ASTM D2307-21

Standard Test Method for Thermal Endurance of Film-Insulated Round Magnet Wire

SIGNIFICANCE AND USE
5.1 This test method is useful in determining the thermal endurance characteristics and thermal indices of film-insulated round magnet wire in air (see 1.3). This test method is used as a screening test before making tests of more complex systems or functional evaluation. It is also used where complete functional systems testing is not feasible.  
5.2 Experience has shown that film-insulated wire and electrical insulating varnishes or resins can affect one another during the thermal exposure process. Test Method D3251 provides indications on the thermal endurance for a combination of insulating varnish or resin and film insulated wire. It is possible that interaction between varnish or resin and film insulation will increase or decrease the relative thermal life of the varnish and film insulated wire combination compared with the life of the film insulated wire tested without varnish.  
5.3 The conductor type or the surface condition of the conductor will affect the thermal endurance of film-insulated magnet wire. This test method is used to determine the thermal endurance characteristics of film insulation on various kinds of conductors. The use of sizes other than those specified in 7.1.1 is permissible but is not recommended for determining thermal endurance characteristics.  
5.4 The temperature index determined by this test method is a nominal or relative value expressed in degrees Celsius at 20 000 h. It is to be used for comparison purposes only and is not intended to represent the temperature at which the film insulated wire could be operated.  
5.5 There are many factors that influence the results obtained with this test method. Among the more obvious are the following:  
5.5.1 Wire size and film thickness.  
5.5.2 Moisture conditions during proof voltage tests.  
5.5.3 Oven construction:
5.5.3.1 Velocity of air.
5.5.3.2 Amount of replacement air.
5.5.3.3 Elimination of products of decomposition during thermal exposure.
5.5.3.4 Oven loading....
SCOPE
1.1 This test method covers determination of the thermal endurance of film-insulated round magnet wire in air at atmospheric pressure. It is not applicable to magnet wire with fibrous insulation, such as cotton or glass.  
1.2 This test method covers the evaluation of thermal endurance by observing changes in response to ac proof voltage tests. The evaluation of thermal endurance by observing changes in other properties of magnet wire insulation requires the use of different test methods.  
1.3 It is possible that exposure of some types of film insulated wire to heat in gaseous or liquid environments in the absence of air will give thermal endurance values different from those obtained in air. Consider this possibility when interpreting the results obtained by heating in air with respect to applications where the wire will not be exposed to air in service.  
1.4 It is possible that electric stress applied for extended periods at a level exceeding or even approaching the discharge inception voltage will change significantly the thermal endurance of film insulated wires. Under such electric stress conditions, it is possible that comparisons between materials will also differ from those developed using this method.  
1.5 This test method is similar to IEC 60172. Differences exist regarding specimen preparation.  
1.6 The values stated in inch-pound units are to be regarded as the standard. The SI units in parentheses are provided for information only and are not considered standard.  
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.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in...

General Information

• Status: Published
• Publication Date: 30-Jun-2021
• ICS: 29.060.10 - Wires
• Technical Committee: D09 - Electrical and Electronic Insulating Materials
• Drafting Committee: D09.17 - Fire and Thermal Properties

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: D2307 − 21
Standard Test Method for
1
Thermal Endurance of Film-Insulated Round Magnet Wire
This standard is issued under the fixed designation D2307; 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.
1. Scope* ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This test method covers determination of the thermal
mendations issued by the World Trade Organization Technical
endurance of film-insulated round magnet wire in air at
Barriers to Trade (TBT) Committee.
atmospheric pressure. It is not applicable to magnet wire with
fibrous insulation, such as cotton or glass.
2. Referenced Documents
1.2 This test method covers the evaluation of thermal
2
2.1 ASTM Standards:
endurance by observing changes in response to ac proof
D1676 Test Methods for Film-Insulated Magnet Wire
voltage tests. The evaluation of thermal endurance by observ-
D1711 Terminology Relating to Electrical Insulation
ing changes in other properties of magnet wire insulation
D3251 Test Method for Thermal Endurance Characteristics
requires the use of different test methods.
of Electrical Insulating Varnishes Applied Over Film-
1.3 It is possible that exposure of some types of film
Insulated Magnet Wire
insulated wire to heat in gaseous or liquid environments in the
D5423 Specification for Forced-Convection Laboratory Ov-
absence of air will give thermal endurance values different
ens for Evaluation of Electrical Insulation
from those obtained in air. Consider this possibility when
2.2 Other Standards:
interpreting the results obtained by heating in air with respect
IEC 60172 Test Procedure For The Determination Of The
to applications where the wire will not be exposed to air in
3
Temperature Index Of Enamelled Winding Wires
service.
IEEE 101 Guide for the StatisticalAnalysis of Thermal Life
4
1.4 It is possible that electric stress applied for extended
Test Data
periods at a level exceeding or even approaching the discharge
inception voltage will change significantly the thermal endur-
3. Terminology
ance of film insulated wires. Under such electric stress
3.1 Definitions:
conditions, it is possible that comparisons between materials
3.1.1 temperature index, n—a number which permits com-
will also differ from those developed using this method.
parison of the temperature/time characteristics of an electrical
1.5 This test method is similar to IEC 60172. Differences
insulatingmaterial,orasimplecombinationofmaterials,based
exist regarding specimen preparation.
on the temperature in degrees Celsius which is obtained by
1.6 The values stated in inch-pound units are to be regarded extrapolating theArrhenius plot of life versus temperature to a
as the standard. The SI units in parentheses are provided for specified time, usually 20 000 h.
information only and are not considered standard.
3.1.2 thermal endurance, n—an expression for the stability
1.7 This standard does not purport to address all of the of an electrical insulating material, or a simple combination of
safety concerns, if any, associated with its use. It is the materials, when maintained at elevated temperatures for ex-
responsibility of the user of this standard to establish appro- tended periods of time.
priate safety, health, and environmental practices and deter-
3.2 Definitions of Terms Specific to This Standard:
mine the applicability of regulatory limitations prior to use.
1.8 This international standard was developed in accor-
dance with internationally recognized principles on standard-
2
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
1
This test method is under the jurisdiction of ASTM Committee D09 on the ASTM website.
3
Electrical and Electronic Insulating Materials and is the direct responsibility of Available from International Electrotechnical Commission (IEC), 3, rue de
Subcommittee D09.17 on Fire and Thermal Properties. Varembé, 1st floor, P.O. Box 131, CH-1211, Geneva 20, Switzerland, https://
Current edition approved July 1, 2021. Published August 2021. Originally www.iec.ch.
4
approved in 1964. Last previous edition approved in 2013 as D2307 – 07a (2013). Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
DOI: 10.1520/D2307-21 445 Hoes L
...

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: D2307 − 07a (Reapproved 2013) D2307 − 21
Standard Test Method for
1
Thermal Endurance of Film-Insulated Round Magnet Wire
This standard is issued under the fixed designation D2307; 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.
1. Scope*
1.1 This test method covers determination of the thermal endurance of film-insulated round magnet wire in air at atmospheric
pressure. It is not applicable to magnet wire with fibrous insulation, such as cotton or glass.
1.2 This test method covers the evaluation of thermal endurance by observing changes in response to ac proof voltage tests. The
evaluation of thermal endurance by observing changes in other properties of magnet wire insulation requires the use of different
test methods.
1.3 It is possible that exposure of some types of film insulated wire to heat in gaseous or liquid environments in the absence of
air will give thermal endurance values different from those obtained in air. Consider this possibility when interpreting the results
obtained by heating in air with respect to applications where the wire will not be exposed to air in service.
1.4 It is possible that electric stress applied for extended periods at a level exceeding or even approaching the discharge inception
voltage will change significantly the thermal endurance of film insulated wires. Under such electric stress conditions, it is possible
that comparisons between materials will also differ from those developed using this method.
1.5 This test method is similar to IEC 60172. Differences exist regarding specimen preparation.
1.6 The values stated in inch-pound units are to be regarded as the standard. The SI units in parentheses are provided for
information only.only and are not considered standard.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
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
2.1 ASTM Standards:
D1676 Test Methods for Film-Insulated Magnet Wire
1
This test method is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of Subcommittee
D09.17 on Fire and Thermal Properties.
Current edition approved April 1, 2013July 1, 2021. Published April 2013August 2021. Originally approved in 1964. Last previous edition approved in 20072013 as
D2307 – 07a.D2307 – 07a (2013). DOI: 10.1520/D2307-07AR13. 10.1520/D2307-21
2
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.
*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
1

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D2307 − 21
D1711 Terminology Relating to Electrical Insulation
D3251 Test Method for Thermal Endurance Characteristics of Electrical Insulating Varnishes Applied Over Film-Insulated
Magnet Wire
D5423 Specification for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation
2.2 Other Standards:
IEC 60172 Statistical Analysis of Thermal Life Test DataTest Procedure For The Determination Of The Temperature Index Of
3
Enamelled Winding Wires
4
IEEE 101 Guide for the Statistical Analysis of Thermal Life Test Data
3. Terminology
3.1 Definitions:
3.1.1 temperature index, n—a number which permits comparison of the temperature/time characteristics of an electrical insulating
material, or a simple combination of materials, based on the temperature in degrees Celsius which is obtained by extrapolating the
Arrhenius plot of life versus temperature to a specified time, usually 2
...