ASTM A697/A697M-13(2018)
(Test Method)Standard Test Method for Alternating Current Magnetic Properties of Laminated Core Specimen Using Voltmeter-Ammeter-Wattmeter Methods
Standard Test Method for Alternating Current Magnetic Properties of Laminated Core Specimen Using Voltmeter-Ammeter-Wattmeter Methods
SIGNIFICANCE AND USE
5.1 This test method was developed for evaluating the ac magnetic properties of laminated cores made from flat-rolled magnetic materials.
5.2 The reproducibility and repeatability of this test method are such that this test method is suitable for design, specification acceptance, service evaluation, and research and development.
SCOPE
1.1 This test method covers the determination of several ac magnetic properties of laminated cores made from flat-rolled magnetic materials.
1.2 This test method covers test equipment and procedures for the determination of impedance permeability and exciting power from voltage and current measurements, and core loss from wattmeter measurements. These tests are made under conditions of sinusoidal flux.
1.3 This test method covers tests for two general categories (1 and 2) of cores based on size and application.
1.4 Tests are provided for power and control size cores (Category 1) operating at inductions of 10 to 15 kG [1.0 to 1.5 T] and at frequencies of 50, 60, and 400 Hz.
1.5 Procedures and tests are provided for coupling and matching type transformer cores (Category 2) over the range of inductions from 100 G [0.01 T] or lower to 10 kG [1.0 T] and above at 50 to 60 Hz or above when covered by suitable procurement specifications.
1.6 This test method also covers tests for core loss and ac impedance permeability under incremental test conditions (ac magnetization superimposed on dc magnetization) for the above core types and at inductions up to those that cause the ac exciting current to become excessively distorted or reach values that exceed the limits of the individual test equipment components.
1.7 This test method shall be used in conjunction with Practice A34/A34M and Terminology A340. It depends upon these designated documents for detailed information which will not be repeated in this test method.
1.8 The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard. Within this standard, SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this standard.
1.9 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.
1.10 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
Relations
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: A697/A697M − 13 (Reapproved 2018)
Standard Test Method for
Alternating Current Magnetic Properties of Laminated Core
Specimen Using Voltmeter-Ammeter-Wattmeter Methods
This standard is issued under the fixed designationA697/A697M; 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 The values stated in each system may not be exact equivalents;
therefore,eachsystemshallbeusedindependentlyoftheother.
1.1 This test method covers the determination of several ac
Combining values from the two systems may result in noncon-
magnetic properties of laminated cores made from flat-rolled
formance with this standard.
magnetic materials.
1.9 This standard does not purport to address all of the
1.2 This test method covers test equipment and procedures
safety concerns, if any, associated with its use. It is the
for the determination of impedance permeability and exciting
responsibility of the user of this standard to establish appro-
power from voltage and current measurements, and core loss
priate safety, health, and environmental practices and deter-
from wattmeter measurements. These tests are made under
mine the applicability of regulatory limitations prior to use.
conditions of sinusoidal flux.
1.10 This international standard was developed in accor-
1.3 This test method covers tests for two general categories
dance with internationally recognized principles on standard-
(1 and 2) of cores based on size and application.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.4 Tests are provided for power and control size cores
mendations issued by the World Trade Organization Technical
(Category 1) operating at inductions of 10 to 15 kG [1.0 to 1.5
Barriers to Trade (TBT) Committee.
T] and at frequencies of 50, 60, and 400 Hz.
1.5 Procedures and tests are provided for coupling and
2. Referenced Documents
matchingtypetransformercores(Category2)overtherangeof
2.1 ASTM Standards:
inductions from 100 G [0.01 T] or lower to 10 kG [1.0 T] and
A34/A34M Practice for Sampling and Procurement Testing
above at 50 to 60 Hz or above when covered by suitable
of Magnetic Materials
procurement specifications.
A340 Terminology of Symbols and Definitions Relating to
1.6 This test method also covers tests for core loss and ac
Magnetic Testing
impedance permeability under incremental test conditions (ac
magnetization superimposed on dc magnetization) for the
3. Terminology
above core types and at inductions up to those that cause the ac
3.1 The terms and symbols listed below apply only to this
exciting current to become excessively distorted or reach
test method.The official list of symbols and definitions may be
values that exceed the limits of the individual test equipment
found in Terminology A340.
components.
3.2 Symbols:
1.7 This test method shall be used in conjunction with
A = E lamination surface area, one side only,
s
Practice A34/A34M and Terminology A340. It depends upon
A = EI lamination surface area, one side only,
ss
these designated documents for detailed information which
h = lamination stack height,
A = dc ammeter,
will not be repeated in this test method. dc
I = dc current,
dc
1.8 The values and equations stated in customary (cgs-emu
N = primary turns,
N = secondary turns,
and inch-pound) or SI units are to be regarded separately as
N = tertiary turns,
standard. Within this standard, SI units are shown in brackets.
R = ammeter shunt resistance,
V = flux voltmeter,
f
w = lamination center leg width,
This test method is under the jurisdiction of ASTM Committee A06 on
MagneticPropertiesandisthedirectresponsibilityofSubcommitteeA06.01onTest
Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2018. Published June 2018. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1974. Last previous edition approved in 2013 as A697/A697M – 13. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/A0697_A0697M-13R18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A697/A697M − 13 (2018)
standard test coils are described in 6.2.1 through 6.2.3. Each of
W = wattmeter, and
Z = choke coil impedance.
thesehasbeendesignedtoprovidespecificfeaturesduringtest.
Because of turns, coil resistance, and magnitude of induced
4. Summary of Test Method
voltage, each has a particular field of application.
4.1 For Category 1 cores, the recommended tests are made
6.2.1 The coils listed in Table 1, for testing Category 1
at a frequency of 60 Hz and at a test induction within the range
cores,havebeendesignedtohaveequalprimaryandsecondary
from 10 through 15 kG [1.0 to 1.5 T].
turns and provide an induced voltage of 115 V when operating
4.2 For Category 2 cores, the recommended tests are made at a peak flux density of 15 kG [1.5 T] at 60 Hz.
at a frequency of 50 or 60 Hz and at inductions of 40, 100 or
6.2.2 The coils listed in Table 2, for testing Category 2
200, 2000, 5000, 6000, 7000, and 10 000 G [0.004, 0.01 or
cores, have been designed to have characteristics that provide
0.02, 0.2, 0.5, 0.6, 0.7, and 1.0 T]. Any or all may be required
a direct readout capability for incremental permeability. The
depending on the type of core material.
test coil is designed so that the primary winding 22.N
5100=2 π l , the secondary winding N =20 l , and the
1 2 1
5. Significance and Use
tertiary winding N is designed so that the N 55=2 π l (and
3 3 1
5.1 This test method was developed for evaluating the ac
N /N = 20).
1 3
magnetic properties of laminated cores made from flat-rolled
6.2.3 The coils listed in Table 3 have been designed for
magnetic materials.
testing Category 1 cores at a frequency of 400 Hz.
5.2 The reproducibility and repeatability of this test method
6.3 Flux Voltmeter—The flux voltmeter shall be a true
are such that this test method is suitable for design, specifica-
tion acceptance, service evaluation, and research and develop- average responsive voltmeter calibrated to read =2 π/4 times
the full wave rectified average voltage so that its indications
ment.
will be identical to those of a true rms voltmeter on a pure
6. Apparatus
sinusoidal voltage. To produce the estimated precision of tests
under this test method, the full-scale errors shall not exceed
6.1 The apparatus for testing under this test method shall
0.5 % (0.25 % or better preferred). Either digital or analog flux
consist of as many of the following components, described in
voltmeters are permitted. The normally high impedance of
6.2 through 6.12, as required to perform the desired test
digital flux voltmeters is desirable to minimize loading effects.
measurements.
The internal resistance of an analog flux voltmeter shall not be
6.2 Test Coils—In general, test coils are designed to sur-
less than 1000 Ω/V of full-scale indication.
round a square center leg stack (lamination stack height equal
tocenterlegwidth).Theyconsistoftwoormorewindingswith 6.4 A variable voltage divider on the input of the flux
the secondary wound on the coil form first. Three groups of voltmeter may be used to scale the voltmeter reading. The
TABLE 1 Test Coils for EI Used at 60 Hz in Power Applications, Category 1
NOTE 1—Winding forms should allow for at least 0.030-in. [0.076-cm] clearance between lamination stack and coil form, and its walls should not be
thicker than necessary to provide adequate insulation and strength for coil support.
NOTE 2—These coils are also suitable for use at 50 Hz and other frequencies.
NOTE 3—N winding is required for setting induction when incremental properties are to be measured or where other instruments interfere with
induction measurements. It is composed of one layer of No. 34 wire so that N 55 2π l where l is the magnetic path length.
3 œ 1 1
Lamination Test Winding (see 6.2.1)
Center Leg N N N
1 2 3
Length
Width (w) Stack Height (h)
Wire Resist- Wire Resist- Wire Resist-
Relative Turns Turns Turns
Size ance, Ω Size ance, Ω Size ance, Ω
in. cm in. cm
to w
3 3
⁄8 0.9525 1.5w ⁄4 1.905 1000 35 84.3 1000 35 103.8 64 34 2.84
⁄2 1.270 1.5w 1 2.540 800 34 68.3 800 34 80.7 72 34 4.00
5 7
⁄8 1.588 1.5w ⁄8 2.222 800 33 56.6 800 33 67.8 83 34 5.54
3 3
⁄4 1.905 1.5w ⁄4 1.905 800 31 36.6 800 31 43.5 100 34 7.77
7 7
⁄8 2.222 1.5w ⁄8 2.222 588 28 15.4 588 28 18.1 116 34 9.86
15 15
⁄16 2.381 1.5 w ⁄16 2.381 513 26 8.75 513 26 10.6 136 34 12.8
1 2.540 1.5w 1 2.540 450 25 6.02 450 25 7.44 133 34 13.3
1 1
1 ⁄8 2.857 1.5 w 1 ⁄8 2.857 356 24 4.45 356 24 5.37 150 34 16.7
1 1
1 ⁄4 3.175 1.5 w 1 ⁄4 3.175 288 22 2.43 288 22 2.92 167 34 20.4
3 3
1 ⁄8 3.493 1.5 w 1 ⁄8 3.493 238 20 1.43 238 20 1.75 183 34 24.3
1 1
1 ⁄2 3.810 1.5 w 1 ⁄2 3.810 200 18 0.82 200 18 0.98 200 34 28.8
5 5
1 ⁄8 4.127 1.5 w 1 ⁄8 4.127 170 14 0.35 170 14 0.46 245 34 38.0
3 3
1 ⁄4 4.445 1.5 w 1 ⁄4 4.445 147 16 0.45 147 16 0.52 233 34 38.7
1 1
2 ⁄8 5.397 1.5 w 2 ⁄8 5.397 100 12 0.16 100 12 0.20 283 34 56.6
1 1
2 ⁄4 5.715 1.5 w 2 ⁄4 5.715 89 10 0.11 89 10 0.13 320 34 67.5
1 1
2 ⁄2 6.350 1.5 w 2 ⁄2 6.350 72 10 0.10 72 10 0.11 333 34 73.9
3 7.62 1.5w 1 ⁄2 3.810 76 10 0.11 76 10 0.11 400 34 111.0
4 10.16 1.5w 2 5.080 57 10 0.09 57 10 0.10 534 34 148.0
A697/A697M − 13 (2018)
TABLE 2 Test Coils for EI Laminations Used in General Magnetic Applications, Category 2
NOTE 1—Winding forms should allow for at least 0.030-in. [0.076-cm] clearance between lamination stock and coil form, and its walls should be not
thicker than necessary to provide adequate insulation and strength for coil support.
NOTE 2—These coils may be used at any frequency where voltage does not become excessively large.
NOTE 3—N winding is required for setting production when incremental properties are to be measured or other instruments interfere with induction
measurements. It is composed of one layer of No. 34 wire so that N 55 2π l where l is the magnetic path length.
3 œ 1 1
Lamination Test Windings (see 6.2.2)
Center Leg N N N
1 2 3
Length
Width (w) Stack Height (h)
Wire Resist- Wire Resist- Wire Resist-
Relative Turns Turns Turns
Size ance, Ω Size ance, Ω Size ance, Ω
in. cm in. cm
to w
3 3
⁄16 0.4763 1.5 w ⁄16 0.4763 722 36 24.2 32 30 0.37 36 34 0.997
1 1
⁄4 0.635 1.5 w ⁄4 0.635 888 36 26.3 36 40 0.82 44 34 1.47
3 3
⁄8 0.9525 1.5 w ⁄8 0.9525 1278 36 127.8 40 24 0.30 64 34 2.84
1 1
⁄2 1.270 1.5 w ⁄2 1.270 1444 36 180.4 60 24 0.42 72 34 4.00
5 5
⁄8 1.588 1.5 w ⁄8 1.588 1666 36 263.2 75 24 0.58 83 34 5.53
11 11
⁄16 1.746 1.5 w ⁄16 1.746 1822 36 294.4 82 23 0.55 92 34 6.64
3 3
⁄4 1.905 1.5 w ⁄4 1.905 2000 35 278.0 90 21 0.42 100 34 7.77
7 7
⁄8 2.222 1.5 w ⁄8 2.222 2333 34 295.7 105 21 0.45 116 34 10.3
15 15
⁄16 2.381 1.5 w ⁄16 2.381 2711 34 374.6 122 20 0.55 136 34 12.8
1 2.540 1.5 w 1 2.540 2666 34 373.9 120 20 0.55 133 34 13.3
TABLE 3 Test Coils for EI Laminations Used at 400 Hz in Power and Other Applications, Category 1
NOTE 1—Winding forms should allow for at least 0.030-in. [0.076-cm] clearance between lamination stack and coil form, and its walls should be not
thicker than necessary to provide adequate insulation and strength for coil support.
NOTE 2— These coils are also suitable for use at other frequencies.
NOTE 3—This winding is required for setting induction when incremental properties are to be measured or where other instruments interfere with
induction measurements. It is composed of one layer of No. 34 wire so that N 55 2π l where l is the magnetic path length.
3 œ 1
Lamination Test Windings (see 6.2.3)
Ratio
Center Leg N N N
1 2 3
Length
Width (w) Stack Height (h)
Relative Wire Resist- Wire Resist- Wire Resist-
G 5 A /A
ss s
Turns Turns Turns
to Size ance, Ω Size ance, Ω Size ance, Ω
in. cm in. cm
w
3 3
⁄8 0.95251.5 w ⁄8 0.9525 458 33 19.06 458 33 24.2 64 34 2.84 1.308
1 1
⁄2 1.270 1.5 w ⁄2 1.270 262 30 6.46 262 30 7.68 72 34 4.00 1.327
5 5
⁄8 1.588 1.5 w ⁄8 1.588 162 27 2.37 162 27 2.74 83 34 5.52 1.329
3 3
⁄4 1.905 1.5 w ⁄4 1.905 134 24 1.16 134 24 1.38 100 34 7.77 2.519
7 7
⁄8 2.222 1.5 w ⁄8 2.222 82 20 0.34 82 20 0.40 116 34 10.3 3.407
1 2.540 1.5 w 1 2.540 62 20 0.29 62 20 0.32 133 34 13.3 4.425
voltage divider should provide for ratio adjustments to four The normally high-input resistance of the digital rms voltme-
significant figures to establish the desired fraction of the ters is desirable to minimize loading effects. The input resis-
secondary voltage that is to be impressed on the flux voltmeter. tance of an analog rms voltmeter shall not be less than 1000
Care must be taken to assure that the voltage rating of a ratio Ω/V of full-scale indication.
transformer is adequate for use at the test frequency and
NOTE 1—Many electronic voltmeters are either peak responsive or
voltage. A resistive voltage divider may be used with high
average responsive in their indications. Although these meters may have
impedance electronic voltmeters. Dividers having a total resis-
scales that are marked RMS Volts, they should not be used for rms current
tance of at least 10 KΩ for low-voltage tests and 100 KΩ or or rms voltage measurements when distorted waves are present.They may
indicate the rms values of voltages with little distortion but should not be
more for other tests are preferred. When a resistive voltage
relied upon for rms voltage measurements in magnetic test circuits. When
divider is used, additional correction for instrument burden
flux is held closely sinusoidal, these probable errors can sometimes be
may be required to eliminate the effect of the resistive losses in
ignored for rms voltage measurements at the lower inductions. However,
the voltage divider upon measurements.
the current waveform under these conditions always has too much
distortion for proper use of one of these instruments as an rms ammeter.
6.5 RMS Voltmeter, V—A true rms responsive voltmeter
shall be used to indicate the rms voltage for exciting power 6.6 RMS Ammeter—A true rms responsive meter shall be
measurements. It may also be used for evaluating the form used to measure the rms exciting current for calculating
factorofthevoltageinducedinthesecondaryofthetestfixture exciting power or magnetizing force, H , for impedance
z
and for evaluating instrument losses. The accuracy of the rms perm
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