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ASTM E2047-99

(Test Method)

Standard Test Method for Wet Insulation Integrity Testing of Photovoltaic Arrays

Standard Test Method for Wet Insulation Integrity Testing of Photovoltaic Arrays

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1.1 This test method covers a procedure to determine the insulation resistance of a photovoltaic (PV) array (or its component strings), that is, the electrical resistance between the array's internal electrical components and is exposed, electrically conductive, non-current carrying parts and surfaces of the array.
1.2 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of this test method.
1.3 There is no similar or equivalent ISO standard.
1.4 Units-The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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 non-conformance with the standard.
1.5 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 to determine the applicability of regulatory limitations prior to use.

General Information

Status
Historical
Publication Date
09-Oct-1999
ICS
27.160 - Solar energy engineering
Technical Committee
E44 - Solar, Geothermal and Other Alternative Energy Sources
Drafting Committee
E44.09 - Photovoltaic Electric Power Conversion
Current Stage
Ref Project

Relations

Replaced By
ASTM E2047-05 - Standard Test Method for Wet Insulation Integrity Testing of Photovoltaic Arrays
Effective Date
01-Apr-2005
Referred By
ASTM E3010-15(2019)e1 - Standard Practice for Installation, Commissioning, Operation, and Maintenance Process (ICOMP) of Photovoltaic Arrays
Effective Date
10-Oct-1999

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ASTM E2047-99 - Standard Test Method for Wet Insulation Integrity Testing of Photovoltaic ArraysASTM E2047-99 - Standard Test Method for Wet Insulation Integrity Testing of Photovoltaic Arrays
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ASTM E2047-99 - Standard Test Method for Wet Insulation Integrity Testing of Photovoltaic Arrays
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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:E2047–99
Test Method for
Wet Insulation Integrity Testing of Photovoltaic Arrays
This standard is issued under the fixed designation E 2047; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope voltaic circuit and exposed, electrically conductive non-
current-carrying parts and surfaces of the array.
1.1 This test method covers a procedure to determine the
3.2.2 metal oxide varistor MOV, n—a surge protection
insulation resistance of a photovoltaic (PV) array (or its
device.
component strings), that is, the electrical resistance between
3.2.3 photovoltaic circuit—the active electrical circuit that
the array’s internal electrical components and is exposed,
conducts the photovoltaic generated power.
electrically conductive, non-current carrying parts and surfaces
of the array.
4. Summary of Test Method
1.2 This test method does not establish pass or fail levels.
4.1 A procedure is provided for testing the electrical isola-
The determination of acceptable or unacceptable results is
tion between the array’s internal electrical components and its
beyond the scope of this test method.
exposed, electrically conductive, non-current carrying parts
1.3 There is no similar or equivalent ISO standard.
and surfaces of the array.
1.4 Units—The values stated in either SI units or inch-
4.2 The procedure offers two ways to connect the array
pound units are to be regarded separately as standard. The
during the test, either open-circuited or short-circuited. Each
values stated in each system may not be exact equivalents;
option has advantages and disadvantages (see 5.5).
therefore, each system shall be used independently of the other.
4.3 Awetting solution is applied to the array, then a voltage
Combining values from the two systems may result in non-
is applied between the PV circuit and the exposed, electrically
conformance with the standard.
conductive, non-current carrying parts and surfaces of the
1.5 This standard does not purport to address all of the
array, while monitoring the current or resistance, to find
safety concerns, if any, associated with its use. It is the
localized regions where the insulation resistance is signifi-
responsibility of the user of this standard to establish appro-
cantly reduced by the wetting solution. The array is then
priate safety and health practices and determine the applica-
inspected for evidence of possible arcing.
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents
5.1 The design of a PV module or system intended to
2.1 ASTM Standards:
2 provide safe conversion of the sun’s radiant energy into useful
E 772 Terminology Relating to Solar Energy Conversion
electricitymusttakeintoconsiderationthepossibilityofhazard
E 1328 Terminology Relating to Photovoltaic Solar Energy
2 should the user come into contact with the electrical potential
Conversion
of the array. In addition, the insulation system provides a
E 1462 Standard Test Methods for Insulation Integrity and
2 barrier to electrochemical corrosion, and insulation flaws can
Ground Path Continuity of Photovoltaic Modules
result in increased corrosion and reliability problems. This test
3. Terminology method describes a procedure for verifying that the design and
construction of the array provides adequate electrical isolation
3.1 Definitions—Definitions of terms used in this test
through normal installation and use.At no location on the array
method may be found in Terminologies E 772 and E 1328.
should the PV-generated electrical potential be accessible, with
3.2 Definitions of Terms Specific to This Standard:
the obvious exception of the output leads. The isolation is
3.2.1 insulation resistance, n—the electrical resistance of a
necessary to provide for safe and reliable installation, use, and
photovoltaic array’s insulation, measured between the photo-
service of the PV system.
5.2 This test method describes a procedure for determining
the ability of the array to provide protection from electrical
This test method is under the jurisdiction of ASTM Committee E-44 on Solar,
hazards. Its primary use is to find insulation flaws that could be
GeothermalandOtherAlternativeEnergySources,andisthedirectresponsibilityof
dangerous to persons who may come into contact with the
Subcommittee E44.09 on Photovoltaic Electrical Power Conversion.
array. Corrective action taken to address such flaws is beyond
Current edition approved October 10, 1999. Published December 1999.
Annual Book of ASTM Standards, Vol 12.02. the scope of this test method.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E2047
5.3 This procedure may be specified as part of a series of must be sufficient to reach all of the test segment surfaces and
acceptance tests involving performance measurements and maintain wetted surfaces, front and back.
demonstration of functional requirements. Large arrays can be
NOTE 1—The spray pressure is only enough to completely wet the
tested in smaller segments. The size of the array segment to be
exposed surfaces; it is not intended to penetrate enclosed spaces such as
tested (called “circuit under test” in this test method) is usually
the interiors of junction boxes. It is not necessary to use a forceful stream
selected at a convenient break point and sized such that the because the wetting agent helps to penetrate small crevices.
expected resistance or current reading is within the middle
6.4 Array Shorter—A dc-rated switch, circuit beaker or
third of the meter’s range.
other device capable of interrupting the maximum short circuit
5.4 Insulation leakage resistance and insulation leakage
current of the circuit under test. The array shorter is only
current leakage are strong functions of array dimensions,
required if the short-circuited option is used.
ambient relative humidity, absorbed water vapor, and other
6.4.1 The array shorter must be rated for the maximum
factors.Forthisreason,itistheresponsibilityoftheuserofthis
open-circuit voltage of the circuit under test plus the insulation
test method to specify the minimum acceptable leakage resis-
tester or ohmmeter.
tance for this test.
6.4.2 The wiring between the array shorter and the positive
5.4.1 Even though a numerical quantity is specified, actual
and negative terminals of the circuit under test must also be
results are often pass-fail in that when a flaw is found, the
rated for the continuous maximum short-circuit current of the
leakage current changes from almost nothing to the full scale
circuit under test.
value on the meter.
5.5 The user of this test method must specify the option
7. Hazards
used for connection to the array during the test. The short-
7.1 Touchingthemodulesorarrayduringthetestingmaybe
circuited option requires a shorting device with leads to
hazardous because of the high voltage applied.
connect the positive and negative legs of the circuit under test.
7.2 Use caution whenever short circuiting any high voltage
For larger systems, where the shorting device may have to be
PV array. It may be advisable to reduce the risk involved by
rated for high current and voltage levels, the open-circuited
short-circuiting the array at night, when the current and voltage
option may be preferred. The open-circuited option requires
are minimized.
the user to correct readings to account for the PV-generated
7.3 The megohmmeter or insulation tester should be turned
voltage, and the procedure for making such corrections is
off while wetting the array. This may not always be desirable,
beyond the scope of this test method. The short-circuited
such as when trying to pinpoint the location of an insulation
option may be easier for small systems where the voltage and
flaw.Inthesecases,appropriatepersonnelprotection(electrical
current levels are low and the distance between the plus and
gloves with keepers, safety glasses, etc.) should be worn and
minus leads of the circuit under test are small. The short-
care should be taken to keep the wetting solution from entering
circuited option minimizes the chance of exposing array
the gloves, boots, etc.
components to voltage levels above those for which they are
rated.
8. Procedure
6. Apparatus
8.1 Assemble the requisite equipment and personnel at the
6.1 Choose one of the following, depending on the option array to be tested.
selected (see 4.2 and 5.5): 8.2 Prepare the wetting solution.
6.1.1 Variable dc Voltage Power Supply—A dc voltage 8.3 Measure and record the site meteorological conditions
power supply capable of providing a nominal test voltage of (irradiance, ambient temperature, wind speed) or arrange for
500V, as specified inTest Method E 1462.Acommon term for the data to be measured by the site data acquisition system.
this apparatus is insulation tester.
NOTE 2—It is recommended that this test not be performed under
6.1.2 Megohmmeter—A high-impedance ohmmeter, or
conditions where the ambient temperature is greater than 100°F (40°C) or
similar device, capable of adequately measuring leakage resis-
thewindspeedisgreaterthan17mph(7.5m/s),sincehighvaluesofeither
tance in the range of anticipated readings, and that can provide make it difficult to keep the array wet long enough to make the necessary
measurements. If the short-circuited option is used, it may be necessary to
a nominal test voltage of 500 V.
conduct the test at a reduced i
...

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4.1 The design of a photovoltaic module or system intended to provide safe conversion of the sun's radiant energy into useful electricity must take into consideration the possibility of hazard should the user come into contact with the electrical potential of the module or system. In addition, the insulation system provides a barrier to electrochemical corrosion, and insulation flaws can result in increased corrosion and reliability problems. These test methods describe procedures for verifying that the design and construction of the module provides adequate electrical isolation through normal installation and use. At no location on the module should the PV-generated electrical potential be accessible, with the obvious exception of the output leads. This isolation is necessary to provide for safe and reliable installation, use, and service of the photovoltaic system.  
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FIG. 1 Hot Spot Effect  
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5.1 This practice can be used to determine an expected capacity for an existing or a proposed photovoltaic system in a particular location during a specified period of time (see data collection period in Test Method E2848).  
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2.2 This practice describes a standard procedure for mounting the test specimen, conducting the impact test, and reporting the effects.  
2.2.1 The procedures for mounting cover plate materials and collectors are provided to ensure that they are tested in a configuration that relates to their use in a solar collector.  
2.2.2 The corner locations of the four impacts are chosen to represent vulnerable sites on the cover plate. Impacts near corner supports are more critical than impacts elsewhere. Only a single impact is specified at each of the impact locations. For test control purposes, multiple impacts in a single location are not permitted because a subcritical impact may still cause damage that would alter the response to subsequent impacts.  
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2.2.4 Ice balls are used in this practice to simulate hailstones because natural hailstones are not readily available to use, and ice balls closely approximate hailstones. However, no direct relationship has been established between the effect of impact of ice balls and hailstones. Hailstones are highly variable in properties such as shape, density, and frangibility.2 These properties affect factors such as the kinetic energy delivered to the cover plate, the period during ...
SCOPE
1.1 This practice covers a procedure for determining the ability of cover plates for flat-plate solar collectors to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. This practice is not intended to apply to photovoltaic cells or arrays.  
1.2 This practice defines two types of test specimens, describes methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, and specifies parameters that must be recorded and reported.  
1.3 This practice does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice-ball impact resistance is beyond the scope of this practice.  
1.4 The size of ice ball to be used in conducting this test is not specified in this practice. This practice can be used with various sizes of ice balls.  
1.5 The categories of solar collector cover plate materials to which this practice may be applied cover the range of:  
1.5.1 Brittle sheet, such as glass,  
1.5.2 Semirigid sheet, such as plastic, and  
1.5.3 Flexible membrane, such as plastic film.  
1.6 Solar collector cover materials should be tested as:  
1.6.1 Part of an assembled collector (Type 1 specimen), or  
1.6.2 Mounted on a separate test frame cover plate holder (Type 2 specimen).  
1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.8 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.  
1.9 This international standard was developed in accordance with internatio...

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ASTM
ASTM E781-86(2023)(Practice)
Standard Practice for Evaluating Absorptive Solar Receiver Materials When Exposed to Conditions Simulating Stagnation in Solar Collectors with Cover Plates

SIGNIFICANCE AND USE
4.1 Although this practice is intended for evaluating solar absorber materials and coatings used in flat-plate collectors, no single procedure can duplicate the wide range of temperatures and environmental conditions to which these materials may be exposed during in-service conditions.  
4.2 This practice is intended as a screening test for absorber materials and coatings. All conditions are chosen to be representative of those encountered in solar collectors with single cover plates and with no added means of limiting the temperature during stagnation conditions.  
4.3 This practice uses exposure in a simulated collector with a single cover plate. Although collectors with additional cover plates will produce higher temperatures at stagnation, this procedure is considered to provide adequate thermal testing for most applications.
Note 1: Mathematical modeling has shown that a selective absorber, single glazed flat-plate solar collector can attain absorber plate stagnation temperatures as high as 226 °C (437 °F) with an ambient temperature of 37.8 °C (100 °F) and zero wind velocity, and a double glazed one as high as 245 °C (482 °F) under these conditions. The same configuration solar collector with a nonselective absorber can attain absorber stagnation temperatures as high as 146 °C (284 °F) if single glazed, and 185 °C (360 °F) if double glazed, with the same environmental conditions (see “Performance Criteria for Solar Heating and Cooling Systems in Commercial Buildings,” NBS Technical Note 1187).4  
4.4 This practice evaluates the thermal stability of absorber materials. It does not evaluate the moisture stability of absorber materials used in actual solar collectors exposed outdoors. Moisture intrusion into solar collectors is a frequent occurrence in addition to condensation caused by diurnal breathing.  
4.5 This practice differentiates between the testing of spectrally selective absorbers and nonselective absorbers.  
4.5.1 Testing Spectrally Selective...
SCOPE
1.1 This practice covers a test procedure for evaluating absorptive solar receiver materials and coatings when exposed to sunlight under cover plate(s) for long durations. This practice is intended to evaluate the exposure resistance of absorber materials and coatings used in flat-plate collectors where maximum non-operational stagnation temperatures will be approximately 200 °C (392 °F).  
1.2 This practice shall not apply to receiver materials used in solar collectors without covers (unglazed) or in evacuated collectors, that is, those that use a vacuum to suppress convective and conductive thermal losses.  
1.3 The values stated in SI units are to be regarded as the standard.  
1.4 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.  
1.5 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.

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ASTM E744-07(2022)(Practice)
Standard Practice for Evaluating Solar Absorptive Materials for Thermal Applications

SIGNIFICANCE AND USE
4.1 The methods in this practice are intended to aid in the assessment of long-term performance by comparative testing of absorptive materials. The results of the methods, however, have not been shown to correlate to actual in-service performance.  
4.2 The testing methodology in this practice provides two testing methods, in accordance with Fig. 1.
FIG. 1 Outline of Test Method Options  
4.2.1 Method A, which aims at decreasing the time required for evaluation, uses a series of individual tests to simulate various exposure conditions.  
4.2.2 Method B utilizes a single test of actual outdoor exposure under conditions simulating thermal stagnation.  
4.2.3 Equivalency of the two methods has not yet been established.
SCOPE
1.1 This practice covers a testing methodology for evaluating absorptive materials used in flat plate or concentrating collectors, with concentrating ratios not to exceed five, for solar thermal applications. This practice is not intended to be used for the evaluation of absorptive surfaces that are (1) used in direct contact with, or suspended in, a heat-transfer liquid, (that is, trickle collectors, direct absorption fluids, etc.); (2) used in evacuated collectors; or (3) used in collectors without cover plate(s).  
1.2 Test methods included in this practice are property measurement tests and aging tests. Property measurement tests provide for the determination of various properties of absorptive materials, for example, absorptance, emittance, and appearance. Aging tests provide for exposure of absorptive materials to environments that may induce changes in the properties of test specimens. Measuring properties before and after an aging test provides a means of determining the effect of the exposure.  
1.3 The assumption is made that solar radiation, elevated temperature, temperature cycles, and moisture are the primary factors that cause degradation of absorptive materials. Aging tests are described for exposure of specimens to these factors.  
Note 1: For some geographic locations, other factors, such as salt spray and dust erosion, may be important. They are not evaluated by this practice.  
1.4 The values stated in SI units are to be regarded as the standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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ASTM E881-92(2022)(Practice)
Standard Practice for Exposure of Solar Collector Cover Materials to Natural Weathering Under Conditions Simulating Stagnation Mode

SIGNIFICANCE AND USE
4.1 This practice describes a weathering box test fixture and establishes limits for the heat loss coefficients. Uniform exposure guidelines are provided to minimize the variables encountered during outdoor exposure testing.  
4.2 Since the combination of elevated temperature and solar radiation may cause some solar collector cover materials to degrade more rapidly than either exposure alone, a weathering box that elevates the temperature of the cover materials is used.  
4.3 This practice may be used to assist in the evaluation of solar collector cover materials in the stagnation mode. No single temperature or procedure can duplicate the range of temperatures and environmental conditions to which cover materials may be exposed during stagnation conditions. To assist in evaluation of solar collector cover materials in the operational mode, Practice E782 should be used. Insufficient data exist to obtain exact correlation between the behavior of materials exposed in accordance with this practice and actual in-service performance.  
4.4 This practice may also be useful in comparing the performance of different materials at one site or the performance of the same material at different sites, or both.  
4.5 Means of evaluating the effects of weathering are provided in Practice E765, and in other ASTM test methods that evaluate material properties.  
4.6 Exposures of the type described in this practice may be used to evaluate the stability of solar collector cover materials when exposed outdoors to the varied influences that comprise weather. Exposure conditions are complex and changeable. Important factors are material temperature, climate, time of year, presence of industrial pollution, etc. Generally, because it is difficult to define or measure precisely the factors influencing degradation due to weathering, results of outdoor exposure tests must be taken as indicative only. Repeated exposure testing at different seasons over a period of more than one year is req...
SCOPE
1.1 This practice covers a procedure for the exposure of solar collector cover materials to the natural weather environment at elevated temperatures that approximate stagnation conditions in solar collectors having a combined back and edge loss coefficient of less than 1.5 W/(m2·°C).  
1.2 This practice is suitable for exposure of both glass and plastic solar collector cover materials. Provisions are made for exposure of single and double cover assemblies to accommodate the need for exposure of both inner and outer solar collector cover materials.  
1.3 This practice does not apply to cover materials for evacuated collectors, photovoltaic cells, flat-plate collectors having a combined back and edge loss coefficient greater than 1.5 W/(m2·°C), or flat-plate collectors whose design incorporates means for limiting temperatures during stagnation.  
1.4 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.  
1.5 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.

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