Reconstruction and fire risk assessment of arc-tracking at a plug-outlet connection point
Reconstruction and fire risk assessment of arc-tracking at a plug-outlet connection point
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插头插座连接点电弧痕迹重建及火灾风险评估
DOI：
10.1002/fam.3056
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发表时间：
2022
影响因子：
1.9
通讯作者：
Masakatsu Honma
中科院分区：
文献类型：
--
作者：
katsuhiro Okamoto;Masahiro Nakagawa;Jumpei Fujimoto;Toshikazu Ichikawa;Hiroki Yamasaki;Nobuyuki Kashiwagi;Masakatsu Honma
聚氯乙烯（PVC）是一种典型的插头绝缘材料，是一种具有高耐漏电起痕性的有机材料。然而，PVC的耐漏电起痕性由于热降解而大大降低。在本研究中，将具有低漏电起痕电阻的酚醛树脂作为绝缘材料植入插头叶片之间，模拟插头的热降解绝缘材料，并提出了一种可以有效可靠地重建电弧起痕的方法。此外，使用所提出的方法进行电弧跟踪实验，以评估电弧跟踪引起的插头插座连接处的火灾风险。为了重建绝缘故障的最终状态，其中插头绝缘材料的漏电起痕电阻由于热降解而劣化，切断额定值为12 A、125 V的PVC插头的叶片之间的绝缘材料。然后，将酚醛树脂片（6或3mm宽）植入插塞叶片之间的整个上半部或下半部中。通过在酚醛树脂表面涂敷碳脂，加速了绝缘失效的最终状态。将植入的插头插入连接100 V AC商用电源的15 A、125 V额定插座中，观察到插头插座连接处的电弧痕迹。当待植入的酚醛树脂的宽度为3mm时，我们发现，由于较长的放电持续时间，出口板和插头可以点燃。由于PVC的自熄特性，火花塞通常在放电结束后立即熄灭，但当丙烯腈丁二烯苯乙烯树脂出口板点燃时，燃烧持续了几分钟。尽管PVC具有自熄特性，但它们在电弧跟踪过程中会暂时燃烧。从结果来看，从电气火灾爆发的火焰被认为蔓延到出口板，并最终发展成为火灾。
Polyvinyl chloride (PVC), a typical plug insulating material, is an organic material with high tracking resistance. However, the tracking resistance of PVC gets considerably reduced by thermal degradation. In this study, a phenol resin with low tracking resistance was implanted between plug blades as an insulating material that simulated the thermally degraded insulating material of the plug, and a method that could efficiently and reliably reconstruct the arc‐tracking was proposed. Also, arc‐tracking experiments using the proposed method were conducted to evaluate fire risk at the plug‐outlet connection caused by arc‐tracking. To reconstruct the end state of insulation failure in which the tracking resistance of the plug insulation material deteriorated due to thermal degradation, the insulation material between the blades of a 12 A, 125 V rated PVC plug was cut out. Then, a phenol resin piece (6 or 3 mm width) was implanted in the entire, upper or lower halves between the plug blades. The end state of insulation failure was accelerated by applying carbon grease to the phenol resin surface. The implanted plug was inserted into a 15 A, 125 V rated outlet connected to a 100 V AC commercial power supply, and the arc‐tracking at the plug‐outlet connection was observed. When the width of the phenol resin to be implanted was 3 mm, we found that the outlet plate and plug could ignite due to the longer electrical discharge duration. The plug was often extinguished immediately after the end of the electrical discharge due to the self‐extinguishing properties of PVC, but when an acrylonitrile butadiene styrene resin outlet plate ignited, the combustion continued for several minutes. Even though PVCs have self‐extinguishing properties, they burn temporarily during arc‐tracking. From the results, the flame from the electric fire outbreak is believed to spread to the outlet plate and eventually developed into a fire.