ASTM B784-01(2006)

Standard Specification for Modified Concentric-Lay-Stranded Copper Conductors for Use in Insulated Electrical Cables

ABSTRACT
This specification covers bare modified concentric-lay-stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated electrical cables. These conductors shall be constructed with a central core consisting of not more than seven wires, surrounded by one or more layers of helically laid wires. For the purposes of this specification, conductors are classified as Class B modified, class C modified, and Class D modified. The conductors shall meet the prescribed construction requirements such as number of wires and diameter. Welds and brazes may be made in rods or in wires prior to final drawing. Welds and brazes may be made in the finished individual wires composing the conductor, but shall not be closer together than prescribed distance. Tests for the electrical properties of wires composing conductors made from soft or annealed copper wire, bare or coated, shall be made before stranding. Tests for the physical properties of these materials may be made upon the wires before stranding or upon wires removed from the complete stranded conductor.
SCOPE
1.1 This specification covers bare modified concentric-lay-stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated electrical cables. These conductors shall be constructed with a central core consisting of not more than seven wires, surrounded by one or more layers of helically laid wires.
1.2 For the purposes of this specification, conductors are classified as follows (Explanatory Note 1 and Note 2):
1.2.1 Class B Modified—Conductors to be insulated with various materials such as rubber, paper, and crosslink polyethylene.
1.2.2 Class C Modified and Class D Modified—Conductors where greater flexibility is required than is provided by Class B Modified conductors.
1.3 The values stated in inch-pound or SI units are to be regarded separately as standard. Each system shall be used independently of the other. Combining the values from the two systems may result in non- conformance with the specification. For conductor sizes designated by AWG or kcmil sizes, the requirements in SI units are numerically converted from the corresponding requirements in inch-pound units. For conductor sizes designated by AWG or kcmil, the requirements in SI units have been numerically converted from corresponding values stated or derived in inch-pound units. for conductor sizes designated by SI units only, the requirements are stated or derived in SI units.
1.3.1 For density, resitivity and temperature, the values stated in SI units are to be regarded as standard.
Note 1—The significant differences in this specification from Specification B 8 are as follows: (1) The central core is permitted to contain up to seven wires drawn into the assembly with an infinite length of lay while Specification B 8 permits only one, and (2) The construction is applicable only to stranded assemblies of 19 or more wires.

General Information

• Status: Historical
• Publication Date: 30-Sep-2006
• ICS: 29.060.20 - Cables
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.04 - Conductors of Copper and Copper Alloys

Relations

• Replaces: ASTM B784-01 - Standard Specification for Modified Concentric-Lay-Stranded Copper Conductors for Use in Insulated Electrical Cables
• Effective Date: 01-Oct-2006
• Replaced By: ASTM B784-01(2012) - Standard Specification for Modified Concentric-Lay-Stranded Copper Conductors for Use in Insulated Electrical Cables
• Effective Date: 01-Apr-2012
• Referred By: ASTM B226-11(2021) - Standard Specification for Cored, Annular, Concentric-Lay-Stranded Copper Conductors
• Effective Date: 01-Oct-2006

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: B784 – 01 (2006)
Standard Specification for
Modified Concentric-Lay-Stranded Copper Conductors for
Use in Insulated Electrical Cables
This standard is issued under the fixed designation B784; 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.
Specification B8 permits only one, and (2) The construction is applicable
1. Scope
only to stranded assemblies of 19 or more wires.
1.1 This specification covers bare modified concentric-lay-
stranded conductors made from round copper wires, either
2. Referenced Documents
uncoated or coated with tin, lead, or lead alloy for general use
2.1 The following documents of the issue in effect at the
in insulated electrical cables. These conductors shall be con-
dateofmaterialpurchaseformapartofthisspecificationtothe
structed with a central core consisting of not more than seven
extent referenced herein.
wires,surroundedbyoneormorelayersofhelicallylaidwires.
2.2 ASTM Standards:
1.2 For the purposes of this specification, conductors are
B3 Specification for Soft or Annealed Copper Wire
classified as follows (Explanatory Note 1 and Note 2):
B8 Specification for Concentric-Lay-Stranded Copper Con-
1.2.1 Class B Modified—Conductors to be insulated with
ductors, Hard, Medium-Hard, or Soft
various materials such as rubber, paper, and crosslink polyeth-
B33 Specification forTinned Soft orAnnealed CopperWire
ylene.
for Electrical Purposes
1.2.2 Class C Modified and Class D Modified—Conductors
B189 Specification for Lead-Coated and Lead-Alloy-
where greater flexibility is required than is provided by Class
Coated Soft Copper Wire for Electrical Purposes
B Modified conductors.
B263 Test Method for Determination of Cross-Sectional
1.3 The values stated in inch-pound or SI units are to be
Area of Stranded Conductors
regarded separately as standard. Each system shall be used
B354 Terminology Relating to Uninsulated Metallic Elec-
independently of the other. Combining the values from the two
trical Conductors
systems may result in non- conformance with the specification.
2.3 Other Standard:
For conductor sizes designated by AWG or kcmil sizes, the
NBS Handbook 100
requirements in SI units are numerically converted from the
correspondingrequirementsininch-poundunits.Forconductor
3. Ordering Information
sizesdesignatedbyAWGorkcmil,therequirementsinSIunits
3.1 Orders for material under this specification shall include
have been numerically converted from corresponding values
the following information:
stated or derived in inch-pound units. for conductor sizes
3.1.1 Quantity of each size and class,
designated by SI units only, the requirements are stated or
3.1.2 Conductor size: circular-mil area or American Wire
derived in SI units.
Gage (AWG) (Section 6),
1.3.1 For density, resitivity and temperature, the values
3.1.3 Class (see 1.2 and Table 1),
stated in SI units are to be regarded as standard.
3.1.4 Temper (see 10.2),
3.1.5 Whether coated or uncoated; if coated, designate type
NOTE 1—The significant differences in this specification from Specifi-
cation B8 are as follows: (1)The central core is permitted to contain up to
of coating (see 10.1 and 10.2),
seven wires drawn into the assembly with an infinite length of lay while
3.1.6 Details of special-purpose lays, if required (see 5.2),
1 2
This specification is under the jurisdiction of ASTM Committee B01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Conductors of Copper and Copper Alloys. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2006. Published November 2006. Originally the ASTM website.
approved in 1988. Last previous edition approved in 2001 as B784 – 01. DOI: Available from National Technical Information Service (NTIS), 5285 Port
10.1520/B0784-01R06. Royal Rd., Springfield, VA 22161, http://www.ntis.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
B784 – 01 (2006)
TABLE 1 Construction Requirements of Modified Concentric-Lay-Stranded Copper Conductors
NOTE 1—See Explanatory Note 5.
Class B Modified Class C Modified Class D Modified
Size
Circular Mils American Diameter Diameter Diameter
Number of Number of Number of
Wire Gage
Wires Wires Wires
(mils) (mm) (mils) (mm) (mils) (mm)
A
5 000 000 217 151.8 3.86 271 135.8 3.45 271 135.8 3.45
4 000 000 217 144.0 3.66 271 128.9 3.27 271 128.9 3.27
4 000 000 217 135.8 3.45 271 121.5 3.09 271 121.5 3.09
3 500 000 169 143.9 3.66 217 127.0 3.23 271 113.6 2.89
A
3 000 000 169 133.2 3.38 217 117.6 2.99 271 105.2 2.67
A
2 500 000 127 140.3 3.56 169 121.6 3.09 217 107.3 2.73
A
2 000 000 127 125.5 3.19 169 108.8 2.76 217 96.0 2.44
1 900 000 127 122.3 3.11 169 106.0 2.69 217 93.6 2.38
1 800 000 127 119.1 3.03 169 103.2 2.62 217 91.1 2.31
A
1 750 000 127 117.4 2.98 169 101.8 2.59 217 89.8 2.28
1 700 000 127 115.7 2.94 169 100.3 2.55 217 88.5 2.25
1 600 000 127 112.2 2.85 169 97.3 2.47 217 85.9 2.18
A
1 500 000 91 128.4 3.26 127 108.7 2.76 169 94.2 2.39
1 400 000 91 124.0 3.15 127 105.0 2.67 169 91.0 2.31
1 300 000 91 119.5 3.04 127 101.2 2.57 169 87.7 2.23
1 250 000 91 117.2 2.98 127 99.2 2.52 169 86.0 2.18
1 200 000 91 114.8 2.92 127 97.2 2.47 169 84.3 2.14
1 100 000 91 109.9 2.79 127 93.1 2.36 169 80.7 2.05
A
1 000 000 61 128.0 3.25 91 104.8 2.66 127 88.7 2.25
900 000 61 121.5 3.09 91 99.4 2.52 127 84.2 2.14
A
800 000 61 114.5 2.91 91 93.8 2.38 127 79.4 2.02
A
750 000 61 110.9 2.82 91 90.8 2.31 127 76.8 1.95
A
700 000 61 107.1 2.72 91 87.7 2.23 127 74.2 1.88
650 000 61 103.2 2.62 91 84.5 2.15 127 71.5 1.82
A
600 000 61 99.2 2.52 91 81.2 2.06 127 66.7 1.69
550 000 61 95.0 2.41 91 77.7 1.97 127 65.8 1.67
A
500 000 37 116.2 2.95 61 90.5 2.30 91 74.1 1.88
450 000 37 110.3 2.80 61 85.9 2.18 91 70.3 1.79
A
400 000 37 104.0 2.64 61 81.0 2.06 91 66.3 1.68
A
350 000 37 97.3 2.47 61 75.7 1.92 91 62.0 1.57
A
300 000 37 90.0 2.29 61 70.1 1.78 91 57.4 1.46
A
250 000 37 82.2 2.09 61 64.0 1.63 91 52.4 1.33
A
211 000 0000 19 105.5 2.68 37 75.6 1.92 61 58.9 1.50
A
167 000 000 19 94.0 2.39 37 67.3 1.71 61 52.4 1.33
A
133 000 00 19 83.7 2.13 37 60.0 1.52 61 46.7 1.19
A
105 000 0 19 74.5 1.89 37 53.4 1.36 61 41.6 1.06
A
83 000 1 19 66.4 1.69 37 47.6 1.21 61 37.0 0.94
A
These sizes of conductors provide for one or more schedules of preferred series and commonly are used in the industry. The sizes not marked are given simply as
a matter of reference and it is suggested that their use be discouraged.
3.1.7 Lagging, if required (see 14.2), requirement shall apply only to the two outer layers.The lay of
3.1.8 Special package marking, if required (Section 13), the layers other than the two outer layers shall be at the option
3.1.9 Place of inspection (Section 12), and of the manufacturer, unless otherwise agreed upon.
5.2 Other lays for special purposes shall be furnished by
4. Joints
special agreement between the manufacturer and the purchaser
4.1 Welds and brazes may be made in rods or in wires prior (Explanatory Note 3).
5.3 The direction of lay of the outer layer shall be left-hand
to final drawing.Welds and brazes may be made in the finished
individual wires composing the conductor, but shall not be unless the direction of lay is specified otherwise by the
purchaser.
closer together than prescribed in Table 2.
5.4 The direction of lay shall be reversed in successive
5. Lay
layers, unless otherwise specified by the purchaser.
5.1 The lay of a layer of wires shall be not less than eight
6. Construction
nor more than sixteen times the outside diameter of that layer,
6.1 The areas of cross section, numbers, and diameters of
except that for conductors composed of 37 wires or more, this
wires in the various classes of concentric-lay-stranded conduc-
tors shall conform to the requirements prescribed in Table 1.
TABLE 2 Minimum Distance Between Joints in the Completed
6.2 The diameters of the wires listed inTable 1 are nominal.
Conductor
Where“combinationstrand’’isrequiredinordertoinsulatethe
Number of Wires in Conductor Soft All Classes
conductor properly (strands in the outer layer having a larger
19 1 ft
A
diameter than those in the inner layers) the diameters shall be
20 and over 1 ft in a layer
A subject to a tolerance of 6 5 %, provided that the area of cross
Except as indicated, the limitations apply to closeness of joints throughout the
completed conductor. section after stranding is in accordance with Section 11.
B784 – 01 (2006)
TABLE 3 Standard Increments Due to Stranding
6.3 Where compressed stranding is required in order to
insulate the conductor properly, one or more layers of any Increment of Resistance
Type of Conductor
and Mass, %
stranded conductor consisting of 19 wires or more may be
Classes B Modified, C Modified, and D 2
slightly compressed, thereby reducing the outside diameter of
Modified, 2 000 000 cmil and under
the conductor by not more than 3 %, provided that the area of
Over 2 000 000 to 3 000 000 cmil 3
cross section after stranding is in accordance with Section 11.
Over 3 000 000 to 4 000 000 cmil 4
Over 4 000 000 to 5 000 000 cmil 5
7. Physical and Electrical Tests of Stranded Conductors
of Soft Wires
7.1 Tests for the electrical properties of wires composing
10. Requirements for Wires
conductors made from soft or annealed copper wire, bare or
10.1 The purchaser shall designate the type of wire and the
coated, shall be made before stranding.
kind of coating, if any, to be used in the conductor.
7.2 Tests for the physical properties of soft or annealed
10.2 Beforestranding,thecopperwireusedshallmeetallof
copper wire, bare or coated, may be made upon the wires
the requirements of ASTM Specifications B3, B33, and B189
before stranding or upon wires removed from the complete
that are applicable to its type.
strandedconductor,butneednotbemadeuponboth.Careshall
10.3 Thecentralcoreshallbemadeofwireofthesametype
be taken to avoid mechanical injury to wire removed from the
and temper as the concentric layers, unless otherwise specified.
conductor for the purpose of testing.
7.3 The physical properties of wires when tested before
11. Variation inArea
stranding shall conform to the applicable requirements of 10.2.
11.1 The area of cross section of the completed conductor
7.4 The physical properties of wires removed from the
shall be not less than 98 % of the area indicated in Column 1
completed stranded conductor shall be permitted to vary from
of Table 1. Unless otherwise specified by the purchaser, the
the applicable requirements of 10.2 by the following amounts
manufacturer may have the option of determining the cross-
(Explanatory Note 4):
sectional area by either of the following methods; except that
7.4.1 Average of Results Obtained onAll Wires Tested—The
in case of a question regarding area compliance, the method of
minimum elongation required shall be reduced in numerical
11.1.2 shall be used.
value 5 (for example, from 30 to 25 %) from the numerical
11.1.1 The area of cross section of a conductor may be
requirements for the wire before stranding.
determined by calculations from diameter measurements, ex-
7.4.2 Results Obtained on Individual Wires—The elonga-
pressed to four decimal places, of its component wires at any
tion of individual wires shall be reduced in numerical value 15
point when measured perpendicularly to their axes.
fromtheminimumrequirementsbeforestranding(thatis,10in
11.1.2 The area of cross section of a conductor may be
addition to the 5 allowed in 7.4.1), but in no case shall the
determined byTest Method B263. In applying that method, the
elongation of any individual wire be less than 5 %.
increment in mass resulting from stranding may be the appli-
7.5 In the event that the requirements prescribed in 7.4.2 are
cable value specified in 9.1 or may be calculated from the
met but those prescribed in 7.4.1 are not met, a retest shall be
measured component dimensions of the sample under test. In
permitted wherein all wires of the conductor shall be tested for
case of a question regarding area compliance, the actual mass
the purpose of final determination of conformance to 7.4.
increment due to stranding shall be calculated.
7.6 Elongation tests to determine compliance shall not be
made on the conductor as a unit (Explanatory Note 6).
12. Inspection
7.7 If a tinning, lead-coating, or lead-alloy-coating test is
12.1 Unless otherwise specified in the contract or purchase
required, it shall be made on the wires prior to stranding.
order, the manufacturer shall be responsible for the perfor-
mance of all inspection and test requirements specified.
8. Density
12.2 All inspections and tests shall be made at the place of
8.1 For the purpose of calculating mass per unit length,
manufactureunlessotherwiseagreeduponbythemanufacturer
cross sections, etc., the density of the copper shall be taken as
and the purchaser at the time of purchase.
3 3
0.32117 lb/in. or 8.89 g/cm at 20°C (Note 2 and Explanatory
12.3 The manufacturer shall afford the inspector represent-
Note 7).
ing the purchaser all reasonable manufacturer’s facilities to
satisfy that the material is being furnished in accordance with
NOTE 2—The term “mass” is being used in this specification as being
this specification.
more technically correct. It replaces the term “weight.”
9. Mass and Resistance
13. Product Marking
9.1 The mass and electrical resistance of a unit length of 13.1 The net mass, length (or lengths and number of
stranded conductor are a function of the length of lay. The lengths, if more than one length is included in the package),
approximate mass and electrical resistance may be determined size, kind of conductor, purchase order number, and any other
using the standard increments shown in Table 3. When greater marks required by the purchase order shall be marked on a tag
accuracy is desired, the increment based on the specific lay of attached to the end of the conductor inside of the package. The
the conductor may be calculated (Explanatory Note 8). same information, together with the manufacturer’s serial
B784 – 01 (2006)
number (if any) and all shipping marks required by the 15. Keywords
purchaser, shall appear on the outside of each package.
15.1 copperconductorsforinsulatedwires;coppermodified
concentric-lay-stranded; electrical copper conductor
...