvironmentalexposure
given to the specimen before testing, and
6.5.2 Calculate the insulation resistance as Ω-1000 m as
5.5.1.4 Conditions under which the test was run.
follows:
insulationresistance, Ω 2 1000m 5 ~R 3L'!/1000 (2)
6. Insulation Resistance
where:
6.1 Significance and Use:
L' = immersed length, 8 m.
6.1.1 In high impedance circuits, insulation resistance is
NOTE 3—Do not express insulation resistance as Ω·m since this unit
functionally important. In some cases, changes in insulation
describes resistivity. It must be used as Ω for some unit of length.
resistanceindicatesdeteriorationofotherproperties.Insulation
6.6 Report:
resistance is also useful for quality control.
6.6.1 Report the following information:
NOTE2—Theterm“insulationresistance”isastandardtermusedinthe
6.6.1.1 Description of the specimen,
hookup wire industry to designate the resistance of a specified length of
6.6.1.2 Immersed length of the specimen,
insulated wire, normally expressed as Ω-1000 ft. This is not a true
6.6.1.3 Applied voltage,
insulation resistance since a resistance for a known length can be
calculated and, also, the tests are conducted in a manner to eliminate
6.6.1.4 Time of electrification,
surface conduction. The value obtained in this type of measurement is
6.6.1.5 Immersion time,
actually a volume resistance, but will be referred to here as insulation
6.6.1.6 Measured resistance,
resistance to avoid confusion in the hookup wire industry.
6.6.1.7 The insulation resistance of the specimen calculated
6.2 Apparatus:
in Ω -1000 ft (or in Ω-1000 m), and
6.6.1.8 Number of specimens discarded.
Triton X-100 is a trademark of The Dow Chemical Company, Midlands,
7. Surface Resistance
Michigan, http://www.dow.com.
The sole source of supply of the Triton X-100 known to the committee at this
7.1 Significance and Use:
time is The Dow Chemical Company. If you are aware of alternative suppliers,
7.1.1 At high humidities, surface conduction is responsible
please provide this information to ASTM International Headquarters. Your com-
for the largest part of the leakage current in service (for
ments will receive careful consideration at a meeting of the responsible technical
committee, which you may attend. example, at the terminations of bundled hookup wires).
D3032 − 21a
7.1.2 Additional statements on the significance of surface
resistance are contained in Test Methods D257.
7.2 Apparatus:
7.2.1 Test Chamber—A vessel fitted with a cover through
which leads have been sealed will provide a suitable test
chamber.Anappropriatematerialfortheleadsispolytetrafluo-
roethylene (PTFE)-insulated wire, sealed with paraffin wax or
silicone grease as they pass through the cover. The use of
PTFE-insulated feed-through bushings in place of the wires is
acceptable (Fig. 1).
7.2.2 As an alternative method, it is acceptable to use a
paraffin wax collar fitted to the top of a glass vessel and
tin-coated size 1.02 mm (AWG No. 18) solid copper wires,
which are sealed through the paraffin wax. A glass cover is
appropriate to seal the top of the test chamber (Fig. 2).
7.2.3 Use the test instruments described in Test Methods
D257 for the resistance measurement.
7.2.4 The electrical resistance of the chamber, measured
between the lead wires under the conditions given in 7.3 with
no specimens in place, shall be greater than 10 Ω.
7.3 Test Specimens:
FIG. 2 Typical Surface Resistance Test Chamber Using Paraffin
7.3.1 Measure five specimens.
Wax Collar
7.3.2 The specimens shall consist of 152 mm (6-in.) lengths
of finished wire, cleaned in accordance with the procedure
recommended by the manufacturer. Handle the specimens (1.0 60.005in.) apart between their nearest edges. Each
subsequently with maximum care, preferably with clean lint- electrodeshallbeapproximately13mm( ⁄2in.)wide,andshall
freeglovestoavoideventheslightestcontamination,including consist of conductive silver paint painted around the circum-
direct contact with the fingers. Provide each cleaned specimen ference of the specimen. Make electrical connection to the dry
near its center with two electrodes spaced 25.4 6 0.1 mm electrodes by wrapping several turns of fine tin-coated copper
FIG. 1 Typical Surface Resistance Test Chamber Using Feed-through Bushings
D3032 − 21a
wire (0.361mm (AWG No. 27) or finer) around the electrode, 8.3.2 Replace any specimen having an initial gross flaw
leaving a free end of the fine wire of sufficient length for (that is, having an insulation-resistance less than 1×10 Ω
connecting to the electrical lead wires inside the test chamber. between the conductor and the solution) before exposure to
environmental conditioning.
7.4 Conditioning:
7.4.1 Measure the surface resistance after an exposure time 8.4 Procedure:
of 96 h before removing the specimens from the test chamber. 8.4.1 Immerse the test specimen to within 51 mm (2 in.) of
7.4.2 Maintain the conditions in the test chamber within the twisted ends in the water solution described in 8.2.2.
62°Cofatemperatureselectedintherangefrom18to27°C, 8.4.2 Measure the resistance between the conductor and the
and within 62% relative humidity of a relative humidity water solution at 500 (610%) dc V to detect gross flaws
selected in the range from 90 to 96% relative humidity. (8.3.2). Use the apparatus described in Test Methods D257 for
7.4.3 Maintain the relative humidity over an aqueous glyc- the resistance measurement.
erin solution described in Practice D5032.
NOTE 6—This screening test is performed before environmental expo-
sure and is not repeated after the exposure.
NOTE4—Theallowabletemperaturevariationforagivensolutionmust
bekeptwithinthenecessaryrangetomaintaintherelativehumidityinthe
8.4.3 After a 4-h soak, apply the voltage between the
chamber to the required limits.
twisted ends of the conductor and the grounded water, increas-
7.5 Procedure:
ing from zero to the specified value at a rate of 500 V/s. Hold
7.5.1 After the conditioning period stated in 7.3, measure
the voltage on the specimen for 1 min, or for the time required
the resistance between the electrodes after an electrification
in the applicable specification.
time of 1 min at 500 (610%) dc V.
8.5 Report:
NOTE5—Insometestmethodsthemeasuredresistanceismultipliedby
8.5.1 Report the following information:
the outside diameter of the insulation. It is important that the values so
8.5.1.1 Description of the specimen,
calculated not be confused with the measured values nor with the true
8.5.1.2 Electrification time and voltage,
surface resistivity of the specimen.
8.5.1.3 Descriptionoftheenvironmentalexposuregiventhe
7.6 Report:
specimen before test,
7.6.1 Report the following information:
8.5.1.4 Whether or not the specimen withstood the required
7.6.1.1 Description of the specimen,
voltage for the specified time,
7.6.1.2 Diameter of the specimen,
8.5.1.5 Time for failure in case failure occurs, and
7.6.1.3 Test conditions (temperature and relative humidity),
8.5.1.6 Number of specimens discarded.
7.6.1.4 Applied voltage, and
9. Capacitance of Shielded, Single-conductor Hookup
7.6.1.5 Measured surface resistance.
Cable
8. Voltage Withstand Test
9.1 Significance and Use:
8.1 Significance and Use: 9.1.1 Capacitance per unit length is useful for quality
8.1.1 This test method is useful as a screening test for control and is sometimes required for electronic circuit design
eliminatingspecimensunsuitableforfurthertesting.Itsalsoan purposes.
acceptable method to determine whether exposure to environ- 9.1.2 Additional statements on the significance of capaci-
mental test conditions has reduced the breakdown strength tance are found in Test Methods D150.
below some prescribed level.
9.2 Apparatus:
8.2 Apparatus: 9.2.1 UsetheapparatusdescribedinTestMethodsD150for
8.2.1 Use the electrical apparatus described in Test Method this test method.
D149 for this test method.
9.3 Test Specimens:
8.2.2 Water Bath, containing 5% sodium chloride (NaCl)
9.3.1 The specimen shall consist of a piece of shielded
and 0.5 to 0.10% wetting agent.
hookup cable approximately 3 m (10 ft) in length.
8.2.3 Thesensitivityofthetestequipmentshallbesuchthat
9.3.2 Remove the jacket, if any, for a distance of 25 mm
a fault is indicated when one half of the specified test voltage
(1in.)fromoneendofthespecimenandunbraidtheshieldfor
isappliedtotheconductorofalengthof0.644mm(AWGNo.
this distance. Remove the insulation from the conductor for a
22) stranded insulated wire whose other end, with the insula-
distance of 13 mm ( ⁄2 in.). Twist the unbraided shield
tion cut flush with the conductor, is inserted 6.4 mm ( ⁄4 in.)
conductorstogetherforconnectiontothemeasuringinstrument
into the test solution as far from the ground electrode as the
and to prevent slippage of the shield on the insulation.Apiece
specimen to be tested. Add more NaCl, if necessary, to the
of tape over the shield is an appropriate means to prevent
solution to meet these conditions. Fault-indicating equipment
slippage.
is described in Test Method D149.
9.3.3 Terminatetheoppositeendofthespecimenbycutting
8.3 Test Specimens: all parts of the specimen flush and perpendicular to the axis.
8.3.1 The test specimen shall consist of insulated wire Take care to maintain concentricity of the specimen where it is
610mm (24 in.) in length, or of the length required for cut. Use tape around the shield of an unjacketed specimen to
environmental exposure. Remove the insulation for a distance prevent slippage as long as the tape does not come in contact
of 25mm (1 in.) at each end and twist the ends together. with the insulation or the conductor.
D3032 − 21a
9.3.4 As an alternative method, prepare both ends of the 10.4.6 Measurethelengthoflayofthetwistedpairafterthe
specimeninaccordancewith9.3.2.Whenthisisdone,twistthe shield has been removed. The lay of the helically wound
conductors from both ends of the specimen together for insulatedconductorsistheaxiallengthofoneturnofthehelix.
connectiontothemeasuringinstrument.Itisacceptableforthe
10.5 Calculation:
shields to also be twisted together.
10.5.1 Calculate the capacitance between the two
9.3.5 Use the distance in which the shield is in contact with
conductors, C, as follows:
the insulation as the effective length of the specimen.
C 5 2 C 1C 2 C /4 2 C 2 C /4 C (3)
@~ ~ ! ! # @~ ! #
a b c a b c
9.4 Procedure:
NOTE8—Thesecondtermofthisequationisfrequentlyneglectedwhen
the difference between C and C is small.
9.4.1 Connect the specimen to the measuring instrument
a b
and measure the capacitance. Subtract the capacitance of the
10.5.2 Calculate the percent capacitance unbalance as fol-
terminals from the measured capacitance value (Note 7).
lows:
NOTE 7—Detailed instructions for making the measurements needed to capacitanceunbalance,% 5 C 2 C /C 3100 (4)
@~ ! #
a b
obtainthecapacitanceandformakinganynecessarycorrectionsduetothe
10.6 Report:
measuring circuit are given in the instruction books supplied with
10.6.1 Report the following information:
commercial equipment.
10.6.1.1 Description of the specimen,
9.5 Report:
10.6.1.2 Effective length of the specimen,
9.5.1 Report the following information:
10.6.1.3 Frequency at which the measurements were made,
9.5.1.1 Description of the specimen,
10.6.1.4 Temperature and relative humidity at which the
9.5.1.2 Effective length of the specimen,
measurements were made,
9.5.1.3 Frequency at which the measurement was made,
10.6.1.5 Capacitance measured in 10.4.3, C ,
a
9.5.1.4 Temperature and relative humidity at which the
10.6.1.6 Capacitance measured in 10.4.4, C ,
b
measurement was made,
10.6.1.7 Capacitance measured in 10.4.5, C ,
c
9.5.1.5 Measured capacitance, and
10.6.1.8 Capacitance calculated in 10.5.1,
9.5.1.6 Capacitance of the specimen calculated in capaci-
10.6.1.9 Capacitancebetweenthetwoconductors,picofarad
tance per ft (picofarad per ft) or capacitance per m (picofarad
per ft (capacitance per ft) or picofarad per m (capacitance per
per m).
m),
10.6.1.10 Length of lay of the twisted pair after the shield
10. Capacitance and Capacitance Unbalance of Shielded
has been removed in metres or inches, and
Two-conductor Hookup Cable
NOTE 9—Lay is sometimes expressed in twists per m or twists per ft.
10.1 Significance and Use:
10.6.1.11 Capacitance unbalance calculated in 10.5.2.
10.1.1 Capacitance per unit length and capacitance unbal-
ance are useful for quality control, and sometimes required for
11. Capacitance of Unshielded Twisted Pair Hookup
electronic circuit design purposes.
Wire
10.2 Apparatus:
11.1 Significance and Use:
10.2.1 Use the electrical apparatus described in Test Meth-
11.1.1 Capacitance per unit length is useful for quality
ods D150 for this test method.
control and is sometimes required for electronic circuit design
purposes.
10.3 Test Specimens:
10.3.1 Prepare the specimen in accordance with 9.3, except
11.2 Apparatus:
that the insulation at one end shall be removed from both
11.2.1 Use the electrical apparatus described in Test Meth-
conductors for a distance of 13 mm ( ⁄2 in.).
ods D150 for this test method.
10.4 Procedure: 11.3 Test Specimens:
11.3.1 The specimen shall consist of a piece of twisted pair
10.4.1 Designate one conductor as No. 1, the other conduc-
hookup wire approximately 3 m (10 ft) in length.
tor as No. 2, and the shield as No. 3.
11.3.2 Remove the jacket, if any, for a distance of 25 mm
10.4.2 The shield will be connected to one terminal of the
(1in.),ortapethewirestogether1in.backfromoneendofthe
measuring instrument for all three measurements needed to
twisted pair. Remove 13 mm ( ⁄2 in.) of the insulation from
determine the capacitance of this type of specimen.
both conductors.
10.4.3 Measure the capacitance between conductor No. 2 at
11.3.3 Ifthesampleisnotjacketed,tapetheotherendofthe
one terminal of the measuring instrument and No. 1 and No. 3
specimen to prevent the wires from untwisting during mea-
at the other terminal (Note 7). This capacitance value is C .
a
surement.
10.4.4 Measure the capacitance between conductor No. 1 at
11.3.4 The length that the two wires are in contact will be
one terminal and No. 2 and No. 3 at the other terminal. This
used as the effective specimen length (Fig. 3).
capacitance value is C .
b
10.4.5 Measure the capacitance between conductors No. 1 11.4 Procedure:
and No. 2 at one terminal and No. 3 at the other terminal.This 11.4.1 Suspend the uncoiled specimen at least 0.9 m (3 ft)
value of capacitance is C . awayfrompossiblegroundplanes,suchasworkbenches,table
c
D3032 − 21a
such defects either as an in-process procedure or during the
final spooling operation, whichever is applicable.
12.2.2 This test method is used as a manufacturing control
test, as an acceptance test immediately prior to final packaging
by the producer, or as an incoming inspection by the user. In
the case of its use as an acceptance test by a user, reach an
agreementbetweentheproducerandtheuserastowhichproof
test method is mutually acceptable, and specify that method in
in. mm
⁄2 13
the applicable product or purchase specification.
12.2.3 Possible damage in handling, degradation caused by
FIG. 3 Effective Specimen Length
repeatedtesting(eachvoltagetesthasthepotentialtolowerthe
ability of the wire to withstand subsequent voltage tests), and
tops, floors, etc. Use any insulating material to hang the variations in test parameters will separately or in combination
specimen in the appropriate position. produce differences that make the comparison of results
11.4.2 Connect the specimen to the measuring instrument between the producer and the user difficult.
12.2.4 The insulation-continuity proof test is superior to a
and measure the capacitance. Subtract the capacitance of the
terminals from the measured capacitance value (Note 6). water-immersion test in that defects are able to be found and
the bad sections are able to be removed during the spooling
11.4.3 Measure the length of lay of the twisted pair.The lay
ofthehelicallywoundinsulatedconductoristheaxiallengthof operation without damaging good insulation. Because the
waterbathiseliminated,thepossibilityofcontaminationofthe
one turn of the helix.
insulated conductor is avoided.
NOTE10—Thecapacitanceoftwistedpairhookupwireisdependenton
thelengthoflay.Highercapacitancevalueswillbeobtainedonspecimens 12.3 Apparatus,TestMethodA—Repeated-impulseMethod:
of the same material with shorter lengths of lay.
8,9
NOTE 11—The Model IT-25 Impulse Test Calibration Set is for
11.5 Report:
performing the single-shot test as well as for checking compliance with
11.5.1 Report the following information:
the requirements for capacitance tolerance and failure sensitivity.
11.5.1.1 Description of the specimen,
12.3.1 Electrode—The electrode consists of a bead chain
11.5.1.2 Effective length of the specimen,
construction that will give intimate metallic contact with the
11.5.1.3 Frequency at which the measurements were made,
wire insulation surface. The chain must be suspended in a U-
11.5.1.4 Temperature and relative humidity at which the
or V-shaped trough having a width approximately 40 mm or
measurements were made, 1
1 ⁄2in. greater than the diameter of the largest size of wire that
11.5.1.5 Measured capacitance,
istested.Thechainmusthavealengthappreciablygreaterthan
11.5.1.6 Capacitance of the specimen calculated, picofarads
the depth of the enclosure so that the beads will droop below
per ft (capacitance per ft) or picofarads per m (capacitance per
thewireundertest.Theelectrodeassemblyconsistsofanarray
m), and
of approximately 1.6 mm or ⁄16in. diameter stainless steel
11.5.1.7 Lengthoflayofthetwistedpairininchesormetres
bead chains suspended approximately 2.0 mm or 0.08 in. apart
(Note 10).
perpendicular to the direction of wire movement (wire line)
and spaced approximately 2.5 mm or 0.10 in. apart along the
12. Insulation-continuity Proof Tests
wire line. The electrode length must be chosen so that at the
12.1 Scope:
speed being used, the wire shall be subjected to no less than
12.1.1 Insulation-continuity of hookup wire is tested by one
three nor more than 100 pulses at any given point. Only one
of the following methods:
electrode will be connected to the power supply transformer.
12.1.1.1 Test Method A, Repeated-impulse Method—See
The electrode must be kept free of water and foreign matter; it
12.3.
must be provided with an earth grounded metal screen or
12.1.1.2 Test Method B, 3000-Hz Sinusoidal-voltage
equivalent guards to provide protection for the operating
Method—See 12.8.
personnel. Broken chains must be promptly replaced as re-
12.1.2 Thesetestmethodsareintendedtoapplyprimarilyto
quired.
the final inspection of wire for the purpose of finding and
12.3.2 Power Supply—Use any impulse generator that
eliminating defects prior to shipment or before use.
meets the requirements of Section 12.
12.1.3 These test methods are also applicable to in-process
12.3.2.1 TestImpulse—Thewaveformofthevoltageapplied
testing to eliminate defects at an early stage of manufacture
to the electrode head shall consist of a negative pulse, the peak
(that is, for wire for use in multiple-conductor cables or
magnitude of which shall be specified for the wire under test,
jacketed constructions).
12.2 Significance and Use: 8
The Model IT-25 Impulse Test Calibration Set is a trademark of The Clinton
12.2.1 In the manufacture of hookup wire, it is desirable to
Instrument Co., Clinton, CT, www.clintoninstrument.com.
The sole source of supply of the Model IT-25 Impulse Test Calibration Set
have long continuous lengths. Therefore, bare wire, splices,
known to the committee at this time isThe Clinton Instrument Co. If you are aware
and other defects usually are not removed until the final stages
of alternative suppliers, please provide this information to ASTM International
of production. The insulation-continuity proof test serves as a
Headquarters.Your comments will receive careful consideration at a meeting of the
100% screening test to locate and permit the removal of all responsible technical committee, which you may attend.
D3032 − 21a
followed by a damped oscillation. The peak impulse voltage thetake-upspool.Thespeedofpassageofthewirethroughthe
shall be stipulated in the applicable material specification. The electrodeshallbesuchthat,afterstart-up,thewireissubjected
rise time of the negative impulse wave from zero magnitude to to not less than three nor more than 100 pulses at any given
90%ofthespecifiedpeakvoltageshallbenotmorethan75µs. point. Cut out, or mark for later removal, all sections of wire
The peak value of the first positive overshoot and of the
thatcausethedetectortotrip,alongwithatleast50mm(2in.)
subsequentdampedoscillationsshallbesmallerthantheinitial of wire on each side of the failure. Locate the point of failure
negative pulse. The time during which the absolute magnitude
by passing the wire back through the head. If the detector does
of each voltage pulse and accompanying damped oscillation not trip again it is likely that the indication was false. Make
(positiveandnegative)remainsatavalueof80%orgreaterof
every effort to test the entire length, including ends of the wire
the specified peak voltage shall be 20 to 100 µs. The pulse when stringing up new lengths, in accordance with this
repetition rate shall be 200 to 250 pulses/s. Except for the final
procedure.Removeallendsorotherportionsofthewirenotso
peak voltage adjustment (12.6) conformity with these impulse
tested. When testing wire in process, or when specified in
test parameters shall be determined with no capacitive load
contract or order, dielectric failures, untested portions of wire,
impressed on the electrode.
or portions that have been exposed to fewer or more than the
12.3.2.2 Capacitive Tolerance—The tolerance of the equip- specified number of pulses are marked by stripping the
ment to change in capacitive load shall be such that the peak insulation or by any other suitable method of marking as
output voltage shall be reduced by not more than 12% in the
specified in the contract in instead of being cut out of the wire.
event of an increase of the capacitive load, between electrode
12.7 Report—If required in sales to customers the producer
and ground, from an initial load of 4.9 to 9.8 pF/cm (12.5 to
shall certify that 100% of wire supplied has been tested in
25pF⁄in.) of electrode length.
accordance with Section 12 of these test methods.
12.3.2.3 Instrument Voltmeter—A peak-reading voltmeter
shall be provided, indicating continuously the potential of the 12.8 Apparatus, Test Method B—3000-Hz Sinusoidal-
voltage Method:
electrode. The voltmeter shall have a minimum accuracy of
63% at the specified impulse potential, after calibration as
12.8.1 Electrode—The electrode consists of a bead chain
specified in 12.4.
construction that will give intimate metallic contact with the
12.3.2.4 Failure Detection Circuit—There shall be a failure wire insulation surface. The chain must be suspended in a U-
detection circuit to give a visual or audible indication, or both,
or V-shaped trough having a width approximately 40 mm or
ofinsulationfailure.Inaddition,de-energizetheelectrodehead 1 ⁄2 in. greater than the diameter of the largest wire that is
and stop the drive mechanism. The detection circuit shall be
tested. The chain must have a length appreciably greater than
sufficiently sensitive to indicate a fault at 75% of the specified the depth of the enclosure so that the beads will droop below
test voltage when the electrode is arced to ground through a
thewireundertest.Theelectrodeassemblyconsistsofanarray
20kΩ resistor and shall be capable of detecting a fault that of approximately 1.6 mm or ⁄16 in. diameter stainless steel
lasts for the duration of only one impulse.
bead chains suspended approximately 2.0 mm or 0.08 in. apart
perpendicular to the direction of wire movement (wire line)
12.4 Calibration—Calibrate the instrument voltmeter peri-
and spaced approximately 2.5 mm or 0.10 in. apart along the
odically (see Practice D2865) by comparison with an external
wire line. The electrode length must be chosen so that at the
standard voltmeter having an accuracy of 62% of the reading
speed being used, the wire will be subjected to no less than a
and capable of detecting the peak potential at the electrode
total of 18 positive and negative crests of the supply voltage
head, with or without auxiliary circuitry. In performing the
(the equivalent of nine cycles) nor more than 2000 positive or
calibration, connect the standard voltmeter to the electrode
negativewavecrests(1000completecycles)atanygivencross
head directly or through a calibrated attenuator circuit. Adjust
section. Only one electrode will be connected to the power
the impulse generator until the reading on the standard volt-
supply transformer. The electrode must be kept free of water
meter is the specified potential, at which point the reading on
andforeignmatter;itmustbeprovidedwithanearthgrounded
the instrument voltmeter shall be observed and recorded.
metal screen or an equivalent guard to provide protection for
Repeat this calibration for each peak potential at which it is
the operating personnel. Broken chains must be promptly
intended to operate the equipment.An alternative procedure is
replaced.
by means of a calibrated oscilloscope connected to the elec-
12.8.2 Power Supply—Use any 3000-Hz sinusoidal genera-
trode through a suitable attenuator. The peak magnitude of the
tor meeting the requirements of 12.8.2.1 – 12.8.2.5.
negative impulse is then directly readable from the waveform
display. Conformance to the other waveform parameters speci- 12.8.2.1 Waveform—The waveform of the voltage applied
to the electrode head shall consist of a 3000 6 500-Hz sine
fied in 12.3.2.1 shall be verified from the oscilloscope.
wave, the amplitude of which shall be as specified for the wire
12.5 Test Specimens—The test specimens consist of con-
under test and shall not change more than 62% as the line
tinuous lengths of hookup wire.
voltage varies 615 V from the nominal. Unless otherwise
12.6 Procedure—Thread the wire through the electrode and specified, the alternating voltage (root mean square) shall be
groundtheconductoratone,orpreferablyboth,ends.Energize the voltage called for in the applicable material specification.
the electrode to the specified peak potential and, after final Theratioofthepeakvaluetotherootmeansquarevalueofthe
adjustment of the voltage with the wire in the electrode head, voltageshallbenolessthan1.35normorethan1.48underany
passthewirefromthepay-offspoolthroughtheelectrodeonto load condition.
D3032 − 21a
12.8.2.2 Regulation—The current which the equipment is electrode to the specified potential and, after final adjustment
able to deliver to a purely capacitive load shall be no less than ofthevoltagewiththewireintheelectrodehead,passthewire
40 mA. The current able to be delivered to a purely resistive from the pay-off spool through the electrode onto the take-up
load shall be no less than 12 mA. When the load consists of a spool at a speed not exceeding that used in 12.8.1 to determine
capacitance passing a current of 10 mA in parallel with a the electrode length. Cut out, or mark for later removal, all
resistancepassingacurrentof1mAthevoltageatthetestload sections of wire that cause the detector to trip, along with at
shall not change more than 5% between no-load and full-load least 2 in. of wire on each side of the failure. Locate the point
conditions. of failure by passing the wire back through the head. If the
12.8.2.3 Instrument Voltmeter—An average indicating volt- detector does not trip again, it is likely that the indication was
meter capable of operating accurately at a frequency of up to false. Every effort shall be made to test the entire length,
4000 Hz and calibrated to read root mean square values shall including ends, of the wire when stringing up new lengths, in
be provided. It shall continuously indicate the potential on the accordance with this procedure. Remove all ends or other
electrode. This a-c (root mean square) voltmeter, shall have an portions of the wire not tested. For final testing of wire, or
accuracy tolerance of not more than 63% at the specified when specified in product or purchase specification, dielectric
potentials, after calibration as specified in 12.9.2 and shall be failures, untested portions of wire, or portions that have been
energized by a metering winding unity, coupled to the high- exposed to fewer or more than the specified number of pulses
voltage secondary winding. are marked by stripping the insulation or by any other suitable
12.8.2.4 Failure Detection Circuit—There shall be a failure method of marking as specified in the product or purchasing
detection circuit to give a visual or audible indication, or both, specification in instead of being cut out of the length.
of insulation failure. In addition, the electrode head is de-
12.12 Report:
energized and the drive mechanism stopped. The system shall
12.12.1 When specified, the report shall consist of a certi-
besufficientlysensitivesothatafaultisindicatedat2kVwhen
fication that 100% of the wire supplied has been tested in
the electrode is arced to the ground through a needle spark gap
accordancewithoneofthemethodsspecifiedinthissection,at
in series with the detection circuit for a duration of 0.001 s or
the voltage called for in the applicable product or purchasing
less.
specification. The particular method employed shall be re-
NOTE12—Constructatestsetforcheckingsensitivityusingaturntable,
ported.
withagroundedmetalplateatitsperiphery,rotatedtomovetheplatepast
a 0.13 mm (0.005 in.) phosphor bronze wire, positioned normal to the
12.13 Precision and Bias:
plate’s surface, in 0.001 s. The wire shall be spaced 0.15 mm (0.006 in.)
12.13.1 No statement is made about either the precision or
from the plate, and connected electrically to the output voltage of the
the bias of these test methods for measuring insulation-
apparatus for the duration of a single pass.
continuity since the result merely states whether there is
12.8.2.5 Response After Failure Detection— The stability
conformancetothepass/failcriteriaspecifiedintheprocedure.
andrecoveryofthegeneratorandassociateddetectioncircuitry
shall be such that the waveform and regulation meet the
13. Relative Thermal End Point Time and Temperature
requirementsforthepowersupplyandwillmaintainthesettest
Index
potential 40 ms after failure detection.
13.1 Scope:
12.9 Calibration of Equipment:
13.1.1 This test method provides a standard test and proce-
12.9.1 Calibratetheinstrument’svoltmeterperiodically(see
durefordeterminingthermalendpointtimeversustemperature
Practice D2865) by comparison with an external electrostatic
curvesandtemperatureindicesforflexibleelectricalinsulating
voltmeter, with or without auxiliary circuitry, having a 61%
materialsandinsulatingsystemsusedasprimaryinsulationand
full-scale accuracy. The measurements shall be made in the
primary jackets on hookup wire whose conductor type is that
uppertwo-thirdsofthestandardvoltmeterscale.Inperforming
used in practice.
the calibration, connect the standard voltmeter to the electrode
head directly.Adjust the voltage generator until the reading on
13.2 Summary of Test Method:
the standard voltmeter is the specified potential, at which point
13.2.1 Foursetsofspecimensofagivensampleofinsulated
thereadingontheinstrument’svoltmetershallbeobservedand
wire shall be exposed for selected periods of time at several
recorded.Repeatthiscalibrationforeachpotentialatwhichthe
fixed temperatures.After each exposure period the specimen is
equipment is intended to operate.
wrapped on a mandrel to simulate a flexi
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3032 − 21 D3032 − 21a
Standard Test Methods for
Hookup Wire Insulation
This standard is issued under the fixed designation D3032; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 These test methods cover procedures for testing hookup wire.
1.2 For the purposes of these test methods, hookup wire insulation includes all components of the insulation system used on single
insulated conductors or an assembly of single insulated conductors such as a cable bundle and harness or flat ribbon cable. The
insulating materials include not only the primary insulation over the conductor, but also insulating jackets over shielded
constructions.
1.3 These test methods and their locations are as follows:
Section
Axial Stability (Longitudinal Change) After Thermal Exposure 21
Axial Stability (Longitudinal Change) After Thermal Exposure 20
Bondability of Insulation to Potting Compounds 19
Bondability of Insulation to Potting Compounds 18
Capacitance 9 to 12
Capacitance 9 to 11
Cold Bend Test 26
Cold Bend Test 25
Concentricity 26
Concentricity 25
Crush Resistance 20
Crush Resistance 19
Dielectric Breakdown Voltage 5
Dimensions 15
Dimensions 14
Dry-arc Tracking 29
Dry-arc Tracking 28
Dynamic Cut-through 22
Dynamic Cut-through 21
Fluid Immersion 23
Fluid Immersion 22
High Temperature Shock 24
High Temperature Shock 23
Insulation-Continuity Proof Tests 13
Insulation-Continuity Proof Tests 12
Insulation Resistance 6
Partial Discharge (Corona) Inception and Extinction Voltage 25
Partial Discharge (Corona) Inception and Extinction Voltage 24
These test methods are under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and are the direct responsibility of Subcommittee
D09.07 on Electrical Insulating Materials.
Current edition approved Jan. 1, 2021April 1, 2021. Published February 2021June 2021. Originally approved in 1972. Last previous edition approved in 20162021 as
D3032 – 16.D3032 – 21. DOI: 10.1520/D3032-21.10.1520/D3032-21A.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3032 − 21a
Relative Thermal Life and Temperature Index 14
Relative Thermal Life and Temperature Index 13
Strip Force 27
Strip Force 26
Surface Resistance 27
Surface Resistance 26
Tensile Properties 17
Tensile Properties 16
Vertical Flame 18
Vertical Flame 17
Vertical Flame Test A 18.5
(Test Method
D8354)
Vertical Flame Test B 18.6 – 18.11.4
Vertical Flame Test B 17.6 – 17.11.4
Voltage Rating of Hook-Up Wire Annex A1
Voltage Withstand Test 8
Wet Arc-tracking 28
Wet Arc-tracking 27
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
1.5 This standard measures and describes the response of materials, products, or assemblies to heat and flame under controlled
conditions, but does not, by itself, incorporate all factors required for fire hazard or fire risk assessment of the materials, products,
or assemblies under actual fire conditions.
1.6 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these
tests.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. For specific warning statements, see 12.2.1, 12.4.1.8, 18.1.317.1.3, 25.424.4, and Note 1918.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at
Commercial Power Frequencies
D150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation
D257 Test Methods for DC Resistance or Conductance of Insulating Materials
D374 Test Methods for Thickness of Solid Electrical Insulation (Metric) D0374_D0374M
D412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension
D471 Test Method for Rubber Property—Effect of Liquids
D543 Practices for Evaluating the Resistance of Plastics to Chemical Reagents
D638 Test Method for Tensile Properties of Plastics
D1711 Terminology Relating to Electrical Insulation
D1868 Test Method for Detection and Measurement of Partial Discharge (Corona) Pulses in Evaluation of Insulation Systems
D2303 Test Methods for Liquid-Contaminant, Inclined-Plane Tracking and Erosion of Insulating Materials
D2307 Test Method for Thermal Endurance of Film-Insulated Round Magnet Wire
D2865 Practice for Calibration of Standards and Equipment for Electrical Insulating Materials Testing
D3183 Practice for Rubber—Preparation of Pieces for Test Purposes from Products
D3636 Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
D3638 Test Method for Comparative Tracking Index of Electrical Insulating Materials
D5032 Practice for Maintaining Constant Relative Humidity by Means of Aqueous Glycerin Solutions
D5374 Test Methods for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
D3032 − 21a
D5423 Specification for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation
D6054 Practice for Conditioning Electrical Insulating Materials for Testing (Withdrawn 2012)
D8354 Test Method for Flammability of Electrical Insulating Materials Intended for Wires or Cables When Burning in a Vertical
Configuration
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 IEEE Standards:
IEEE 98 Guide for the Preparation of Test Procedures for the Thermal Evaluation of Electrical Insulating Materials
IEEE 101 Statistical Analysis of Thermal Life Test Data
2.3 Federal Standard:
PPP-T-45C Federal Specification for Tape, Gummed; Paper, Reinforced and Plain, for Sealing and Securing (PPP-T-45C)
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in these test methods, refer to Terminology D1711.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 capacitance unbalance (of a pair in a shielded cable), n—the ratio, expressed as a percentage, of the difference in
capacitance between each of two insulated conductors and the shield, to the capacitance between that conductor pair.
3.2.1.1 Discussion—
Capacitance unbalance is also called coefficient of asymmetry or capacitance asymmetry, and is expressed in percent unbalance.
3.2.2 cold bend test—a test in which a specimen is slowly wrapped around a mandrel of a specified diameter after conditioning
at a specified low temperature to determine that the primary insulation, primary jacket, overall jacket and any other layer of the
wire or cable specimen maintains sufficient flexibility to withstand such bending at that low temperature without evidence of
cracking.
3.2.3 relative thermal endurance—the comparison of the thermal endurance (as described by their Arrhenius plots) of two or more
insulated wires designed for the same specific use; this usually implies the same size of conductor, but the insulation is of the
thickness required for the particular use of each insulation.
3.2.4 strip force—force required to remove a specified length of insulation from an insulated wire specimen as determined by a
specified test procedure.
3.2.5 surface resistance, n—see Terminology D1711.
3.2.5.1 Discussion—
For a fixed electrode separation, the measured surface resistance of a given hookup wire decreases as the diameter increases.
3.2.6 temperature index, n—see Terminology D1711.
3.2.6.1 Discussion—
For hookup wire, the symbol TI is used for temperature index and the preferred use of the TI symbol implies a time of 20 000 h
obtained by analysis of aging data in which extrapolation is limited to no more than 25 °C below the lowest aging temperature.
(See also Section 1413.)
3.2.7 thermal end point curve, n—a graphical representation of a thermal end point at a specified aging temperature in which the
value of a property of a material, or a simple combination of materials, is measured at room temperature and the values plotted
as a function of time.
3.2.8 thermal end point time, n—the time necessary for a specific property of a material, or a simple combination of materials,
to degrade to a defined end point when aged at a specified temperature.
The last approved version of this historical standard is referenced on www.astm.org.
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., Piscataway, NJ 08854-4141, http://www.ieee.org.
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
D3032 − 21a
3.2.9 thermal endurance, n—see Terminology D1711.
3.2.9.1 Discussion—
The stability of hookup wire insulation is estimated from changes in the results of voltage withstand tests on hookup wire
specimens that have been heat aged, cooled to room temperature, flexed over a mandrel, immersed in salt water, and subjected to
a specific applied voltage.
3.2.10 voltage withstand (proof-voltage) test—the application of a specified voltage for a specified time to a specified configuration
of the insulation. Results are expressed as “pass” or “fail.”
4. Sampling
4.1 Refer to the material specification for sampling plan covering specific types of hookup wire insulations.
4.2 Use Practice D3636 as a guide if the material specification does not include a sampling plan.
D3032 − 21a
5. Dielectric Breakdown Voltage
5.1 Significance and Use:
5.1.1 A detailed statement of significance is given in Appendix X1 of Test Method D149.
5.2 Apparatus:
5.2.1 Use the electrical apparatus described in Test Method D149 for this test.test method.
5.3 Test Specimens:
5.3.1 The test specimen shall consist of insulated wire 610 mm (24 in.) in length, or of the length required for the environmental
exposure. Remove the insulation for a distance of 25 mm (1 in.) at each end and twist the ends together.
5.4 Procedure:
5.4.1 Immerse the test specimen to within 152 mm (6 in.) of the twisted ends in the water bath containing 5 % sodium chloride
(NaCl) and 0.05 to 0.10 % wetting agent.
6,7
NOTE 1—Triton X-100 has been found satisfactory for this test method.
5.4.2 Use the water solution as the ground electrode, and apply the voltage to the twisted end of the conductor.
5.4.3 Raise the voltage from zero at a rate of 500 V/s until the specimen fails. If a flashover between the water solution and the
twisted ends of the wire occurs, discard the specimen without retesting. Select longer specimens so that the distance between the
water solution and the ends of the wire is sufficient to prevent flashover.
5.5 Report:
5.5.1 Report the following information:
5.5.1.1 Description of the specimen,
5.5.1.2 Voltage at which breakdown occurred,
5.5.1.3 Description of any previous environmental exposure given to the specimen before testing, and
5.5.1.4 Conditions under which the test was run.
6. Insulation Resistance
6.1 Significance and Use:
6.1.1 In high impedance circuits, insulation resistance is functionally important. In some cases, changes in insulation resistance
indicates deterioration of other properties. Insulation resistance is also useful for quality control.
NOTE 2—The term “insulation resistance” is a standard term used in the hookup wire industry to designate the resistance of a specified length of insulated
wire, normally expressed as Ω-1000 ft. This is not a true insulation resistance since a resistance for a known length can be calculated and, also, the tests
are conducted in a manner to eliminate surface conduction. The value obtained in this type of measurement is actually a volume resistance, but will be
referred to here as insulation resistance to avoid confusion in the hookup wire industry.
Triton X-100 is a trademark of The Dow Chemical Company, Midlands, Michigan, http://www.dow.com.
Triton X-100 is a trademark of The Dow Chemical Company, Midlands, Michigan, http://www.dow.com. The The sole source of supply of the apparatus Triton X-100
known to the committee at this time is The Dow Chemical Company. If you are aware of alternative suppliers, please provide this information to ASTM International
Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.
D3032 − 21a
6.2 Apparatus:
6.2.1 Battery Jar, or other insulated vessel, large enough to immerse the specimen, filled with water containing 0.05 to 0.10 %
wetting agent. The water bath shall serve as one electrode.
6.2.2 Use apparatus described in Test Methods D257 for the resistance measurement.
6.3 Test Specimens:
6.3.1 The test specimen shall consist of a 8.3 m (or 26-ft) length of the insulated wire. Remove the insulation for a distance of
25 mm (1 in.) at each end and twist the ends together.
6.4 Procedure:
6.4.1 Immerse the specimen to within 152 mm (6 in.) of the twisted ends in the water bath, which is maintained at 23 6 5 °C (73
6 9 °F). Make an initial resistance measurement between the conductor and the water bath for the purpose of detecting nontypical
values. Discard any specimen with a gross defect (that is, having an insulation resistance less than 1 × 10 Ω between the conductor
and the water bath) and replace it with another specimen.
6.4.2 After 4 h, remeasure the resistance between the conductor and the water bath. Make the measurement at 500 (610 %) d-c
V, after an electrification time of 1 min, unless otherwise specified.
6.5 Calculation:
6.5.1 Calculate the insulation resistance as Ω·1000 ft as follows:
insulation resistance, Ω2 1000 ft 5 ~R 3L!/1000 (1)
where:
R = measured resistance, Ω, and
L = immersed length, 25 ft.
6.5.2 Calculate the insulation resistance as Ω-1000 m as follows:
insulation resistance, Ω2 1000 m5 R 3L' /1000 (2)
~ !
where:
L' = immersed length, 8 m.
NOTE 3—Do not express insulation resistance as Ω·m since this unit describes resistivity. It must be used as Ω for some unit of length.
6.6 Report:
6.6.1 Report the following information:
6.6.1.1 Description of the specimen,
6.6.1.2 Immersed length of the specimen,
6.6.1.3 Applied voltage,
6.6.1.4 Time of electrification,
6.6.1.5 Immersion time,
6.6.1.6 Measured resistance,
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6.6.1.7 The insulation resistance of the specimen calculated in Ω -1000 ft (or in Ω-1000 m), and
6.6.1.8 Number of specimens discarded.
7. Surface Resistance
7.1 Significance and Use:
7.1.1 At high humidities, surface conduction is responsible for the largest part of the leakage current in service (for example, at
the terminations of bundled hookup wires).
7.1.2 Additional statements on the significance of surface resistance can be found are contained in Test Methods D257.
7.2 Apparatus:
7.2.1 Test Chamber—A suitable test chamber can be made from a vessel fitted with a cover through which leads have been sealed.
The leads can be made from sealed will provide a suitable test chamber. An appropriate material for the leads is
polytetrafluoroethylene (PTFE)-insulated wire, sealed with paraffin wax or silicone grease as they pass through the cover. The use
of PTFE-insulated feed-through bushings can also be used in place of the wires is acceptable (Fig. 1).
7.2.2 As an alternative method, it is acceptable to use a paraffin wax collar can be fitted to the top of a glass vessel and tin-coated
size 1.02 mm (AWG No. 18) solid copper wires can bewires, which are sealed through the paraffin wax. A glass cover can then
be used is appropriate to seal the top of the test chamber (Fig. 2).
7.2.3 Use the test instruments described in Test Methods D257 for the resistance measurement.
7.2.4 The electrical resistance of the chamber, measured between the lead wires under the conditions given in 7.3 with no
specimens in place, shall be greater than 10 Ω.
FIG. 1 Typical Surface Resistance Test Chamber Using Feed-through Bushings
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FIG. 2 Typical Surface Resistance Test Chamber Using Paraffin Wax Collar
7.3 Test Specimens:
7.3.1 Measure five specimens.
7.3.2 The specimens shall consist of 152 mm (6-in.) lengths of finished wire, cleaned in accordance with the procedure
recommended by the manufacturer. Handle the specimens subsequently with maximum care, preferably with clean lint-free gloves
to avoid even the slightest contamination, including direct contact with the fingers. Provide each cleaned specimen near its center
with two electrodes spaced 25.4 6 0.1 mm (1.0 6 0.005 in.) (1.0 6 0.005 in.) apart between their nearest edges. Each electrode
shall be approximately 13 mm ( ⁄2 in.) wide, and shall consist of conductive silver paint painted around the circumference of the
specimen. Make electrical connection to the dry electrodes by wrapping several turns of fine tin-coated copper wire (0.361 mm
(AWG No. 27) or finer) around the electrode, leaving a free end of the fine wire of sufficient length for connecting to the electrical
lead wires inside the test chamber.
D3032 − 21a
7.4 Conditioning:
7.4.1 Measure the surface resistance after an exposure time of 96 h before removing the specimens from the test chamber.
7.4.2 Maintain the conditions in the test chamber within 62 °C of a temperature selected in the range from 18 to 27 °C, and within
62 % relative humidity of a relative humidity selected in the range from 90 to 96 % relative humidity.
7.4.3 The Maintain the relative humidity can be maintained over an aqueous glycerin solution described in Practice D5032.
NOTE 4—The allowable temperature variation for a given solution must be kept within the necessary range to maintain the relative humidity in the
chamber to the required limits.
7.5 Procedure:
7.5.1 After the conditioning period stated in 7.3, measure the resistance between the electrodes after an electrification time of 1
min at 500 (610 %) dc V.
NOTE 5—In some test methods the measured resistance is multiplied by the outside diameter of the insulation. The It is important that the values so
calculated should not be confused with the measured values nor with the true surface resistivity of the specimen.
7.6 Report:
7.6.1 Report the following information:
7.6.1.1 Description of the specimen,
7.6.1.2 Diameter of the specimen,
7.6.1.3 Test conditions (temperature and relative humidity),
7.6.1.4 Applied voltage, and
7.6.1.5 Measured surface resistance.
8. Voltage Withstand Test
8.1 Significance and Use:
8.1.1 This test method is useful as a screening test for eliminating specimens unsuitable for further testing. It can also be used s
also an acceptable method to determine whether exposure to environmental test conditions has reduced the breakdown strength
below some prescribed level.
8.2 Apparatus:
8.2.1 Use the electrical apparatus described in Test Method D149 for this test.test method.
8.2.2 Water Bath, containing 5 % sodium chloride (NaCl) and 0.5 to 0.10 % wetting agent.
8.2.3 The sensitivity of the test equipment shall be such that a fault is indicated when one half of the specified test voltage is
applied to the conductor of a length of 0.644 mm (AWG No. 22) stranded insulated wire whose other end, with the insulation cut
flush with the conductor, is inserted 6.4 mm ( ⁄4 in.) into the test solution as far from the ground electrode as the specimen to be
tested. Add more NaCl, if necessary, to the solution to meet these conditions. Fault-indicating equipment is described in Test
Method D149.
8.3 Test Specimens:
D3032 − 21a
8.3.1 The test specimen shall consist of insulated wire 610 mm (24 in.) in length, or of the length required for environmental
exposure. Remove the insulation for a distance of 25 mm (1 in.) at each end and twist the ends together.
8.3.2 Replace any specimen having an initial gross flaw (that is, having an insulation-resistance less than 1 × 10 Ω between the
conductor and the solution) before exposure to environmental conditioning.
8.4 Procedure:
8.4.1 Immerse the test specimen to within 51 mm (2 in.) of the twisted ends in the water solution described in 8.2.2.
8.4.2 Measure the resistance between the conductor and the water solution at 500 (610 %) dc V to detect gross flaws (8.3.2). Use
the apparatus described in Test Methods D257 for the resistance measurement.
NOTE 6—This screening test is performed before environmental exposure and is not repeated after the exposure.
8.4.3 After a 4-h soak, apply the voltage between the twisted ends of the conductor and the grounded water, increasing from zero
to the specified value at a rate of 500 V/s. Hold the voltage on the specimen for 1 min, or for the time required in the applicable
specification.
8.5 Report:
8.5.1 Report the following information:
8.5.1.1 Description of the specimen,
8.5.1.2 Electrification time and voltage,
8.5.1.3 Description of the environmental exposure given the specimen before test,
8.5.1.4 Whether or not the specimen withstood the required voltage for the specified time,
8.5.1.5 Time for failure in case failure occurs, and
8.5.1.6 Number of specimens discarded.
9. Capacitance of Shielded, Single-conductor Hookup Cable
9.1 Significance and Use:
9.1.1 Capacitance per unit length is useful for quality control and is sometimes required for electronic circuit design purposes.
9.1.2 Additional statements on the significance of capacitance can be are found in Test Methods D150.
9.2 Apparatus:
9.2.1 Use the apparatus described in Test Methods D150 for this test method.
9.3 Test Specimens:
9.3.1 The specimen shall consist of a piece of shielded hookup cable approximately 3 m (10 ft) in length.
9.3.2 Remove the jacket, if any, for a distance of 25 mm (1 in.) from one end of the specimen and unbraid the shield for this
distance. Remove the insulation from the conductor for a distance of 13 mm ( ⁄2 in.). Twist the unbraided shield conductors together
for connection to the measuring instrument and to prevent slippage of the shield on the insulation. A piece of tape over the shield
can also be usedis an appropriate means to prevent slippage.
D3032 − 21a
9.3.3 Terminate the opposite end of the specimen by cutting all parts of the specimen flush and perpendicular to the axis. Take
care to maintain concentricity of the specimen where it is cut. Use tape around the shield of an unjacketed specimen to prevent
slippage as long as the tape does not come in contact with the insulation or the conductor.
9.3.4 As an alternative method, prepare both ends of the specimen can be prepared in accordance with 9.3.2. When this is done,
twist the conductors from both ends of the specimen together for connection to the measuring instrument. The shields canIt is
acceptable for the shields to also be twisted together.
9.3.5 Use the distance in which the shield is in contact with the insulation as the effective length of the specimen.
9.4 Procedure:
9.4.1 Connect the specimen to the measuring instrument and measure the capacitance. Subtract the capacitance of the terminals
from the measured capacitance value (Note 7).
NOTE 7—Detailed instructions for making the measurements needed to obtain the capacitance and for making any necessary corrections due to the
measuring circuit are given in the instruction books supplied with commercial equipment.
9.5 Report:
9.5.1 Report the following information:
9.5.1.1 Description of the specimen,
9.5.1.2 Effective length of the specimen,
9.5.1.3 Frequency at which the measurement was made,
9.5.1.4 Temperature and relative humidity at which the measurement was made,
9.5.1.5 Measured capacitance, and
9.5.1.6 Capacitance of the specimen calculated in capacitance per ft (picofarad per ft) or capacitance per m (picofarad per m).
10. Capacitance and Capacitance Unbalance of Shielded Two-conductor Hookup Cable
10.1 Significance and Use:
10.1.1 Capacitance per unit length and capacitance unbalance are useful for quality control, and sometimes required for electronic
circuit design purposes.
10.2 Apparatus:
10.2.1 Use the electrical apparatus described in Test Methods D150 for this test method.
10.3 Test Specimens:
10.3.1 Prepare the specimen in accordance with 9.3, except that the insulation at one end shall be removed from both conductors
for a distance of 13 mm ( ⁄2 in.).
10.4 Procedure:
10.4.1 Designate one conductor as No. 1, the other conductor as No. 2, and the shield as No. 3.
10.4.2 The shield will be connected to one terminal of the measuring instrument for all three measurements needed to determine
the capacitance of this type of specimen.
D3032 − 21a
10.4.3 Measure the capacitance between conductor No. 2 at one terminal of the measuring instrument and No. 1 and No. 3 at the
other terminal (Note 7). This capacitance value is C .
a
10.4.4 Measure the capacitance between conductor No. 1 at one terminal and No. 2 and No. 3 at the other terminal. This
capacitance value is C .
b
10.4.5 Measure the capacitance between conductors No. 1 and No. 2 at one terminal and No. 3 at the other terminal. This value
of capacitance is C .
c
10.4.6 Measure the length of lay of the twisted pair after the shield has been removed. The lay of the helically wound insulated
conductors is the axial length of one turn of the helix.
10.5 Calculation:
10.5.1 Calculate the capacitance between the two conductors, C, as follows:
C 5 2 C 1C 2 C /4 2 C 2 C /4 C (3)
@~ ~ ! ! # @~ ! #
a b c a b c
NOTE 8—The second term of this equation is frequently neglected when the difference between C and C is small.
a b
10.5.2 Calculate the percent capacitance unbalance as follows:
capacitance unbalance,%5 C 2 C /C 3100 (4)
@~ a b! #
10.6 Report:
10.6.1 Report the following information:
10.6.1.1 Description of the specimen,
10.6.1.2 Effective length of the specimen,
10.6.1.3 Frequency at which the measurements were made,
10.6.1.4 Temperature and relative humidity at which the measurements were made,
10.6.1.5 Capacitance measured in 10.4.3, C ,
a
10.6.1.6 Capacitance measured in 10.4.4, C ,
b
10.6.1.7 Capacitance measured in 10.4.5, C ,
c
10.6.1.8 Capacitance calculated in 10.5.1,
10.6.1.9 Capacitance between the two conductors, picofarad per ft (capacitance per ft) or picofarad per m (capacitance per m),
10.6.1.10 Length of lay of the twisted pair after the shield has been removed in metres or inches, and
NOTE 9—Lay is sometimes expressed in twists per m or twists per ft.
10.6.1.11 Capacitance unbalance calculated in 10.5.2.
11. Capacitance of Unshielded Twisted Pair Hookup Wire
11.1 Significance and Use:
11.1.1 Capacitance per unit length is useful for quality control and is sometimes required for electronic circuit design purposes.
D3032 − 21a
11.2 Apparatus:
11.2.1 Use the electrical apparatus described in Test Methods D150 for this test method.
11.3 Test Specimens:
11.3.1 The specimen shall consist of a piece of twisted pair hookup wire approximately 3 m (10 ft) in length.
11.3.2 Remove the jacket, if any, for a distance of 25 mm (1 in.), or tape the wires together 1 in. back from one end of the twisted
pair. Remove 13 mm ( ⁄2 in.) of the insulation from both conductors.
11.3.3 If the sample is not jacketed, tape the other end of the specimen to prevent the wires from untwisting during measurement.
11.3.4 The length that the two wires are in contact will be used as the effective specimen length (Fig. 3).
11.4 Procedure:
11.4.1 Suspend the uncoiled specimen at least 0.9 m (3 ft) away from possible ground planes, such as work benches, table tops,
floors, etc. Any Use any insulating material can be used to hang the specimen in the appropriate position.
11.4.2 Connect the specimen to the measuring instrument and measure the capacitance. Subtract the capacitance of the terminals
from the measured capacitance value (Note 6).
11.4.3 Measure the length of lay of the twisted pair. The lay of the helically wound insulated conductor is the axial length of one
turn of the helix.
NOTE 10—The capacitance of twisted pair hookup wire is dependent on the length of lay. Higher capacitance values will be obtained on specimens of
the same material with shorter lengths of lay.
11.5 Report:
11.5.1 Report the following information:
11.5.1.1 Description of the specimen,
11.5.1.2 Effective length of the specimen,
11.5.1.3 Frequency at which the measurements were made,
11.5.1.4 Temperature and relative humidity at which the measurements were made,
11.5.1.5 Measured capacitance,
11.5.1.6 Capacitance of the specimen calculated, picofarads per ft (capacitance per ft) or picofarads per m (capacitance per m),
and
in. mm
⁄2 13
FIG. 3 Effective Specimen Length
D3032 − 21a
11.5.1.7 Length of lay of the twisted pair in inches or metres (Note 10).
12. Capacitance and Dissipation Factor of Hookup Wire Insulation by Mercury U-Tube Method
12.1 Significance and Use:
12.1.1 Capacitance per unit length and dissipation factor are useful for quality control and are sometimes required for electronic
circuit design purposes. The capacitance is also needed to calculate the permittivity (dielectric constant) of an insulating material.
12.1.2 Additional statements on the significance of capacitance and dissipation factor can be found in Test Methods D150.
12.2 Apparatus:
12.2.1 A suitable mercury U-tube electrode, as shown in Fig. 4. (Warning—Mercury metal vapor poisoning has long been
recognized as a hazard in industry. The maximum exposure limits are set by the American Conference of Governmental Industrial
Hygienist. The concentration of mercury vapor over spills from broken thermometers, barometers, or other instruments using
mercury can easily exceed these exposure limits. Mercury, being a liquid and quite heavy, will disintegrate into small droplets and
seep into cracks and crevices in the floor. The use of a commercially available emergency spill kit is recommended whenever a
spill occurs. The increased area of exposure adds significantly to the mercury vapor concentration in the air. Mercury vapor
concentration is easily monitored using commercially available sniffers. Spot checks should be made periodically around
operations where mercury is exposed to the atmosphere. Thorough checks should be made after spills.)
12.2.2 Use apparatus described in Test Methods D150.
12.3 Reagents:
12.3.1 Hydrochloric Acid (5+5).
12.3.2 Sodium Carbonate Solution.
12.4 Preparation of Apparatus:
12.4.1 Cleaning the U-Tube—To assure low resistance contact between the steel U-tube and the mercury, clean the U-tube using
the procedure given in 12.4.1.1 – 12.4.1.6, as follows:
12.4.1.1 Degrease the U-tube with toluene.
12.4.1.2 Wash with cleanser and brush.
12.4.1.3 Rinse with water.
12.4.1.4 Etch for 15 min with HCl (5+5).
12.4.1.5 Neutralize with Na CO solution.
2 3
12.4.1.6 Rinse with hot distilled water.
12.4.1.7 Fill with mercury as soon as possible after 12.4.1.6.
12.4.1.8 There is a health hazard present due to the toxicity of mercury vapor (see 12.2.1). Take suitable precautions during use.
Cap the ends of the U-tube when they are not in use. Take care to remove and appropriately dispose of mercury that adheres to
the wire as it is removed from test.
12.5 Calibration of U-Tube:
D3032 − 21a
12.5.1 Determine the length of the mercury in the U-tube by passing a small diameter wire or thin plastic line, that has been
suitably marked off for length, through the U-tube.
12.5.2 Mark off one of the glass tubes on the top of the U-tube in 6 mm ( ⁄4-in.) intervals from the mercury fill line so that the
length of specimens of different diameters can be measured.
12.6 Test Specimens:
12.6.1 The specimen shall consist of a piece of hookup wire of sufficient length to pass through the mercury U-tube and permit
joining the ends together.
12.7 Procedure:
12.7.1 Cap off one end of the specimen to prevent mercury from entering the conductor when it is inserted in the U-tube.
12.7.2 Insert the specimen in the U-tube.
NOTE 11—A thin plastic line has been found useful for pulling the specimen through the mercury U-tube. The line is reinserted as the specimen is removed.
12.7.3 Remove the insulation for a distance of 25 mm (1 in.) from each end of the specimen and twist the free ends of the
conductor together.
12.7.4 Connect the measuring instrument between the twisted ends of the specimen and the copper wire frame soldered to the
U-tube.
12.7.5 Measure the capacitance and dissipation factor of the specimen (see Note 6).
12.7.6 Record the effective length (the length of the specimen in contact with the mercury) of the specimen obtained from the
marks on the U-tube (see 12.4).
12.8 Report:
12.8.1 Report the following information:
12.8.1.1 Description of the specimen,
12.8.1.2 Effective length of the specimen,
12.8.1.3 Frequency at which the measurement was made,
12.8.1.4 Temperature and relative humidity at which the measurement was made,
12.8.1.5 Measured capacitance,
12.8.1.6 Capacitance of the specimen calculated in picofarad per m or picofarad per ft,
12.8.1.7 Dissipation factor of the specimen, and
12.8.1.8 Date, laboratory, and person making the measurement.
12. Insulation-continuity Proof Tests
12.1 Scope:
12.1.1 Insulation-continuity of hookup wire is tested by one of the following methods:
D3032 − 21a
12.1.1.1 Test Method A, Repeated-impulse Method—See 13.312.3.
12.1.1.2 Test Method B, 3000-Hz Sinusoidal-voltage Method—See 13.812.8.
12.1.2 These test methods are intended to apply primarily to the final inspection of wire for the purpose of finding and eliminating
defects prior to shipment or before use.
12.1.3 These test methods are also applicable to in-process testing to eliminate defects at an early stage of manufacture (that is,
for wire for use in multiple-conductor cables or jacketed constructions).
12.2 Significance and Use:
12.2.1 In the manufacture of hookup wire, it is desirable to have long continuous lengths. Therefore, bare wire, splices, and other
defects usually are not removed until the final stages of production. The insulation-continuity proof test serves as a 100 % screening
test to locate and permit the removal of all such defects either as an in-process procedure or during the final spooling operation,
whichever is applicable.
12.2.2 This test method is used as a manufacturing control test, as an acceptance test immediately prior to final packaging by the
producer, or as an incoming inspection by the user. In the case of its use as an acceptance test by a user, reach an agreement between
the producer and the user as to which proof test method is mutually acceptable, and specify that method in the applicable product
or purchase specification.
12.2.3 Possible damage in handling, degradation caused by repeated testing (each voltage test has the potential to lower the ability
of the wire to withstand subsequent voltage tests), and variations in test parameters will separately or in combination produce
differences that make the comparison of results between the producer and the user difficult.
12.2.4 The insulation-continuity proof test is superior to a water-immersion test in that defects can are able to be found and the
bad sections are able to be removed during the spooling operation without damaging good insulation. Because the water bath is
eliminated, the possibility of contamination of the insulated conductor is avoided.
12.3 Apparatus, Test Method A—Repeated-impulse Method:
8,9
NOTE 11—The Model IT-25 Impulse Test Calibration Set is for performing the single-shot test as well as for checking compliance with the requirements
for capacitance tolerance and failure sensitivity.
12.3.1 Electrode—The electrode consists of a bead chain construction that will give intimate metallic contact with the wire
⁄2 in. greater
insulation surface. The chain must be suspended in a U- or V-shaped trough having a width approximately 40 mm or 1
than the diameter of the largest size of wire that is tested. The chain must have a length appreciably greater than the depth of the
enclosure so that the beads will droop below the wire under test. The electrode assembly consists of an array of approximately 1.6
mm or ⁄16 in. diameter stainless steel bead chains suspended approximately 2.0 mm or 0.08 in. apart perpendicular to the direction
of wire movement (wire line) and spaced approximately 2.5 mm or 0.10 in. apart along the wire line. The electrode length must
be chosen so that at the speed being used, the wire shall be subjected to no less than three nor more than 100 pulses at any given
point. Only one electrode will be connected to the power supply transformer. The electrode must be kept free of water and foreign
matter; it must be provided with an earth grounded metal screen or equivalent guards to provide protection for the operating
personnel. Broken chains must be promptly replaced as required.
12.3.2 Power Supply—Use any impulse generator that meets the requirements of Section 1312.
12.3.2.1 Test Impulse—The waveform of the voltage applied to the electrode head shall consist of a negative pulse, the peak
magnitude of which shall be specified for the wire under test, followed by a damped oscillation. The peak impulse voltage shall
be stipulated in the applicable material specification. The rise time of the negative impulse wave from zero magnitude to 90 % of
American Conference of Governmental Industrial Hygienists, Building D-7, 6500 Glenway Ave., Cincinnati, OH 45211.The Model IT-25 Impulse Test Calibration Set
is a trademark of The Clinton Instrument Co., Clinton, CT, www.clintoninstrument.com.
The sole source of supply of the apparatus Model IT-25 Impulse Test Calibration Set known to the committee at this time is The Clinton Instrument Co. If you are aware
of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend.
D3032 − 21a
the specified peak voltage shall be not more than 75 μs. The peak value of the first positive overshoot and of the subsequent damped
oscillations shall be smaller than the initial negative pulse. The time during which the absolute magnitude of each voltage pulse
and accompanying damped oscillation (positive and negative) remains at a value of 80 % or greater of the specified peak voltage
shall be 20 to 100 μs. The pulse repetition rate shall be 200 to 250 pulses/s. Except for the final peak voltage adjustment (13.612.6)
conformity with these impulse test parameters shall be determined with no capacitive load impressed on the electrode.
12.3.2.2 Capacitive Tolerance—The tolerance of the equipment to change in capacitive load shall be such that the peak output
voltage shall be reduced by not more than 12 % in the event of an increase of the capacitive load, between electrode and ground,
from an initial load of 4.9 to 9.8 pF/cm (12.5 to 25 pF ⁄in.) of electrode length.
12.3.2.3 Instrument Voltmeter—A peak-reading voltmeter shall be provided, indicating continuously the potential of the electrode.
The voltmeter shall have a minimum accuracy of 63 % at the specified impulse potential, after calibration as specified in 13.412.4.
12.3.2.4 Failure Detection Circuit—There shall be a failure detection circuit to give a visual or audible indication, or both, of
insulation failure. In addition, de-energize the electrode head and stop the drive mechanism. The detection circuit shall be
sufficiently sensitive to indicate a fault at 75 % of the specified test voltage when the electrode is arced to ground through a 20 kΩ
resistor and shall be capable of detecting a fault that lasts for the duration of only one impulse.
12.4 Calibration—Calibrate the instrument voltmeter periodically (see Practice D2865) by comparison with an external standard
voltmeter having an accuracy of 62 % of the reading and capable of detecting the peak potential at the electrode head, with or
without auxiliary circuitry. In performing the calibration, connect the standard voltmeter to the electrode head directly or through
a calibrated attenuator circuit. Adjust the impulse generator until the reading on the standard voltmeter is the specified potential,
at which point the reading on the instrument voltmeter shall be observed and recorded. Repeat this calibration for each peak
potential at which it is intended to operate the equipment. An alternative procedure is by means of a calibrated oscilloscope
connected to the electrode through a suitable attenuator. The peak magnitude of the negative impulse canis then be read directly
readable from the waveform display. Conformance to the other waveform parameters specified in 13.3.2.112.3.2.1 shall be verified
from the oscilloscope.
12.5 Test Specimens—The test specimens consist of continuous lengths of hookup wire.
12.6 Procedure—Thread the wire through the electrode and ground the conductor at one, or preferably both, ends. Energize the
electrode to the specified peak potential and, after final adjustment of the voltage with the wire in the electrode head, pass the wire
from the pay-off spool through the electrode onto the take-up spool. The speed of passage of the wire through the electrode shall
be such that, after start-up, the wire is subjected to not less than three nor more than 100 pulses at any given point. Cut out, or
mark for later removal, all sections of wire that cause the detector to trip, along with at least 50 mm (2 in.) of wire on each side
of the failure. Locate the point of failure by passing the wire back through the head. If the detector does not trip again it can be
assumed is likely that the indication was false. Make every effort to test the entire length, including ends of the wire when stringing
up new lengths, in accordance with this procedure. Remove all ends or other portions of the wire not so tested. When testing wire
in process, or when specified in contract or order, dielectric failures, untested portions of wire, or portions that have been exposed
to fewer or more than the specified number of pulses are marked by stripping the insulation or by any other suitable method of
marking as specified in the contract in lieuinstead of being cut out of the wire.
12.7 Report—If required in sales to customers the producer shall certify that 100 % of wire supplied has been tested in accordance
with Section 1312 of these test methods.
12.8 Apparatus, Test Method B—3000-Hz Sinusoidal-voltage Method:
12.8.1 Electrode—The electrode consists of a bead chain construction that will give intimate metallic contact with the wire
insulation surface. The ch
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