ASTM D1048-20

Standard Specification for Rubber Insulating Blankets

ABSTRACT
This specification covers the acceptance testing of insulating rubber blankets that are used for the personal protection of workers from accidental contact with live electrical conductors, apparatus, or circuits. Two types of blankets, differing in chemical and physical characteristics, are provided and are designated as: Type I, made from properly vulcanized high-grade cis-1,4-polyisoprene rubber compound of natural or synthetic origin that is non-resistant to ozone; and Type II, made of any elastomer or combination of elastomeric compounds that is resistant to ozone. Five classes of blankets, designated as Classes 0, 1, 2, 3, and 4, are assigned according to electrical protection characteristics. Styles of blankets are designated in accordance to construction characteristics, namely: Style A, blankets free of any reinforcements; and Style B, blankets incorporated with reinforcement(s). When evaluated in accordance with the test procedures detailed herein, the blankets shall adhere to the following property requirements: electrical properties such as phase-phase maximum use voltage, AC and DC proof-test voltages, AC and DC dielectric breakdown test voltages, and AC and DC clearances; and physical and chemical properties such as ozone resistance, moisture absorption, tensile strength, tension set, elongation, drape stiffness, flex stiffness, tear resistance, resistance to accelerated heat aging, and puncture resistance.
SCOPE
1.1 This specification covers acceptance testing of rubber insulating blankets for protection of workers from accidental contact with live electrical conductors, apparatus, or circuits.  
1.2 Two types of blankets are provided and are designated as Type I, not resistant to ozone, and Type II, resistant to ozone.  
1.3 Five classes of blankets, differing in electrical characteristics, are provided and are designated as Class 0, Class 1, Class 2, Class 3, and Class 4.  
1.4 Two styles of blankets, differing in construction characteristics, are provided and are designated as Style A and Style B.  
1.5 The following safety hazards caveat pertains only to the test method portion, Sections 16 – 19, of this specification: 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.

General Information

• Status: Historical
• Publication Date: 31-Jan-2020
• ICS: 29.035.20 - Plastics and rubber insulating materials
• Technical Committee: F18 - Electrical Protective Equipment for Workers
• Drafting Committee: F18.25 - Insulating Cover-Up Equipment

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D1048 −20
Standard Specification for
1
Rubber Insulating Blankets
This standard is issued under the fixed designation D1048; 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 D297Test Methods for Rubber Products—ChemicalAnaly-
sis
1.1 This specification covers acceptance testing of rubber
D412TestMethodsforVulcanizedRubberandThermoplas-
insulating blankets for protection of workers from accidental
tic Elastomers—Tension
contact with live electrical conductors, apparatus, or circuits.
D518 Test Method for Rubber Deterioration—Surface
3
1.2 Two types of blankets are provided and are designated
Cracking (Withdrawn 2007)
asTypeI,notresistanttoozone,andTypeII,resistanttoozone.
D570Test Method for Water Absorption of Plastics
D573Test Method for Rubber—Deterioration in an Air
1.3 Five classes of blankets, differing in electrical
characteristics, are provided and are designated as Class 0, Oven
D624Test Method for Tear Strength of Conventional Vul-
Class 1, Class 2, Class 3, and Class 4.
canized Rubber and Thermoplastic Elastomers
1.4 Two styles of blankets, differing in construction
D1388Test Method for Stiffness of Fabrics
characteristics, are provided and are designated as StyleAand
D2865Practice for Calibration of Standards and Equipment
Style B.
for Electrical Insulating Materials Testing
1.5 The following safety hazards caveat pertains only to the
F819Terminology Relating to Electrical Protective Equip-
testmethodportion,Sections16–19,ofthisspecification: This
ment for Workers
standard does not purport to address all of the safety concerns,
2.2 American National Standards:
if any, associated with its use. It is the responsibility of the user
4
ANSI/IEEE C 2National Electrical Safety Code
of this standard to establish appropriate safety, health, and
C84.1Electric Power Systems and Equipment—Voltage
environmental practices and determine the applicability of
5
Ratings (60 Hz)
regulatory limitations prior to use.
1.6 This international standard was developed in accor-
3. Terminology
dance with internationally recognized principles on standard-
3.1 beaded edge—a narrow border of thicker rubber which
ization established in the Decision on Principles for the
extends completely around the outer edges of the blanket.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
3.2 breakdown—the electrical discharge or arc occurring
Barriers to Trade (TBT) Committee.
betweentheelectrodesandthroughtheequipmentbeingtested.
3.3 designated person—an individual who is qualified by
2. Referenced Documents
experience or training to perform an assigned task.
2
2.1 ASTM Standards:
3.4 electrical testing facility—a location with qualified
D149Test Method for Dielectric Breakdown Voltage and
personnel,testingequipment,andproceduresfortheinspection
DielectricStrengthofSolidElectricalInsulatingMaterials
and electrical testing of electrical insulating protective equip-
at Commercial Power Frequencies
ment.
1 3.5 electrode clearance—the shortest path from the ener-
This specification is under the jurisdiction of ASTM Committee F18 on
Electrical Protective Equipment for Workers and is the direct responsibility of gized electrode to the ground electrode.
Subcommittee F18.25 on Insulating Cover-Up Equipment. This standard replaces
ANSI Standard J6.4, which is no longer available.
Current edition approved Feb. 1, 2020. Published February 2020. Originally
3
approved in 1949 as D1048–49 T. Last previous edition approved in 2019 as The last approved version of this historical standard is referenced on
D1048-14(2019). DOI: 10.1520/D1048-20. www.astm.org.
2 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org.
5
Standards volume information, refer to the standard’s Document Summary page on Available from National Electrical Manufacturers Association (NEMA), 1300
the ASTM website. N. 17th St., Suite 900, Arlington, VA 22209, http://www.nema.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D1048−20
3.6 flashover—the electrical discharge or arc occurring be- turer and the detailed procedures by which such prop
...

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: D1048 − 14 (Reapproved 2019) D1048 − 20
Standard Specification for
1
Rubber Insulating Blankets
This standard is issued under the fixed designation D1048; 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 This specification covers acceptance testing of rubber insulating blankets for protection of workers from accidental contact
with live electrical conductors, apparatus, or circuits.
1.2 Two types of blankets are provided and are designated as Type I, not resistant to ozone, and Type II, resistant to ozone.
1.3 Five classes of blankets, differing in electrical characteristics, are provided and are designated as Class 0, Class 1, Class 2,
Class 3, and Class 4.
1.4 Two styles of blankets, differing in construction characteristics, are provided and are designated as Style A and Style B.
1.5 The following safety hazards caveat pertains only to the test method portion, Sections 16 – 19, of this specification: 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
2.1 ASTM Standards:
D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at
Commercial Power Frequencies
D297 Test Methods for Rubber Products—Chemical Analysis
D412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension
3
D518 Test Method for Rubber Deterioration—Surface Cracking (Withdrawn 2007)
D570 Test Method for Water Absorption of Plastics
D573 Test Method for Rubber—Deterioration in an Air Oven
D624 Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplastic Elastomers
D1388 Test Method for Stiffness of Fabrics
D2865 Practice for Calibration of Standards and Equipment for Electrical Insulating Materials Testing
F819 Terminology Relating to Electrical Protective Equipment for Workers
2.2 American National Standards:
4
ANSI/IEEE C 2 National Electrical Safety Code
5
C84.1 Electric Power Systems and Equipment—Voltage Ratings (60 Hz)
1
This specification is under the jurisdiction of ASTM Committee F18 on Electrical Protective Equipment for Workers and is the direct responsibility of Subcommittee
F18.25 on Insulating Cover-Up Equipment. This standard replaces ANSI Standard J 6.4, which is no longer available.
Current edition approved April 1, 2019Feb. 1, 2020. Published April 2019February 2020. Originally approved in 1949 as D1048 – 49 T. Last previous edition approved
in 20142019 as D1048D1048-14(2019).-14. DOI: 10.1520/D1048-14R19.10.1520/D1048-20.
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.
3
The last approved version of this historical standard is referenced on www.astm.org.
4
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org.
5
Available from National Electrical Manufacturers Association (NEMA), 1300 N. 17th St., Suite 900, Arlington, VA 22209, http://www.nema.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D1048 − 20
3. Terminology
3.1 beaded edge—a narrow border of thicker rubber which extends completely around the outer edges of the blanket.
3.2 breakdown—the electrical discharge or arc occurring between the electrodes and through the equipment being tested.
3.3 designated person—an individual who is qualified by experience or training to perfor
...