ASTM D5423-23

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: D5423 − 22 D5423 − 23
Standard Specification for
Forced-Convection Laboratory Ovens for Evaluation of
Electrical Insulation
This standard is issued under the fixed designation D5423; 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 specification covers forced-convection ventilated electrically-heated ovens, operating over all or part of the temperature
range from 20 °C above the ambient temperature to 500 °C, and used for thermal endurance evaluation of electrical insulating
materials.
1.2 The specification requirements for Type I ovens are based on IEC Publication 60216-4-1, and are technically identical to it.
The requirements for Type II ovens are essentially identical to the requirements of Specification D2436. This specification and an
associated test method, D5374, have replaced Specification D2436.
1.3 While the ovens covered by this specification are intended primarily for thermal endurance evaluation, their characteristics
make them suitable for other applications as applicable.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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.
1.6 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:
D1711 Terminology Relating to Electrical Insulation
D2436 Specification for Forced-Convection Laboratory Ovens for Electrical Insulation (Withdrawn 1994)
D5374 Test Methods for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation
This specification 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 May 1, 2022Feb. 1, 2023. Published May 2022February 2023. Originally approved in 1993. Last previous edition approved in 20142022 as
D5423 – 14.D5423 – 22. DOI: 10.1520/D5423-22.10.1520/D5423-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5423 − 23
2.2 Other Document:
IEC Publication 60216-4-1 Electrical Insulating Materials—Thermal Endurance Properties—Part 4-1: Ageing Ovens—Single-
Chamber Ovens
3. Terminology
3.1 For terms related to electrical and electronic insulating materials issues refer to Terminology D1711.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 rate of ventilation, n—the number of air changes per hour in the oven chamber.
3.2.2 set temperature, n—the average of all of the measured temperatures within the oven, averaged over the period of any cyclic
temperature variation that occurs.
3.2.2.1 Discussion—
This is the actual operating temperature of the oven. In IEC 60216-4-1, this term is called the exposure temperature.
3.2.3 temperature fluctuation, n—maximum change in temperature at one point in the oven over a period of time.
3.2.3.1 Discussion—
This property depends upon the sensitivity and type (on/off or proportional) of control used and the heater mass in relation to
surface area.
3.2.4 temperature gradient, n—the maximum temperature difference at one time between any two points in the oven chamber.
3.2.4.1 Discussion—
This property depends on such factors as uniformity of heater temperature, heater distribution about the oven, and air flow patterns
within the oven. In IEC 60216-4-1, this term is called the temperature difference.
3.2.5 temperature variation, n—maximum change in temperature with time and location due to the combination of temperature
gradient and temperature fluctuation.
3.2.6 thermal lag time, n—the time required for a defined specimen to reach a specified temperature (or range of temperature).
3.2.6.1 Discussion—
This property is largely dependent upon the rate of air circulation within the oven. In IEC 60216-4-1, this term is called the “time
constant.”
4. Classification
4.1 Type I—Ovens with rate of ventilation of 5 to 20 air changes per hour.
4.2 Type II—Ovens with rate of ventilation of 100 to 200 air changes per hour.
5. Test Methods
5.1 Determine the properties specified in Section 6 using Test Methods D5374.
6. Performance Requirements
6.1 Rate of Ventilation—The rate of ventilation at 100 °C and at the maximum temperature at which the oven is used shall be:
6.1.1 For Type I ovens, 5 to 20 air changes per hour,
6.1.2 For Type II ovens, 100 to 200 air changes per hour.
NOTE 1—Past experience in the United States has been to specify 100 to 200 air changes per hour, as required for Type II ovens. However, current
international practice is to prefer the lower rate of ventilation specified for Type I ovens.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.
D5423 − 23
6.2 Set Temperature—The set temperature, measured over a five-day test period, shall not vary by more than the values given in
Table 1.
6.3 Temperature Variation—The temperature shall not exceed that given in Table 1 for any test temperature.
NOTE 2—Some test standards require closer control of temperature variation or of set temperature. In such cases, reduction of the variatio
...