ASTM A697/A697M-03(2008)
(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
This test method was developed for evaluating the ac magnetic properties of laminated cores made from flat-rolled magnetic materials.
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 A 34/A 34M and Terminology A 340. It depends upon these designated documents and a related reference test manual 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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
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Designation: A697/A697M − 03(Reapproved 2008)
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 standard. Within this standard, SI units are shown in brackets.
The values stated in each system may not be exact equivalents;
1.1 This test method covers the determination of several ac
therefore,eachsystemshallbeusedindependentlyoftheother.
magnetic properties of laminated cores made from flat-rolled
Combining values from the two systems may result in noncon-
magnetic materials.
formance with this standard.
1.2 This test method covers test equipment and procedures
1.9 This standard does not purport to address all of the
for the determination of impedance permeability and exciting
safety concerns, if any, associated with its use. It is the
power from voltage and current measurements, and core loss
responsibility of the user of this standard to establish appro-
from wattmeter measurements. These tests are made under
priate safety and health practices and determine the applica-
conditions of sinusoidal flux.
bility of regulatory limitations prior to use.
1.3 This test method covers tests for two general categories
2. Referenced Documents
(1 and 2) of cores based on size and application.
2.1 ASTM Standards:
1.4 Tests are provided for power and control size cores
A34/A34M Practice for Sampling and Procurement Testing
(Category 1) operating at inductions of 10 to 15 kG [1.0 to 1.5
of Magnetic Materials
T] and at frequencies of 50, 60, and 400 Hz.
A340 Terminology of Symbols and Definitions Relating to
1.5 Procedures and tests are provided for coupling and
Magnetic Testing
matchingtypetransformercores(Category2)overtherangeof
inductions from 100 G [0.01 T] or lower to 10 kG [1.0 T] and 3. Terminology
above at 50 to 60 Hz or above when covered by suitable
3.1 The terms and symbols listed below apply only to this
procurement specifications.
test method.The official list of symbols and definitions may be
1.6 This test method also covers tests for core loss and ac
found in Terminology A340.
impedance permeability under incremental test conditions (ac
3.2 Symbols:
magnetization superimposed on dc magnetization) for the
A = E lamination surface area, one side only,
s
above core types and at inductions up to those that cause the ac
A = EI lamination surface area, one side only,
ss
exciting current to become excessively distorted or reach
h = lamination stack height,
A = dc ammeter,
values that exceed the limits of the individual test equipment dc
I = dc current,
dc
components.
N = primary turns,
N = secondary turns,
1.7 This test method shall be used in conjunction with
N = tertiary turns,
Practice A34/A34M and Terminology A340. It depends upon
R = ammeter shunt resistance,
thesedesignateddocumentsandarelatedreferencetestmanual V = flux voltmeter,
f
w = lamination center leg width,
for detailed information which will not be repeated in this test
W = wattmeter, and
method.
Z = choke coil impedance.
1.8 The values and equations stated in customary (cgs-emu
4. Summary of Test Method
and inch-pound) or SI units are to be regarded separately as
4.1 For Category 1 cores, the recommended tests are made
at a frequency of 60 Hz and at a test induction within the range
from 10 through 15 kG [1.0 to 1.5 T].
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 Nov. 1, 2008. Published December 2008. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1974. Last previous edition approved in 2003 as A697/A697M – 03. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/A0697_A0697M-03R08. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A697/A697M − 03 (2008)
4.2 For Category 2 cores, the recommended tests are made 6.2.2 The coils listed in Table 2, for testing Category 2
at a frequency of 50 or 60 Hz and at inductions of 40, 100 or cores, have been designed to have characteristics that provide
200, 2000, 5000, 6000, 7000, and 10 000 G [0.004, 0.01 or a direct readout capability for incremental permeability. The
0.02, 0.2, 0.5, 0.6, 0.7, and 1.0 T]. Any or all may be required test coil is designed so that the primary winding 22.N
depending on the type of core material. 5100 2 π l , the secondary winding N =20 l , and the
=
1 2 1
tertiary winding N is designed so that the N 55=2 π l (and
3 3 1
5. Significance and Use
N /N = 20).
1 3
5.1 This test method was developed for evaluating the ac
6.2.3 The coils listed in Table 3 have been designed for
magnetic properties of laminated cores made from flat-rolled
testing Category 1 cores at a frequency of 400 Hz.
magnetic materials.
6.3 Flux Voltmeter—The flux voltmeter shall be a true
5.2 The reproducibility and repeatability of this test method
average responsive voltmeter calibrated to read =2 π/4 times
are such that this test method is suitable for design, specifica-
the full wave rectified average voltage so that its indications
tion acceptance, service evaluation, and research and develop-
will be identical to those of a true rms voltmeter on a pure
ment.
sinusoidal voltage. To produce the estimated precision of tests
under this test method, the full-scale errors shall not exceed
6. Apparatus
0.5 % (0.25 % or better preferred). Either digital or analog flux
6.1 The apparatus for testing under this test method shall
voltmeters are permitted. The normally high impedance of
consist of as many of the following components, described in
digital flux voltmeters is desirable to minimize loading effects.
6.2 through 6.12, as required to perform the desired test The internal resistance of an analog flux voltmeter shall not be
measurements.
less than 1000 Ω/V of full-scale indication.
6.2 Test Coils—In general, test coils are designed to sur- 6.4 A variable voltage divider on the input of the flux
round a square center leg stack (lamination stack height equal voltmeter may be used to scale the voltmeter reading. The
tocenterlegwidth).Theyconsistoftwoormorewindingswith voltage divider should provide for ratio adjustments to four
the secondary wound on the coil form first. Three groups of significant figures to establish the desired fraction of the
standard test coils are described in 6.2.1 through 6.2.3. Each of secondary voltage that is to be impressed on the flux voltmeter.
thesehasbeendesignedtoprovidespecificfeaturesduringtest. Care must be taken to assure that the voltage rating of a ratio
Because of turns, coil resistance, and magnitude of induced
transformer is adequate for use at the test frequency and
voltage, each has a particular field of application. voltage. A resistive voltage divider may be used with high
6.2.1 The coils listed in Table 1, for testing Category 1
impedance electronic voltmeters. Dividers having a total resis-
cores,havebeendesignedtohaveequalprimaryandsecondary tance of at least 10 KΩ for low-voltage tests and 100 KΩ or
turns and provide an induced voltage of 115 V when operating more for other tests are preferred. When a resistive voltage
at a peak flux density of 15 kG [1.5 T] at 60 Hz. divider is used, additional correction for instrument burden
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 − 03 (2008)
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 1.5w ⁄4 0.635 888 36 26.3 36 40 0.82 44 34 1.47
3 3
⁄8 0.9525 1.5w ⁄8 0.9525 1278 36 127.8 40 24 0.30 64 34 2.84
1 1
⁄2 1.270 1.5w ⁄2 1.270 1444 36 180.4 60 24 0.42 72 34 4.00
5 5
⁄8 1.588 1.5w ⁄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 1.5w ⁄4 1.905 2000 35 278.0 90 21 0.42 100 34 7.77
7 7
⁄8 2.222 1.5w ⁄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 1.5w 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 1
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-
G5 A /A
Turns Turns Turns ss s
to Size ance,Ω Size ance, Ω Size ance, Ω
in. cm in. cm
w
3 3
⁄8 0.9525 1.5w ⁄8 0.9525 458 33 19.06 458 33 24.2 64 34 2.84 1.308
1 1
⁄2 1.270 1.5w ⁄2 1.270 262 30 6.46 262 30 7.68 72 34 4.00 1.327
5 5
⁄8 1.588 1.5w ⁄8 1.588 162 27 2.37 162 27 2.74 83 34 5.52 1.329
3 3
⁄4 1.905 1.5w ⁄4 1.905 134 24 1.16 134 24 1.38 100 34 7.77 2.519
7 7
⁄8 2.222 1.5w ⁄8 2.222 82 20 0.34 82 20 0.40 116 34 10.3 3.407
1 2.540 1.5w 1 2.540 62 20 0.29 62 20 0.32 133 34 13.3 4.425
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
6.5 RMS Voltmeter, V—A true rms responsive voltmeter
distortion for proper use of one of these instruments as an rms ammeter.
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
permeability. This meter may be either an electronic or analog
voltmeter shall be the same as that specified for the flux
type. An analog instrument may be a moving iron-vane,
voltmeter. Either digital or analog voltmeters are permitted.
thermal, or electrodynamometer type. Sufficient current ranges
The normally high-input resistance of the digital rms voltme-
should be provided to cover the desired range of exciting
ters is desirable to minimize loading effects. The input resis-
currents.This meter shall have an accuracy of 1 % of full-scale
tance of an analog rms voltmeter shall not be less than 1000
indication or better. Its internal impedance should be less than
Ω/V of full-scale indication.
0.1 Ω for testing Category 1 cores. For Category 2 cores in
NOTE 1—Many electronic voltmeters are either peak responsive or
which the test coil resistance is already high, the ammeter’s
average responsive in their indications. Although these meters may have
input resistance may be higher (Note 2).Atrue rms responsive
scales that are marked RMS Volts, they should not be used for rms current
voltmeter (Note 1) of suitable accuracy
...
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