影印機為火災起火源之可能性分析

Analysis on Possibility of Photocopier as Ignition Source

本事件經火災鑑定委員判定影印機為起火點，本研究以實驗之方式證明影印機並非起火 點。地方法院亦依本實驗鑑定報告判定其非起火點。證明以實驗數據佐證火災爆炸鑑定之重要 性。其中本研究之實驗發現，當影印機內部電源線發生電線負載、電線短路時，並不會引燃影 印機內部其他電線或是影印機之塑料外殼甚至是影印機周圍紙張等物品，證明不同披覆材料之 電線，發生過負載之現象並不相同，研究結果發現某日本影印機所使用之難燃電線經過負載高 電流通電後，內部銅線燒斷但其披覆僅發生熱膨脹及龜裂的現象，並未因高溫而起火燃燒；相 對於一般家用常用電線（同樣為16AWG）則承受不了高溫整條電線起火燃燒，由此可知其電 線披覆材料設計之重要性。當影印機周圍擺設如汽油等易燃性液體，使其影印機內部發生過負 載，不管內部電源線材質為何材質，皆會將汽油引燃。結果亦顯示，易燃性液體與影印機等電 器設備需有適當的安全距離因而不可擺設太近。

This case had been judged by the fire assessment committee that the photocopier was the ignition point; and the court of first instance determined it not to be the ignition point based on the report of this research. This case showed that the experiment data are very important to prove the fire origin during fire investigation and this research discovered that neither overloading nor short-circuiting of the cables of the photocopier would result in ignition of the wire on the interior, the plastic casing, or the paper around the photocopier. When using cables with various coatings, the results caused by overloading were drastically different. Under an overload to the cables of a Japanese photocopier, the copper interior snapped and the outer coating only expanded and cracked, but there was no fire nevertheless the high temperatures. In contrast, when using standard household cables (16AWG), they could not withstand the high temperatures and ignited, which explains the importance of the design for the outer coatings of electric cables. When combustible liquids such as gasoline were placed beside the photocopier, the gasoline would ignite if the photocopier was overloaded regardless of the type of outer coating. Results show that combustible liquids should be placed at a safety distance from electric appliances such as photocopiers