1.1 本试验方法提供了一个程序，用于确定光伏组件承受落雹冲击力的能力。推进冰球用于模拟冰雹下落。 1.2 本试验方法定义了试样和安装试样的方法，规定了每个试样上的冲击位置，提供了确定任何尺寸冰球速度的方程式，提供了用冰球冲击试样的方法，提供了确定电气性能变化的方法，并规定了必须记录和报告的参数。 1.3 本试验方法不确定合格或不合格水平。冰球冲击阻力的可接受或不可接受水平的确定超出了本试验方法的范围。 1.4 未规定进行本试验所用冰球的尺寸。该测试方法可用于各种尺寸的冰球。 1.5 该测试方法可适用于集中器和非集中器模块。 1.6 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.7 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 有关具体预防说明，请参阅 5.1 部分 6. , 附注8 , 和 附注9 . 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 在许多地理区域，人们担心冰雹对光伏组件的影响。该试验方法可用于确定光伏组件承受冰雹冲击力的能力。在本试验方法中，光伏组件承受冰雹冲击的能力与其承受冰球冲击的测试能力有关。冲击的影响可能是模块的物理或电气退化。 4.2 本试验方法描述了安装试样、进行冲击试验和报告影响的标准程序。 4.2.1 提供了安装试样的程序，以确保在与其在光伏阵列中的使用相关的配置中测试模块。 4.2.2 选择了六个或六个以上的影响位置来代表模块上的脆弱位置，一般位置列于 表1 . 每个碰撞位置仅指定一次碰撞。 4.2.3 合成速度用于模拟伴随风的冰雹可能达到的速度。本试验方法中使用的合成速度由水平风速加垂直冰球终端速度的矢量相加确定。 4.2.4 本试验方法中使用冰球模拟冰雹。冰雹的形状、密度和脆弱性等特性是可变的（有关断裂特征，请参阅参考文献（10）） E822 ). 这些特性影响因素，例如作用在模块上的冲击力的持续时间和幅值以及冲击分布的面积。 冰球（密度、易碎性和终端速度接近冰雹范围）是目前已知的最接近冰雹的近似值。冰球通常比冰雹更硬、密度更大；因此，冰球模拟最坏情况下的冰雹。冰球和冰雹之间的主要区别可能是冰雹比冰球变化更大。冰球可以均匀重复制造，以确保弹丸具有已知特性。 4.2. 5. 冰球垂直于试样表面，这将最大动能传递给试样，不同于以掠射角度进行的非正常冲击。 4.3 使用本试验方法生成的数据可用于以下方面:( 1. )为了评估模块的抗冲击性( 2. )为了比较几个模块的抗冲击性( 3. )为选择在不同地理区域使用的模块提供通用基础，或( 4. )评估因其他环境因素（如风化）引起的模块抗冲击性变化。 4.3.1 该测试方法需要分析视觉效果以及电气测量。视觉效果通常比电测量更敏感；因此，电压和电流的绝对值不是关键值，但确定电气变化需要测试前后的可重复条件。 4.3.2 影响各种类型的光伏组件可能会产生一系列可观察的影响。对模块的物理影响可能会有所不同，从没有影响到冰球的穿透。 当模块没有明显的电气劣化时，可以看到模块中的一些物理变化。 4.3.3 电气变化可能从无影响到无输出不等。报告中必须描述影响的所有影响，以便对其重要性进行估计。 4.4 本试验方法未规定冰球的大小或速度或进行试验时使用的最大冲击次数。这些决定将基于预期冰雹发生的频率和严重程度以及测试的意图。 4.4.1 如果测试是为了评估单个模块或多个模块的抗冲击性，则可能需要使用几个尺寸和速度的冰球重复测试。通过这种方式，可以确定不同大小和速度的冰球的不同影响。但是，任何点都不得受到一次以上的影响（参见 7.10 ). 4.4.2 冰雹的大小和频率在不同的地理区域之间差异很大。如果正在进行测试以评估拟在特定地理区域使用的模块，则冰球大小应符合该区域所需的冰雹冲击阻力水平。 冰雹大小和频率的信息可在实践的附录X1中找到 E822 和本试验方法的脚注3和4，或可从当地历史天气记录中获得。 4.4.3 在冰雹风暴期间测试设计为存放位置的模块时，应相应地选择其他碰撞位置。 4.5 当材料暴露于各种环境因素时，模块的抗冰雹冲击性可能会发生变化。本试验方法可用于通过比较暴露于其他此类环境因素之前和之后测得的冰雹冲击阻力数据来评估退化。

1.1 This test method provides a procedure for determining the ability of photovoltaic modules to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. 1.2 This test method defines test specimens and 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, provides a method for determining changes in electrical performance, and specifies parameters that must be recorded and reported. 1.3 This test method 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 test method. 1.4 The size of the ice ball to be used in conducting this test is not specified. This test method can be used with various sizes of ice balls. 1.5 This test method may be applied to concentrator and nonconcentrator modules. 1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 This standard does not purport to address all of the safety problems, 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. For specific precautionary statements, refer to 5.1 , Section 6 , Note 8 , and Note 9 . 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. ====== Significance And Use ====== 4.1 In many geographic areas, there is concern about the effect of falling hail upon photovoltaic modules. This test method may be used to determine the ability of photovoltaic modules to withstand the impact forces of hailstones. In this test method, the ability of a photovoltaic module to withstand hail impact is related to its tested ability to withstand impact from ice balls. The effects of impact may be either physical or electrical degradation of the module. 4.2 This test method describes a standard procedure for mounting the test specimen, conducting the impact test, and reporting the effects. 4.2.1 The procedures for mounting the test specimen are provided to assure that modules are tested in a configuration that relates to their use in a photovoltaic array. 4.2.2 Six or more impact locations are chosen to represent vulnerable sites on modules and general locations are listed in Table 1 . Only a single impact is specified at each of the impact locations. 4.2.3 Resultant speed is used to simulate the speed that may be reached by hail accompanied by wind. The resultant speed used in this test method is determined by vector addition of horizontal wind velocity plus vertical ice ball terminal velocity. 4.2.4 Ice balls are used in this test method to simulate hailstones. Hailstones are variable in properties such as shape, density, and frangibility (for fracture characteristics, see Ref (10) in Practice E822 ). These properties affect factors such as the duration and magnitude of the impulsive force acting on the module and the area over which the impulse is distributed. Ice balls (with a density, frangibility, and terminal velocity near the range of hailstones) are the nearest hailstone approximation known at this time. Ice balls generally are harder and denser than hailstones; therefore, an ice ball simulates the worst case hailstone. Perhaps the major difference between ice balls and hailstones is that hailstones are more variable than ice balls. Ice balls can be uniformly and repeatedly manufactured to assure a projectile with known properties. 4.2.5 Ice balls are directed normal to the surface of a test specimen, which transfers the greatest kinetic energy to the test specimen, unlike a non-normal impact at a glancing angle. 4.3 Data generated using this test method may be used for the following: ( 1 ) to evaluate impact resistance of a module, ( 2 ) to compare the impact resistance of several modules, ( 3 ) to provide a common basis for selection of modules for use in various geographic areas, or ( 4 ) to evaluate changes in impact resistance of modules due to other environmental factors, such as weathering. 4.3.1 This test method requires analysis of visual effects, as well as electrical measurements. Visual effects are generally more sensitive than the electrical measurements; therefore, the absolute values for voltage and current are not critical, but repeatable conditions for before and after tests are required for determining electrical changes. 4.3.2 A range of observable effects may be produced by impacting various types of photovoltaic modules. Physical effects on modules may vary from no effect to penetration by the ice ball. Some physical changes in the module may be visible when there is no apparent electrical degradation of the module. 4.3.3 Electrical changes may vary from no effect to no output. All effects of the impacts must be described in the report so that an estimate of their significance can be made. 4.4 This test method does not specify the size or velocity of ice balls or maximum number of impacts to be used in making the test. These determinations will be based on frequency and severity of expected hail occurrences and the intent of the testing. 4.4.1 If the testing is being performed to evaluate impact resistance of a single module, or several modules, it may be desirable to repeat the test using several sizes and velocities of ice balls. In this manner, the different effects of various sizes and velocities of ice balls may be determined. However, no point shall be impacted more than once (see 7.10 ). 4.4.2 The size and frequency of hail varies significantly among various geographic areas. If testing is being performed to evaluate modules intended for use in a specific geographic area, the ice ball size should correspond to the level of hail impact resistance required for that area. Information on hail size and frequency can be found in Appendix X1 of Practice E822 and footnotes 3 and 4 of this test method, or may be available from local historical weather records. 4.4.3 When testing modules that are designed to be in a stowed position during hail storms, additional impact locations should be chosen accordingly. 4.5 The hail impact resistance of modules may change as the materials are exposed to various environmental factors. This test method may be used to evaluate degradation by comparison of hail impact resistance data measured before and after exposure to other such environmental factors.