NFPA 70E and IEEE 1584 are defining standards for arc flash hazard analysis. Both assume three-phase faults for calculations since three-phase power distribution is predominant in utility and industrial applications; however, arc flash in single-phase systems is excluded. Single-phase faults to neutral or ground or single phase-to-phase faults can occur in a variety of circumstances. Such events may have the potential to produce arc flash and blast that would pose a significant safety concern. This paper describes a recent doctoral research investigation of arc flash in one single-phase configuration. Experiments were sponsored by UL and performed at the Schneider Electric High-Power Laboratory in Cedar Rapids, Iowa. This facility provided a test article; a full suite of voltage, current, and temperature instrumentation; and high-speed video recording. Experimental work revealed incident energy values less than 0.2 cal/cm2 for 240-volt single-phase arc fault events though there was still significant flash and splatter of molten wire residue. 480 V single-phase events produced an order of magnitude greater heat energy, and at 22 kA sustained arcing until interrupted by the test cell controller. Results suggest that 240 V single-phase panels and equipment common in residential and light commercial applications may be at very low risk of yielding arc flash burn-related injuries. However, 480 V single-phase faults can produce levels of incident heat energy known to cause burns, flash, and blast pressure at available fault currents between 10 and 22 kA.

中文翻译：

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箱内单相垂直导线的弧闪研究


NFPA 70E 和 IEEE 1584 正在定义电弧闪光危害分析的标准。两者都假设三相故障进行计算，因为三相配电在公用事业和工业应用中占主导地位；然而，单相系统中的电弧闪光被排除在外。中性点或接地的单相故障或单相间故障可能在多种情况下发生。此类事件可能会产生电弧闪光和爆炸，从而造成重大安全隐患。本文介绍了最近一项关于单相配置中电弧闪光的博士研究调查。实验由 UL 赞助，并在爱荷华州锡达拉皮兹的施耐德电气高功率实验室进行。该设施提供了测试物品；全套电压、电流和温度仪表；和高速视频录制。实验工作表明，240 伏单相电弧故障事件的入射能量值小于 0.2 cal/cm2，但仍然存在明显的闪光和熔丝残留物飞溅。 480 V 单相事件产生的热能高出一个数量级，并且在 22 kA 时持续产生电弧，直到被测试单元控制器中断。结果表明，住宅和轻型商业应用中常见的 240 V 单相面板和设备发生电弧闪光烧伤相关伤害的风险可能非常低。然而，480 V 单相故障会产生一定程度的入射热能，在 10 至 22 kA 的可用故障电流下会导致烧伤、闪光和爆炸压力。