ASTM F2321-23

Standard Specification for Flexible and Rigid Insulated Temporary By-Pass Jumpers

ABSTRACT
These specifications provides the manufacture and testing, as well as individual design, electrical, mechanical, and workmanship requirements for a system of flexible insulated temporary bypass jumpers used on energized power lines and equipment. These specifications for a system of bypass jumpers are covered in four parts as follows: clamps for bypass jumpers; ferrules for bypass jumpers; cable for bypass jumpers; and bypass jumpers (complete assembly with clamps, ferrules, and cable). The use and maintenance of these equipments are not addressed in these specifications.
SCOPE
1.1 This specification covers the manufacture and testing of flexible insulated temporary By-Pass jumpers (By-Pass jumpers) used on energized power lines and equipment.  
1.2 It is common practice for the user of this protective equipment to prepare complete instructions and safety regulations to govern in detail the correct and safe use of such equipment. Also see 4.2.  
1.3 The use and maintenance of this equipment are beyond the scope of this specification.  
1.4 This specification for a system of By-Pass jumpers is covered in four parts as follows:    
Title  
Sections  
Clamps for By-Pass Jumpers  
5 – 17  
Ferrules for By-Pass Jumpers  
18 – 31  
Cable for By-Pass Jumpers  
32 – 40  
By-Pass Jumpers (complete assembly
with clamps, ferrules, and cable)  
41 – 55  
1.5 Each of the four parts is an entity of itself, but is listed as a part of the system for completeness and clarification.  
1.6 The values stated in SI units are to be regarded as the standard. See IEEE/ASTM SI 10.  
1.7 The following precautionary caveat pertains only to the test method portions, Sections 13, 26, 48, and 55 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.  
1.8 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-Jan-2023
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: F18 - Electrical Protective Equipment for Workers
• Drafting Committee: F18.45 - Mechanical Apparatus

Relations

• Refers: ASTM E8/E8M-24 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM B33-10(2020)e1 - Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes
• Effective Date: 01-Jan-2020
• Refers: ASTM B172-17 - Standard Specification for Rope-Lay-Stranded Copper Conductors Having Bunch-Stranded Members, for Electrical Conductors
• Effective Date: 01-Apr-2017
• Refers: ASTM B173-17 - Standard Specification for Rope-Lay-Stranded Copper Conductors Having Concentric-Stranded Members, for Electrical Conductors
• Effective Date: 01-Apr-2017
• Refers: ASTM E8/E8M-16 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 15-Jul-2016
• Refers: ASTM B173-10(2015) - Standard Specification for Rope-Lay-Stranded Copper Conductors Having Concentric-Stranded Members, for Electrical Conductors
• Effective Date: 01-Apr-2015
• Refers: ASTM B172-10(2015) - Standard Specification for Rope-Lay-Stranded Copper Conductors Having Bunch-Stranded Members, for Electrical Conductors
• Effective Date: 01-Apr-2015
• Refers: ASTM E8/E8M-15 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Feb-2015
• Refers: ASTM D2802-14 - Standard Specification for Ozone-Resistant Ethylene-Alkene Polymer Insulation<brk/> for Wire and Cable (Withdrawn 2020)
• Effective Date: 01-Nov-2014
• Refers: ASTM B33-10(2014) - Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes
• Effective Date: 01-Sep-2014
• Refers: ASTM E8/E8M-13 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM E8/E8M-11 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Dec-2011
• Refers: ASTM D2802-03(2010) - Standard Specification for Ozone-Resistant Ethylene-Alkene Polymer Insulation for Wire and Cable
• Effective Date: 01-Oct-2010
• Refers: ASTM B33-10 - Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes
• Effective Date: 01-Apr-2010
• Refers: ASTM B173-10 - Standard Specification for Rope-Lay-Stranded Copper Conductors Having Concentric-Stranded Members, for Electrical Conductors
• Effective Date: 01-Apr-2010

Overview

ASTM F2321-23 is the internationally recognized standard specification for flexible and rigid insulated temporary by-pass jumpers. Issued by ASTM International, this standard details the manufacturing, testing, and design requirements for by-pass jumper systems used on energized power lines and equipment. The by-pass jumper system covered by this specification includes clamps, ferrules, cables, and the complete assembly. The standard does not cover the safe use or maintenance practices for this equipment, which should be governed by individual organizations' safety regulations.

Flexible and rigid insulated temporary by-pass jumpers are critical for ensuring continuity of electric circuits during maintenance or repair activities, preventing interruptions while providing enhanced safety for personnel working on energized lines.

Key Topics

• Scope and Purpose: Defines electrical, mechanical, and workmanship requirements for by-pass jumper systems, outlining the specific criteria for each component (clamps, ferrules, and cables) and complete assembled jumpers.
• Component Specifications:
  • Clamps: Requirements for both insulated and uninsulated clamps, with detailed classifications for jaw style and installation methods.
  • Ferrules: Standards for copper and aluminum ferrules, including types, sizes, and installation compatibility.
  • Cables: Specifications for conductor materials, insulation types (mostly ethylene-propylene rubber), voltage ratings, size ranges, and identification markings.
• Testing and Inspection:
  • Minimum performance requirements for electrical and mechanical testing, including torque strength, continuous current rating, and insulation proof tests.
  • Sampling protocols, testing procedures, and criteria for acceptance and rejection of production lots.
• Workmanship: Standards for finish and appearance, ensuring components are free from structural defects that may adversely impact safety or performance.
• Product Identification: Marking and packaging requirements for traceability and protection during shipping.

Applications

By following ASTM F2321-23, utilities and electrical contractors can ensure that flexible and rigid insulated temporary by-pass jumpers meet critical quality and performance criteria for use on energized lines. Key applications include:

• Live-line Maintenance: Maintain circuit continuity when conductors or equipment must be opened or isolated, reducing power interruptions.
• Electrical Distribution and Transmission: Used during upgrades, repairs, or emergency bypass situations in substations and along distribution lines.
• Safety Enhancement: Provide temporary insulation to protect personnel from accidental brush contact while working near energized circuits.
• Standardization for Purchasing: Enables purchasers and manufacturers to specify jumper components and assemblies with exact characteristics (e.g., clamp style, cable size, voltage rating) for reliable, repeatable use.

It is important to note that ASTM F2321-23 is not a use or maintenance manual. Organizations should supplement this standard with robust internal safety procedures for the deployment and care of by-pass jumper systems.

Related Standards

ASTM F2321-23 references and aligns with several widely recognized standards for materials and electrical systems, such as:

• ASTM B33, B172, B173: Specifications for copper wire and conductors used in electrical applications.
• NEMA WC 8: Ethylene-propylene rubber insulated wire and cable, relevant for cable materials.
• ANSI C84.1: Voltage ratings for power systems and equipment.
• ANSI C119.4: Electrical connectors' standards.
• IEEE/ASTM SI 10: Metric practice for units and measurements.
• ASTM F819: Terminology relating to electrical protective equipment for workers.

These references ensure compatibility and consistency across a broad spectrum of electrical system components and facilitate global acceptance of the standard.

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Keywords: ASTM F2321-23, insulated by-pass jumpers, flexible jumpers, rigid jumpers, electrical safety, live-line maintenance, temporary by-pass, power line equipment, ASTM standard, ferrules, clamps, cable insulation, electrical testing, mechanical testing, product marking, utility safety 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: F2321 − 23
Standard Specification for
Flexible and Rigid Insulated Temporary By-Pass Jumpers
This standard is issued under the fixed designation F2321; 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 2. Referenced Documents
1.1 This specification covers the manufacture and testing of
2.1 ASTM Standards:
flexible insulated temporary By-Pass jumpers (By-Pass jump-
B33 Specification for Tin-Coated Soft or Annealed Copper
ers) used on energized power lines and equipment.
Wire for Electrical Purposes
B172 Specification for Rope-Lay-Stranded Copper Conduc-
1.2 It is common practice for the user of this protective
tors Having Bunch-Stranded Members, for Electrical Con-
equipment to prepare complete instructions and safety regula-
ductors
tions to govern in detail the correct and safe use of such
B173 Specification for Rope-Lay-Stranded Copper Conduc-
equipment. Also see 4.2.
tors Having Concentric-Stranded Members, for Electrical
1.3 The use and maintenance of this equipment are beyond
Conductors
the scope of this specification.
D2768 Specification for General-Purpose Ethylene-
Propylene Rubber Jacket for Wire and Cable (Withdrawn
1.4 This specification for a system of By-Pass jumpers is
2007)
covered in four parts as follows:
D2770 Specification for Ozone-Resisting Ethylene-
Title Sections
Clamps for By-Pass Jumpers 5 – 17
Propylene Rubber Integral Insulation and Jacket for Wire
Ferrules for By-Pass Jumpers 18 – 31
and Cable (Withdrawn 2007)
Cable for By-Pass Jumpers 32 – 40
D2802 Specification for Ozone-Resistant Ethylene-Alkene
By-Pass Jumpers (complete assembly 41 – 55
with clamps, ferrules, and cable)
Polymer Insulation for Wire and Cable (Withdrawn
2020)
1.5 Each of the four parts is an entity of itself, but is listed
D2865 Practice for Calibration of Standards and Equipment
as a part of the system for completeness and clarification.
for Electrical Insulating Materials Testing
1.6 The values stated in SI units are to be regarded as the
E8/E8M Test Methods for Tension Testing of Metallic Ma-
standard. See IEEE/ASTM SI 10.
terials
1.7 The following precautionary caveat pertains only to the
F819 Terminology Relating to Electrical Protective Equip-
test method portions, Sections 13, 26, 48, and 55 of this ment for Workers
specification. This standard does not purport to address all of
IEEE/ASTM SI 10 American National Standard for Metric
the safety concerns, if any, associated with its use. It is the
Practice
responsibility of the user of this standard to establish appro-
2.2 ANSI Standards:
priate safety, health, and environmental practices and deter-
ANSI C39.5 Safety Requirements for Electrical and Elec-
mine the applicability of regulatory limitations prior to use.
tronic Measuring and Controlling Instruments
1.8 This international standard was developed in accor-
ANSI C84.1 Voltage Ratings for Electric Power Systems and
dance with internationally recognized principles on standard-
Equipment (60 Hz)
ization established in the Decision on Principles for the
ANSI C119.4 American National Standard for Electrical
Development of International Standards, Guides and Recom-
Connectors
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
This specification is under the jurisdiction of ASTM Committee F18 on Standards volume information, refer to the standard’s Document Summary page on
Electrical Protective Equipment for Workers and is the direct responsibility of the ASTM website.
Subcommittee F18.45 on Mechanical Apparatus. The last approved version of this historical standard is referenced on www.ast-
Current edition approved Feb. 1, 2023. Published March 2023. Originally m.org.
approved in 2003. Last previous edition approved in 2020 as F2321 – 14 (2020). Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
DOI: 10.1520/F2321-23. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2321 − 23
2.3 NEMA Standard: during work operations. By-Pass jumpers are insulated to
WC 8 Ethylene-Propylene-Rubber Insulated Wire and Cable temporarily protect personnel from brush or accidental contact
for the Transmission and Distribution of Electrical Energy only; therefore, when authorizing their use, a margin of safety
(formerly ICEA S-68-516) should be provided between the maximum voltage used on,
and the proof-test voltage at which they are tested. The
3. Terminology
relationship between proof-test voltage and the maximum
voltage at which By-Pass jumpers are used is shown in Table
3.1 Definitions:
1. Warning—Portions of these devices (clamps and ferrules)
3.1.1 flexible and rigid insulated temporary By-Pass
are not insulated and offer no protection from accidental
jumpers—devices designed and used to keep electric supply
contact.
circuits effectively continuous (electrically bridged) for short
periods of time at work locations when conductors or equip-
CLAMPS FOR BY-PASS JUMPERS
ment may otherwise be opened or made electrically discon-
tinuous during work operations.
5. Scope
3.1.1.1 Discussion—The devices are normally installed,
5.1 This specification covers clamps used in the assembly of
used, and removed as part of a protective insulating system
By-Pass jumpers.
composed of insulating covers and/or observances of required
minimum safe approach distances for workers.
6. Classification
3.1.2 voltage, normal design—a nominal value consistent
6.1 Clamps are furnished in, but not limited to, two styles
with the latest revision of ANSI C84.1, assigned to the circuit
according to their function and method of installation.
or system for the purpose of conveniently designating its
6.1.1 Style I—Clamps equipped with insulated handles for
voltage class.
installation on energized conductors with rubber gloves. See
3.1.3 voltage, maximum use—the ac voltage (rms) classifi-
Fig. 1.
cation of the protective equipment that designates the maxi-
6.1.1.1 Insulated handles may be either clear or opaque.
mum nominal design voltage of the energized system that may
6.1.1.2 Insulating materials used in this specification in-
be safely worked. The nominal design voltage is equal to
clude thermo-set plastic, elastomers, elastomer compounds,
phase-to-phase voltage on multiphase circuits.
thermoplastic polymers or any combination, regardless of
3.1.3.1 Discussion—If there is no multiphase exposure in a
origin.
system area, and the voltage exposure is limited to phase
6.1.2 Style II—Clamps equipped with provisions for instal-
(polarity on dc systems) to ground potential, the phase (polarity
lation on energized conductors with live line tools. See Fig. 2
on dc systems) to ground potential shall be considered to be the
and Fig. 3.
nominal design voltage.
6.1.2.1 Clamps are furnished according to mechanical
3.1.3.2 Discussion—If electrical equipment and devices are
strength and current rating. See Table 2.
insulated or isolated, or both, such that the multiphase exposure
6.2 Clamps are furnished in two classes according to the
on a grounded wye circuit is removed, then the nominal design
characteristics of the main contact jaws.
voltage may be considered as the phase-to-ground voltage on
6.2.1 Class A—Clamp jaws with smooth contact surfaces.
that circuit.
6.2.2 Class B—Clamp jaws with serrations, crosshatching
NOTE 1—The work practices and methods associated with removing
or other means intended to abrade or bite through corrosion
multiphase exposures at any given work site are not addressed in this
products on the surface of the conductor being clamped.
specification.
3.2 For definitions of other terms, refer to Terminology
7. Sizes
F819.
7.1 Clamp size is the combination of the main contact and
cable size ranges as listed by the manufacturers.
4. Significance and Use
4.1 This specification covers the minimum electrical and
8. Ordering Information
physical properties designated by the manufacturer and the
8.1 Orders for clamps under this specification shall include
detailed procedures by which such properties are to be deter-
this ASTM designation and the following information:
mined. The purchaser may at his option perform or have
8.1.1 Quantity,
performed any of these tests in order to verify the manufactur-
8.1.2 Name (By-Pass Jumper Clamp),
er’s designation. Claims for failure to meet the specification are
subject to verification by the manufacturer.
TABLE 1 Proof Test/Use Voltage Relationship
4.2 By-Pass jumpers are devices designed and used to keep
Maximum AC Proof DC Proof
electrical circuits effectively continuous (electrically bridged)
Voltage
Use Voltage Test Voltage Test Voltage
for short periods of time at work locations when conductors or Rating
(rms) V (rms) V (avg) V
equipment may otherwise be opened or made discontinuous
15 kV 15 000 20 000 50 000
25 kV 25 000 30 000 60 000
35 kV 35 000 40 000 70 000
Available from National Electrical Manufacturers Association (NEMA), 1300 69 kV 69 000 74 000
N. 17th St., Suite 1847, Rosslyn, VA 22209.
F2321 − 23
FIG. 3 Style II Duck Bill Shape Clamp
FIG. 1 Style I Clamp
TABLE 2 Clamp Torque Strength, min—Style II Clamps
Cable Continuous
A
Yield Ultimate
Size Current
(AWG) A, rms, 60 Hz N-m (lbf in.) N-m (lbf in.)
#2 200A 32 (280) 37 (330)
1/0 250A 32 (280) 37 (330)
2/0 300A 32 (280) 37 (330)
4/0 400A 37 (330) 45 (400)
A
Yield shall mean no permanent deformation such that the clamp cannot be
reused throughout its entire range of application.
TABLE 3 Material Properties
Copper Base Alloy Aluminum Base Alloy
Tensile Strength, min. 207 Mpa (30 000 psi) 207 Mpa (30 000 psi)
Yield Strength, min. 90 Mpa (13 000 psi) 138 Mpa (20 000 psi)
Elongation, min 6 % 3 %
FIG. 2 Style II “C” Shape Clamp
NOTE 2—Style II clamps are uninsulated and do not require confor-
8.1.3 Main contact size ranges, conductor descriptions, and
mance with the electrical requirements of Table 1.
type of materials which are to be clamped,
10.2.1 Clamps shall accept hand assembly of all cables
8.1.4 Cable size, material, and description by which clamps
fitted with compatible ferrules as rated per Table 2.
are to be assembled,
10.2.2 Main contacts shall accept and clamp all conductors
8.1.5 Style (see 6.1),
according to the manufacturer’s recommendation.
8.1.6 Class (see 6.2), and
10.2.3 Style II clamps shall have the following properties:
8.1.7 Clamps for By-Pass jumpers, at the customer’s
10.2.3.1 In the event the clamp is over-torqued during
request, shall meet ANSI C119.4.
installation, normal fracture shall be such that the attached
cable remains under control by being retained with the live line
9. Materials
tool. Clamps with an ultimate torque strength exceeding
9.1 Current carrying parts of copper base or aluminum base
45 N-m (400 lbf in.) are exempt from this provision.
alloy shall meet the material properties shown in Table 3 and in
10.2.3.2 Cable termination shall include a cable support or
accordance with Test Methods E8/E8M.
shall be made to accept a cable supporting ferrule compatible
with the clamp. This support shall secure the entire cable over
10. Electrical and Mechanical Properties
the jacket and is provided in addition to the electrical connec-
10.1 Materials used shall meet the requirements of 9.1.
tion to the strand.
10.2 Electrical and mechanical properties shall conform to 10.2.3.3 Clamps shall be compatible with clamp sticks and
the requirements prescribed in Tables 1-3 and with the follow- shall fit securely inside the 13 mm ( ⁄2-in.) wide slot in the head
ing: of the stick.
F2321 − 23
10.2.4 Main contacts shall accept and clamp all conductors warmest spot on clamp and on the metal strand at the midpoint
or structural members in accordance with the manufacturer’s of an attached cable, which is a minimum of 1.5 m (5 ft) in
rating. length. Maintain current until thermal stability is achieved.
Thermal stability shall be achieved when the temperature rise
11. Workmanship, Finish, and Appearance
of a minimum of three consecutive readings taken at five-
11.1 Components shall be free of structural porosity, fins, minute intervals does not differ by more than 61 °C (1.8 °F)
sharp edges, splits, cracks and other defects that affect handling for each thermocouple being used. The maximum temperature
or performance. of the clamp shall be lower than the midpoint temperature of
the attached cable.
11.2 All parts shall be formed, machined, and assembled
with sufficient accuracy for smooth operation by hand, and
14. Inspection and Product Testing
shall be free of excessive looseness to the extent detrimental to
repeated applications at the recommended installing torque.
14.1 The clamps shall be inspected and tested as follows:
11.3 Class A (smooth jaw) clamps shall have smooth contact 14.1.1 Verification of the main contact and cable capacities
surfaces free of burrs, fins, or other protuberances that would are in accordance with 10.2.2 and 10.2.3.
impair performance.
14.1.2 Visual inspection and hand operation shall be done to
verify workmanship, finish, and appearance, which shall be in
11.4 Class B (serrated jaw) clamps shall have longitudinally
accordance with Section 11.
level surface, that, with clamp movement as specified by the
14.1.3 Torque test on a test sample shall be in accordance
manufacturer, will provide a cleaning effect on the surface of
with 13.2.
the conductor.
11.5 Slag grinding marks, depressions, and other surface
15. Acceptance, Rejection and Rehearing
irregularities that do not affect strength, performance, or
handling are not cause for rejection.
15.1 At the option of the purchaser, a production lot may be
subjected to the following:
12. Sampling
15.1.1 Inspection in accordance with 14.1 for operation,
12.1 A product model represents a manufacturer’s design
main contact range, workmanship, and appearance. Individual
specification standard according to which the production lot is
clamps that do not conform may be rejected.
manufactured.
15.2 Material that fails to conform to the requirements of
12.2 A production lot shall consist of all clamps of one
this specification may be rejected. Rejection should be reported
production model produced at one time.
to the producer or supplier promptly and in writing. In case of
12.3 A test sample shall consist of two specimens for each
dissatisfaction with the results of the test, the producer or
different test specified. Specimens are selected at random and
supplier may make claim for a rehearing.
shall pass the inspection requirements of Section 14. When a
15.3 If electrical testing, mechanical testing, or both, are
failure occurs in one specimen from the first sample, a second
required by a user prior to acceptance, it shall be done in
sample from the same lot shall be selected and tested. If the
accordance with this specification for any part or for all of the
second sample (two specimens) passes, the lot shall be ac-
tests to be performed.
cepted. If one specimen from the second sample fails, the lot
shall be rejected.
16. Certification
13. Design Tests
16.1 When specified in the purchase order or contract, a
13.1 The design tests that follow shall be made on test
manufacturer’s or supplier’s certification shall be furnished to
samples of each product model to verify that the requirements
the purchaser that the clamps were manufactured, sampled,
of this specification are met.
tested, and inspected in accordance with this specification and
have been found to meet the requirements. When specified in
13.2 Mechanical Torque Strength:
the purchase order or contract, a report of design test shall be
13.2.1 Install the clamp on the main conductor of the
furnished.
minimum and maximum size for which the clamp is rated and
apply torsion force to the main screw. Force may be applied to
17. Packaging and Package Marking
other devices designed to secure the clamp on the conductor.
13.2.2 Measure torque by a torque wrench that indicates
17.1 Clamps shall be marked with the name or logo of the
torque directly or by other manner easily convertible.
manufacturer, identity number, and date code to indicate year
13.2.3 The main conductor is defined as the material(s) on
of manufacture.
which the clamp is rated to be used.
17.2 A packing list indicating manufacturer’s product num-
13.2.4 Yield and ultimate strength shall equal or exceed the
bers and quantities of each different clamp shall be provided
values shown in Table 2.
with each shipment.
13.3 Continuous Current Rating:
13.3.1 Test the clamp at the continuous current level for 17.3 Each shipment shall be packaged to provide protection
which it is rated. The temperature shall be measured at the of the contents appropriate for the mode of transportation.
F2321 − 23
CABLE FERRULES FOR BY-PASS JUMPERS
18. Scope
18.1 This specification covers ferrules used with By-Pass
jumpers.
18.2 Two styles of ferrules are available and are designated
as shrouded or unshrouded.
19. Classification
19.1 Ferrules are furnished in four types as follows:
19.1.1 Type I—Compression ferrule is cylindrical and made
for installation on cable stranding by compression. FIG. 5 Type IV Threaded Stud-Shrouded Compression Ferrule
19.1.2 Type III—Plain stud-shrouded compression ferrule
has a stepped bore that accepts entire cable and jacket. (See
Fig. 4.)
19.1.3 Type IV—Threaded stud shrouded compression fer-
rule has a stepped bore that accepts entire cable over jacket and
has male threads at forward end. (See Fig. 5.)
19.1.4 Type VI—Threaded stud compression ferrule has
male threads at forward end. (See Fig. 6.)
20. Size
20.1 Ferrule size is the combination of cable capacity, stud
description, and size after installation of cable.
21. Ordering Information
21.1 Orders for ferrules under this specification should
include this ASTM designation and the following information: FIG. 6 Type VI Threaded Stud Compression Ferrule
21.1.1 Quantity,
21.1.2 Name (By-Pass Jumper Cable Ferrules),
21.1.3 Description, and material of clamp in which ferrule is
23. Electrical and Physical Properties
to be installed,
21.1.4 Cable description to include conductor size, material
23.1 Closed end ferrules utilizing the compression method
and outside diameter of insulation on which ferrule is to be
of cable installation may have a 3 mm (0.125 in.) minimum
installed, and
diameter inspection vent hole through one side at the bottom of
21.1.5 Type (see 19.1).
the (cable) bore. This applies to Types III, IV, and VI.
23.2 Ferrules shall accept cables for which they are rated
22. Materials
without alteration of strands, and can be assembled by hand
22.1 Current carrying parts of copper base or aluminum
with compatible clamps.
base ferrules shall meet the following requirements:
22.1.1 Copper Base Alloy—Copper content 60 % minimum.
24. Workmanship, Finish and Appearance
22.1.2 Aluminum Base Alloy—Aluminum content 90 %
24.1 Components shall be free of structural defects that
minimum.
affect installation, assembly or performance.
24.2 Minor surface irregularities that do not affect strength
or performance are not cause for rejection.
25. Sampling
25.1 A product model represents a manufacturer’s design
specification according to which the production lot is manu-
factured.
25.2 A production lot shall consist of all ferrules of one
product model produced at one time.
25.3 A test sample shall consist of two specimens selected at
random from a production lot for each different test specified.
When a failure occurs in one specimen from the first sample, a
FIG. 4 Type III Plain Stud-Shrouded Compression Ferrule second sample shall be selected from the same lot and tested.
F2321 − 23
If the second sample (two specimens) passes, the lot shall be 30. Product Marking
acceptable. If one specimen from the second sample fails, the
30.1 Ferrules shall be marked with the manufacturer’s
lot shall be rejected.
identity code.
26. Design Tests
31. Packaging
26.1 Design tests shall be made on test samples of each
31.1 Each shipment shall be packaged to provide protection
product model to verify that the requirements of the specifica-
of the contents appropriate for the mode of transportation.
tion are met.
CABLE FOR BY-PASS JUMPERS
26.2 Continuous Current Rating:
26.2.1 Test the ferrules at the continuous current rating. The
32. Scope
temperature shall be measured at the warmest spot on the
32.1 This specification covers the material, construction,
clamp and on the metal strand at the midpoint of an attached
and testing of the cable used in the manufacture of By-Pass
cable, which is a minimum of 1.5 m (5 ft) in length. The
jumpers.
maximum temperature of the ferrule shall be lower than the
midpoint temperature of the maximum size copper cable for
33. Classification
which the ferrule is rated.
33.1 By-Pass jumper cables have flexible stranded copper
27. Inspection
conductors, insulated with ethylene-propylene rubber (EPR). A
heavy duty polyethylene jacket can be applied directly over the
27.1 Visual and gauging inspection shall verify
insulation for additional mechanical protection. Cables covered
workmanship, finish, and appearance in accordance with Sec-
under this specification are designated as Jacketed and Non-
tion 24.
Jacketed.
28. Acceptance, Rejection, and Rehearing
33.2 Flexible portions of By-Pass jumpers
...

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: F2321 − 14 (Reapproved 2020) F2321 − 23
Standard Specification for
Flexible and Rigid Insulated Temporary By-Pass Jumpers
This standard is issued under the fixed designation F2321; 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 These specifications coverThis specification covers the manufacture and testing of flexible insulated temporary By-Pass
jumpers (By-Pass jumpers) used on energized power lines and equipment.
1.2 It is common practice for the user of this protective equipment to prepare complete instructions and safety regulations to
govern in detail the correct and safe use of such equipment. Also see 4.2.
1.3 The use and maintenance of this equipment are beyond the scope of these specifications.this specification.
1.4 These specificationsThis specification for a system of By-Pass jumpers is covered in four parts as follows:
Title Sections
Clamps for By-Pass Jumpers 5 – 17
Ferrules for By-Pass Jumpers 18 – 31
Cable for By-Pass Jumpers 32 – 40
By-Pass Jumpers (complete assembly 41 – 55
with clamps, ferrules, and cable)
1.5 Each of the four parts is an entity of itself, but is listed as a part of the system for completeness and clarification.
1.6 The values stated in SI units are to be regarded as the standard. See IEEE/ASTM SI 10.
1.7 The following precautionary caveat pertains only to the test method portions, Sections 13, 26, 48, and 55 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.
1.8 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.
This specification is under the jurisdiction of ASTM Committee F18 on Electrical Protective Equipment for Workers and is the direct responsibility of Subcommittee
F18.45 on Mechanical Apparatus.
Current edition approved Feb. 15, 2020Feb. 1, 2023. Published March 2020March 2023. Originally approved in 2003. Last previous edition approved in 20142020 as
F2321F2321 – 14 (2020).–14. DOI: 10.1520/F2321-14R20.10.1520/F2321-23.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2321 − 23
2. Referenced Documents
2.1 ASTM Standards:
B33 Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes
B172 Specification for Rope-Lay-Stranded Copper Conductors Having Bunch-Stranded Members, for Electrical Conductors
B173 Specification for Rope-Lay-Stranded Copper Conductors Having Concentric-Stranded Members, for Electrical Conduc-
tors
D2768 Specification for General-Purpose Ethylene-Propylene Rubber Jacket for Wire and Cable (Withdrawn 2007)
D2770 Specification for Ozone-Resisting Ethylene-Propylene Rubber Integral Insulation and Jacket for Wire and Cable
(Withdrawn 2007)
D2802 Specification for Ozone-Resistant Ethylene-Alkene Polymer Insulation for Wire and Cable (Withdrawn 2020)
D2865 Practice for Calibration of Standards and Equipment for Electrical Insulating Materials Testing
E8E8/E8M Test Methods for Tension Testing of Metallic Materials [Metric] E0008_E0008M
F819 Terminology Relating to Electrical Protective Equipment for Workers
IEEE/ASTM SI 10 American National Standard for Metric Practice
2.2 ANSI Standards:
ANSI C39.5 Safety Requirements for Electrical and Electronic Measuring and Controlling Instruments
ANSI C84.1 Voltage Ratings for Electric Power Systems and Equipment (60 Hz)
ANSI C119.4 American National Standard for Electrical Connectors
2.3 NEMA Standard:
WC 8 Ethylene-Propylene-Rubber Insulated Wire and Cable for the Transmission and Distribution of Electrical Energy
(formerly ICEA S-68-516)
3. Terminology
3.1 Definitions:
3.1.1 flexible and rigid insulated temporary By-Pass jumpers—devices designed and used to keep electric supply circuits
effectively continuous (electrically bridged) for short periods of time at work locations when conductors or equipment may
otherwise be opened or made electrically discontinuous during work operations.
3.1.1.1 Discussion—
The devices are normally installed, used, and removed as part of a protective insulating system composed of insulating covers
and/or observances of required minimum safe approach distances for workers.
3.1.2 voltage, normal design—a nominal value consistent with the latest revision of ANSI C84.1, assigned to the circuit or system
for the purpose of conveniently designating its voltage class.
3.1.3 voltage, maximum use—the ac voltage (rms) classification of the protective equipment that designates the maximum nominal
design voltage of the energized system that may be safely worked. The nominal design voltage is equal to phase-to-phase voltage
on multiphase circuits.
3.1.3.1 Discussion—
If there is no multiphase exposure in a system area, and the voltage exposure is limited to phase (polarity on dc systems) to ground
potential, the phase (polarity on dc systems) to ground potential shall be considered to be the nominal design voltage.
3.1.3.2 Discussion—
If electrical equipment and devices are insulated or isolated, or both, such that the multiphase exposure on a grounded wye circuit
is removed, then the nominal design voltage may be considered as the phase-to-ground voltage on that circuit.
NOTE 1—The work practices and methods associated with removing multiphase exposures at any given work site are not addressed in this specification.
3.2 For definitions of other terms, refer to Terminology F819.
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.
The last approved version of this historical standard is referenced on www.astm.org.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.
Available from National Electrical Manufacturers Association (NEMA), 1300 N. 17th St., Suite 1847, Rosslyn, VA 22209.
F2321 − 23
4. Significance and Use
4.1 These specifications coverThis specification covers the minimum electrical and physical properties designated by the
manufacturer and the detailed procedures by which such properties are to be determined. The purchaser may at his option perform
or have performed any of these tests in order to verify the manufacturer’s designation. Claims for failure to meet the specification
are subject to verification by the manufacturer.
4.2 By-Pass jumpers are devices designed and used to keep electrical circuits effectively continuous (electrically bridged) for short
periods of time at work locations when conductors or equipment may otherwise be opened or made discontinuous during work
operations. By-Pass jumpers are insulated to temporarily protect personnel from brush or accidental contact only; therefore, when
authorizing their use, a margin of safety should be provided between the maximum voltage used on, and the proof-test voltage at
which they are tested. The relationship between proof-test voltage and the maximum voltage at which By-Pass jumpers are used
is shown in Table 1. Warning—WarningPortions—Portions of these devices (clamps and ferrules) are not insulated and offer no
protection from accidental contact.
CLAMPS FOR BY-PASS JUMPERS
5. Scope
5.1 This specification covers clamps used in the assembly of By-Pass jumpers.
6. Classification
6.1 Clamps are furnished in, but not limited to, two styles according to their function and method of installation.
6.1.1 Style I—Clamps equipped with insulated handles for installation on energized conductors with rubber gloves. See Fig. 1.
6.1.1.1 Insulated handles may be either clear or opaque.
6.1.1.2 Insulating materials used in this specification include thermo-set plastic, elastomers, elastomer compounds, thermoplastic
polymers or any combination, regardless of origin.
6.1.2 Style II—Clamps equipped with provisions for installation on energized conductors with live line tools. See Fig. 2 and Fig.
3.
6.1.2.1 Clamps are furnished according to mechanical strength and current rating. See Table 2.
6.2 Clamps are furnished in two classes according to the characteristics of the main contact jaws.
6.2.1 Class A—Clamp jaws with smooth contact surfaces.
6.2.2 Class B—Clamp jaws with serrations, crosshatching or other means intended to abrade or bite through corrosion products
on the surface of the conductor being clamped.
7. Sizes
7.1 Clamp size is the combination of the main contact and cable size ranges as listed by the manufacturers.
TABLE 1 Proof Test/Use Voltage Relationship
Maximum AC Proof DC Proof
Voltage
Use Voltage Test Voltage Test Voltage
Rating
(rms) V (rms) V (avg) V
15 kV 15 000 20 000 50 000
25 kV 25 000 30 000 60 000
35 kV 35 000 40 000 70 000
69 kV 69 000 74 000
F2321 − 23
FIG. 1 Style I Clamp
FIG. 2 Style II “C” Shape Clamp
8. Ordering Information
8.1 Orders for clamps under this specification shall include this ASTM designation and the following information:
8.1.1 Quantity,
8.1.2 Name (By-Pass Jumper Clamp),
8.1.3 Main contact size ranges, conductor descriptions, and type of materials which are to be clamped,
8.1.4 Cable size, material, and description by which clamps are to be assembled,
8.1.5 Style (see 6.1),
8.1.6 Class (see 6.2), and
8.1.7 Clamps for By-Pass jumpers, at the customer’s request, shall meet ANSI C119.4.
F2321 − 23
FIG. 3 Style II Duck Bill Shape Clamp
TABLE 2 Clamp Torque Strength, min—Style II Clamps
Cable Continuous
A
Yield Ultimate
Size Current
(AWG) A, rms, 60 Hz N-m (lbf in.) N-m (lbf in.)
#2 200A 32 (280) 37 (330)
1/0 250A 32 (280) 37 (330)
2/0 300A 32 (280) 37 (330)
4/0 400A 37 (330) 45 (400)
A
Yield shall mean no permanent deformation such that the clamp cannot be
reused throughout its entire range of application.
9. Materials
9.1 Current carrying parts of copper base or aluminum base alloy shall meet the material properties shown in Table 3 and in
accordance with Test Methods E8E8/E8M.
10. Electrical and Mechanical Properties
10.1 Materials used shall meet the requirements of 9.1.
10.2 Electrical and mechanical properties shall conform to the requirements prescribed in Tables 1-3 and with the following:
NOTE 2—Style II clamps are uninsulated and do not require conformance with the electrical requirements of Table 1.
10.2.1 Clamps shall accept hand assembly of all cables fitted with compatible ferrules as rated per Table 2.
10.2.2 Main contacts shall accept and clamp all conductors according to the manufacturer’s recommendation.
10.2.3 Style II clamps shall have the following properties:
TABLE 3 Material Properties
Copper Base Alloy Aluminum Base Alloy
Tensile Strength, min. 207 Mpa (30 000 psi) 207 Mpa (30 000 psi)
Yield Strength, min. 90 Mpa (13 000 psi) 138 Mpa (20 000 psi)
Elongation, min 6 % 3 %
F2321 − 23
10.2.3.1 In the event the clamp is over-torqued during installation, normal fracture shall be such that the attached cable remains
under control by being retained with the live line tool. Clamps with an ultimate torque strength exceeding 45 N-m (400 lbf 45 N-m
(400 lbf in.) are exempt from this provision.
10.2.3.2 Cable termination shall include a cable support or shall be made to accept a cable supporting ferrule compatible with the
clamp. This support shall secure the entire cable over the jacket and is provided in addition to the electrical connection to the strand.
10.2.3.3 Clamps shall be compatible with clamp sticks and shall fit securely inside the 13 mm ( ⁄2-in.) wide slot in the head of
the stick.
10.2.4 Main contacts shall accept and clamp all conductors or structural members in accordance with the manufacturer’s rating.
11. Workmanship, Finish, and Appearance
11.1 Components shall be free of structural porosity, fins, sharp edges, splits, cracks and other defects that affect handling or
performance.
11.2 All parts shall be formed, machined, and assembled with sufficient accuracy for smooth operation by hand, and shall be free
of excessive looseness to the extent detrimental to repeated applications at the recommended installing torque.
11.3 Class A (smooth jaw) clamps shall have smooth contact surfaces free of burrs, fins, or other protuberances that would impair
performance.
11.4 Class B (serrated jaw) clamps shall have longitudinally level surface, that, with clamp movement as specified by the
manufacturer, will provide a cleaning effect on the surface of the conductor.
11.5 Slag grinding marks, depressions, and other surface irregularities that do not affect strength, performance, or handling are not
cause for rejection.
12. Sampling
12.1 A product model represents a manufacturer’s design specification standard according to which the production lot is
manufactured.
12.2 A production lot shall consist of all clamps of one production model produced at one time.
12.3 A test sample shall consist of two specimens for each different test specified. Specimens are selected at random and shall pass
the inspection requirements of Section 14. When a failure occurs in one specimen from the first sample, a second sample from the
same lot shall be selected and tested. If the second sample (two specimens) passes, the lot shall be accepted. If one specimen from
the second sample fails, the lot shall be rejected.
13. Design Tests
13.1 The design tests that follow shall be made on test samples of each product model to verify that the requirements of this
specification are met.
13.2 Mechanical Torque Strength:
13.2.1 Install the clamp on the main conductor of the minimum and maximum size for which the clamp is rated and apply torsion
force to the main screw. Force may be applied to other devices designed to secure the clamp on the conductor.
13.2.2 Measure torque by a torque wrench that indicates torque directly or by other manner easily convertible.
13.2.3 The main conductor is defined as the material(s) on which the clamp is rated to be used.
F2321 − 23
13.2.4 Yield and ultimate strength shall equal or exceed the values shown in Table 2.
13.3 Continuous Current Rating:
13.3.1 Test the clamp at the continuous current level for which it is rated. The temperature shall be measured at the warmest spot
on clamp and on the metal strand at the midpoint of an attached cable, which is a minimum of 1.5 m (5 ft.) in length. The maximum
temperature of the clamp shall be lower than the midpoint ft) in length. Maintain current until thermal stability is achieved. Thermal
stability shall be achieved when the temperature rise of a minimum of three consecutive readings taken at five-minute intervals
does not differ by more than 61 °C (1.8 °F) for each thermocouple being used. The maximum temperature of the maximum size
copper main or tap cable for which the clamp is rated.clamp shall be lower than the midpoint temperature of the attached cable.
14. Inspection and Product Testing
14.1 The clamps shall be inspected and tested as follows:
14.1.1 Verification of the main contact and cable capacities are in accordance with 10.2.2 and 10.2.3.
14.1.2 Visual inspection and hand operation shall be done to verify workmanship, finish, and appearance, which shall be in
accordance with Section 11.
14.1.3 Torque test on a test sample shall be in accordance with 13.2.
15. Acceptance, Rejection and Rehearing
15.1 At the option of the purchaser, a production lot may be subjected to the following:
15.1.1 Inspection in accordance with 14.1 for operation, main contact range, workmanship, and appearance. Individual clamps that
do not conform may be rejected.
15.2 Material that fails to conform to the requirements of this specification may be rejected. Rejection should be reported to the
producer or supplier promptly and in writing. In case of dissatisfaction with the results of the test, the producer or supplier may
make claim for a rehearing.
15.3 If electrical testing, mechanical testing, or both, are required by a user prior to acceptance, it shall be done in accordance with
this specification for any part or for all of the tests to be performed.
16. Certification
16.1 When specified in the purchase order or contract, a manufacturer’s or supplier’s certification shall be furnished to the
purchaser that the clamps were manufactured, sampled, tested, and inspected in accordance with this specification and have been
found to meet the requirements. When specified in the purchase order or contract, a report of design test shall be furnished.
17. Packaging and Package Marking
17.1 Clamps shall be marked with the name or logo of the manufacturer, identity number, and date code to indicate year of
manufacture.
17.2 A packing list indicating manufacturer’s product numbers and quantities of each different clamp shall be provided with each
shipment.
17.3 Each shipment shall be packaged to provide protection of the contents appropriate for the mode of transportation.
F2321 − 23
CABLE FERRULES FOR BY-PASS JUMPERS
18. Scope
18.1 This specification covers ferrules used with By-Pass jumpers.
18.2 Two styles of ferrules are available and are designated as shrouded or unshrouded.
19. Classification
19.1 Ferrules are furnished in four types as follows:
19.1.1 Type I—Compression ferrule is cylindrical and made for installation on cable stranding by compression.
19.1.2 Type III—Plain stud-shrouded compression ferrule has a stepped bore that accepts entire cable and jacket. (See Fig. 4.)
19.1.3 Type IV—Threaded stud shrouded compression ferrule has a stepped bore that accepts entire cable over jacket and has male
threads at forward end. (See Fig. 5.)
19.1.4 Type VI—Threaded stud compression ferrule has male threads at forward end. (See Fig. 6.)
20. Size
20.1 Ferrule size is the combination of cable capacity, stud description, and size after installation of cable.
21. Ordering Information
21.1 Orders for ferrules under this specification should include this ASTM designation and the following information:
21.1.1 Quantity,
21.1.2 Name (By-Pass Jumper Cable Ferrules),
21.1.3 Description, and material of clamp in which ferrule is to be installed,
21.1.4 Cable description to include conductor size, material and outside diameter of insulation on which ferrule is to be installed,
and
21.1.5 Type (see 19.1).
FIG. 4 Type III Plain Stud-Shrouded Compression Ferrule
F2321 − 23
FIG. 5 Type IV Threaded Stud-Shrouded Compression Ferrule
FIG. 6 Type VI Threaded Stud Compression Ferrule
22. Materials
22.1 Current carrying parts of copper base or aluminum base ferrules shall meet the following requirements:
22.1.1 Copper Base Alloy—Copper content 60 % minimum.
22.1.2 Aluminum Base Alloy—Aluminum content 90 % minimum.
23. Electrical and Physical Properties
23.1 Closed end ferrules utilizing the compression method of cable installation may have a 3 mm (0.125 in.) minimum diameter
inspection vent hole through one side at the bottom of the (cable) bore. This applies to Types III, IV, and VI.
23.2 Ferrules shall accept cables for which they are rated without alteration of strands, and can be assembled by hand with
compatible clamps.
24. Workmanship, Finish and Appearance
24.1 Components shall be free of structural defects that affect installation, assembly or performance.
24.2 Minor surface irregularities that do not affect strength or performance are not cause for rejection.
25. Sampling
25.1 A product model represents a manufacturer’s design specification according to which the production lot is manufactured.
25.2 A production lot shall consist of all ferrules of one product model produced at one time.
F2321 − 23
25.3 A test sample shall consist of two specimens selected at random from a production lot for each different test specified. When
a failure occurs in one specimen from the first sample, a second sample shall be selected from the same lot and tested. If the second
sample (two specimens) passes, the lot shall be acceptable. If one specimen from the second sample fails, the lot shall be rejected.
26. Design Tests
26.1 Design tests shall be made on test samples of each product model to verify that the requirements of the specification are met.
26.2 Continuous Current Rating:
26.2.1 Test the ferrules at the continuous current rating. The temperature shall be measured at the warmest spot on the clamp and
on the metal strand at the midpoint of an attached cable, which is a minimum of 1.5 m (5 ft) in length. The maximum temperature
of the ferrule shall be lower than the midpoint temperature of the maximum size copper cable for which the ferrule is rated.
27. Inspection
27.1 Visual and gauging inspection shall verify workmanship, finish, and appearance in accordance with Section 2424.
28. Acceptance, Rejection, and Rehearing
28.1 At the option of the purchaser, a production lot may be subjected to the following:
28.1.1 Gauging inspection in accordance with Section 27. Individual ferrules that do not conform may be rejected.
28.1.2 A test sample may be tested for continuous current, in accordance with Table 4.
28.1.3 Failure of two specimens from two test samples, which have been properly installed according to the manufacturer’s
specifications, shall be cause for rejection of the production lot from which the samples were taken.
28.1.4 Material that fails to confor
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