[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-108-1-fire-science-033":3},{"subject":4,"subjectSlug":5,"subjectKicker":6,"subjectShort":7,"question":8,"related":27,"sameNumber":52,"hasEssay":26},"火災學概要","fire-science","火災學 · Fire Science","火災學",{"id":9,"webId":10,"year":11,"session":12,"subject":4,"number":13,"stem":14,"options":15,"answer":20,"answerNote":21,"images":22,"imagesPending":23,"lawTimestamp":11,"explanation":24,"explanationDeep":25,"freq":12,"indexable":26},"fire-108-1-火災學概要-033","fire-108-1-fire-science-033",108,1,33,"電氣火災中，下列何者為積污導電現象？",{"A":16,"B":17,"C":18,"D":19},"承受直流電壓之含銀異極導體間，其絕緣物表面附著水分，陽離子沿絕緣物表面移動至陰極，產生電流流通而發熱","木材、電木等絕緣體之絕緣性受到破壞，而導致異常電流流通","絕緣物內存有瑕疵，如氣隙、雜質等，在承受高電壓下，造成電場不均而破壞絕緣性","異極導體間之絕緣物表面附著水分及灰塵，在承受電壓下造成絕緣物表面流通電流而發熱","D",null,[],false,"本題考點：電氣火災各種發熱現象的定義辨識，重點在區分積污導電(tracking)、銀離子移行、絕緣劣化與內部局部放電。\n【正解理由】積污導電又稱表面漏電或 tracking,定義是異極導體之間的絕緣物「表面」附著水分與灰塵等導電性污染物，在持續電壓作用下沿表面形成微小漏電流並發熱，局部乾燥後產生小火花，反覆閃絡使表面碳化，碳化路徑逐漸連通而演變成短路起火。此定義與 (D) 敘述完全相符，故選 D。\n【逐項排除】\n(A) 描述直流電壓下含銀導體的銀離子沿吸濕表面向陰極移動並析出，這是銀離子移行現象，與灰塵無關，並非積污導電。\n(B) 木材、電木等絕緣體本體絕緣性被破壞而流通異常電流，屬絕緣劣化與導電化(石墨化)現象，發生位置在材料內部而非表面污染層。\n(C) 絕緣物內部存在氣隙或雜質，高電壓下電場集中而破壞絕緣，屬內部局部放電與樹枝狀劣化，是內部缺陷問題。\n(D) 表面附著水分與灰塵、承受電壓後表面流通電流並發熱，正是積污導電的教科書定義，為本題應選者。\n【記憶點】積污導電看四字：表面、污染、漏電、碳化。","電氣火災的起火型態通常分為短路、過負載、接觸不良(半斷線與接觸電阻發熱)、漏電、積污導電、銀離子移行與絕緣劣化等類型，國考幾乎年年在這組定義上出辨識題，關鍵是抓住「發生位置」與「觸發條件」兩個變因。\n\n積污導電的完整歷程可拆成四階段:①插座、端子等異極導體間的絕緣表面長期附著灰塵、纖維、鹽分 ②吸濕後形成導電性污染層，產生微小漏電流 ③電流使局部水分蒸發乾燥，乾燥帶兩端電位差集中而閃絡出小火花 ④火花使有機絕緣物碳化，碳化痕(tracking)逐次延伸，漏電流隨之增大，最終形成穩定電弧或短路而起火。因此它是一種「時間累積型」火災，常見於長期插著不拔的插頭、廚房與浴室等高濕高塵環境，且斷電後現場多可觀察到樹枝狀碳化痕跡，是火災調查的重要跡證。\n\n易混淆對照：銀離子移行需要直流電壓、含銀電極與水分，不需要灰塵，常見於印刷電路板與接點；積污導電交流直流皆可發生，但必須有表面污染物。內部局部放電發生在絕緣體「內部」的氣隙，屬高電壓設備的劣化型態；導電化(石墨化)則是木材、電木在反覆電弧作用下表面碳化成低電阻的石墨質路徑。\n\n相關考點連結：同組概念也常以「防止對策」的形式命題，例如保持插座清潔乾燥、採用具絕緣套與防塵蓋的插頭、選用耐漏電起痕指數(CTI)較高的絕緣材料等，都是針對表面污染與碳化路徑而設計的。判讀題幹時，只要看到「表面」加「水分與灰塵」兩個關鍵詞同時出現，答案幾乎必定指向積污導電。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-108-1-fire-science-032","下列有關防止靜電災害的方法中，何者錯誤？",32,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-108-1-fire-science-034","化學物質災害搶救程序 H.A.Z.M.A.T.中有關區域管制事項，下列敘述何者正確？",34,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-108-1-fire-science-031","假設建築物外部風速為 V 時，其迎風面的風壓為 P，當風速提高為 2V 時，建築物所受風壓變為：",31,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-108-1-fire-science-035","為避免液化石油氣儲槽因外圍起火燃燒，一時無法撲滅而發生 BLEVE 現象，可採取之防救策略下列何者正確？",35,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-108-1-fire-science-030","下列何種措施，可以防止由大樓窗口噴出的火焰向上層延燒？",30,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-108-1-fire-science-036","下列何者不是 IG-541 氣體滅火藥劑的成分？",36,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-113-1-fire-science-033",113,"對於金屬鈉的敘述，下列何者錯誤？",{"webId":58,"year":59,"stem":60,"number":13},"fire-112-1-fire-science-033",112,"當防火門兩側的壓力差加倍時，其透過門縫所流出的氣體體積流率有何變化？",{"webId":62,"year":63,"stem":64,"number":13},"fire-111-1-fire-science-033",111,"執行危害性化學品災害搶救指導原則（HAZMAT），下列有關區域管制（Zoning）敘述何者錯誤？",{"webId":66,"year":67,"stem":68,"number":13},"fire-110-1-fire-science-033",110,"當一小爆炸發生時，其壓力波將全廠之粉塵揚起，再被隨後而至之燃燒引爆所引起之全廠性爆炸，此現象為何？",{"webId":70,"year":71,"stem":72,"number":13},"fire-109-1-fire-science-033",109,"乙醇之燃燒化學反應式為下列何者？ 9 3",1785129967642]