1.1 本试验方法涵盖所有住宅压力连接系统。中提供了应用于特定类型连接系统、固定螺钉中性母线连接器和扭合导线拼接连接器的详细示例 附录X1 和 附录X2 . 1.2 本试验方法的目的是评估住宅电气压力连接系统在循环温度变化（额定值内）和高湿度条件下的性能。 1.3 试验方法的局限性如下: 1.3.1 本试验方法不应被视为确认应用环境中的特定寿命。 1.3.2 本试验方法的适用性仅限于额定电压等于或低于600 V d-c或a-c RMS的压力连接系统。 1.3.3 除测量连接电阻所需的电流外，本试验方法仅限于温度和水蒸气暴露。 1.3.4 本试验方法不评估由于电气连接系统暴露于其他环境成分（例如（但不限于）以下示例）而可能在住宅应用中发生的退化: 1.3.4.1 家用化学品（液体或气体），如氨、漂白剂或其他清洁剂。 1.3.4.2 由于正常爱好或专业活动（如摄影、绘画、雕塑或类似活动）而产生的化学品。 1.3.4.3 施工或改建过程中遇到的环境，如直接暴露于雨水、未固化的湿混凝土、焊接或助焊剂和其他药剂。 1.3.5 本试验方法仅限于评估压力连接系统。 1.4 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熟悉所有危险，包括制造商提供的本产品/材料的适当安全数据表（SDS）中确定的危险，建立适当的安全、健康和环境实践，并在使用前确定监管限制的适用性。 1.5 本标准应用于测量和描述在受控实验室条件下响应电流的材料、产品或组件的特性，不应用于描述或评估在实际安装条件或实际火灾条件下材料、产品或组件的火灾危险或火灾风险。然而，该测试结果可作为火灾风险评估的要素，该评估考虑了与特定最终用途火灾危险评估相关的所有因素。 1.6 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====== 5.1 该测试的基本原理是电接触界面对温度和湿度循环的敏感性，该温度和湿度循环是电压力连接系统由于使用和安装环境而经历的。温度循环可能会导致配合电接触表面发生微动，从而使新鲜金属暴露在局部环境大气中。众所周知，潮湿暴露会促进新暴露金属表面的腐蚀。 因此，对于那些在热循环和湿度暴露条件下不能保持稳定的金属-金属接触表面的连接系统，这些暴露的重复序列导致接触表面的退化，表现为电位降增加。 5.2 相对于住宅使用中连接的预期寿命而言，测试持续时间较短。连接电阻的稳定性意味着抗因住宅服务中遇到的环境条件而恶化。由于测试暴露而增加的连接电阻表明电接触界面恶化。要保证恶化的连接类型的长期可靠性和安全性，需要对特定的指定环境和应用进行进一步评估。 5.3 使用- 建议以两种方式之一使用该试验方法。首先，它可以用于评估和报告特定连接系统的性能。对于此类用途，宜以摘要（或表格）格式报告结果，如第节所示 17 以及“当根据试验方法进行试验时，总结（或表格）中所示的结果是针对（插入连接说明）获得的”的声明 B812型 . 其次，它可以作为产品可接受性规范的基础。为此，必须由说明者确定最小试验时间和最大允许电位降增加。根据标准试验方法的使用，连接系统的规格应为:“当根据试验方法进行试验时，任何连接的最大电位降增加 B812型 在数周内，应为相对于参考连接的mV。”在本试验方法确定的限制范围内，最耐热循环/湿度劣化的连接系统在进行不确定时间试验时，相对于参考连接，电位降没有增加。通过本试验施加的对热循环/湿度条件抵抗力较低的连接将证明随着试验时间的增加，电位降逐渐增加。因此，以下规范示例按最严格（1号）到最不严格（3号）的顺序排列。 持续时间，周 最大电位降增加，mV 1. 52 0 2. 16 0.2 3. 4. 1

1.1 This test method covers all residential pressure connection systems. Detailed examples of application to specific types of connection systems, set-screw neutral bus connectors and twist-on wire-splicing connectors, are provided in Appendix X1 and Appendix X2 . 1.2 The purpose of this test method is to evaluate the performance of residential electrical pressure connection systems under conditions of cyclic temperature change (within rating) and high humidity. 1.3 The limitations of the test method are as follows: 1.3.1 This test method shall not be considered to confirm a specific lifetime in application environments. 1.3.2 The applicability of this test method is limited to pressure connection systems rated at or below 600 V d-c or a-c RMS. 1.3.3 This test method is limited to temperature and water vapor exposure in addition to electrical current as required to measure connection resistance. 1.3.4 This test method does not evaluate degradation which may occur in residential applications due to exposure of the electrical connection system to additional environmental constituents such as (but not limited to) the following examples: 1.3.4.1 Household chemicals (liquid or gaseous) such as ammonia, bleach, or other cleaning agents. 1.3.4.2 Chemicals as may occur due to normal hobby or professional activities such as photography, painting, sculpture, or similar activities. 1.3.4.3 Environments encountered during construction or remodeling such as direct exposure to rain, uncured wet concrete, welding or soldering fluxes and other agents. 1.3.5 This test method is limited to evaluation of pressure connection systems. 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use. 1.5 This standard should be used to measure and describe the properties of materials, products, or assemblies in response to electrical current flow under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual installation conditions or under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end 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. ====== Significance And Use ====== 5.1 The principal underlying the test is the sensitivity of the electrical contact interface to temperature and humidity cycling that electrical pressure connection systems experience as a result of usage and installation environment. The temperature cycling may cause micromotion at the mating electrical contact surfaces which can expose fresh metal to the local ambient atmosphere. The humidity exposure is known to facilitate corrosion on freshly exposed metal surfaces. Thus, for those connection systems that do not maintain stable metal-to-metal contact surfaces under the condition of thermal cycling and humidity exposure, repeated sequences of these exposures lead to degradation of the contacting surface indicated by potential drop increase. 5.2 The test is of short duration relative to the expected life of connections in residential usage. Stability of connection resistance implies resistance to deterioration due to environmental conditions encountered in residential service. Increasing connection resistance as a result of the test exposure indicates deterioration of electrical contact interfaces. Assurance of long term reliability and safety of connection types that deteriorate requires further evaluation for specific specified environments and applications. 5.3 Use— It is recommended that this test method be used in one of two ways. First, it may be used to evaluate and report the performance of a particular connection system. For such use, it is appropriate to report the results in a summary (or tabular) format such as shown in Section 17 , together with the statement “The results shown in the summary (or table) were obtained for (insert description of connection) when tested in accordance with Test Method B812 . Second, it may be used as the basis for specification of acceptability of product. For this use, the minimum test time and the maximum allowable increase in potential drop must be established by the specifier. Specification of connection systems in accordance with this use of the standard test method would be of the form: “The maximum potential drop increase for any connection, when tested in accordance with Test Method B812 for a period of weeks, shall be mV relative to the reference connections.” Connection systems that are most resistant to thermal-cycle/humidity deterioration, within the limitations of determination by this test method, show no increase in potential drop, relative to the reference connections, when tested for indefinite time. Connections that are less resistant to thermal-cycle/humidity conditions applied by this test will demonstrate progressive increases in potential drop with increasing time on test. Thus, the following examples of specifications are in the order of most stringent (No. 1) to least stringent (No. 3). Duration, weeks Maximum Potential Drop Increase, mV 1. 52 0 2. 16 0.2 3. 4 1.0