me_chkaa：
據我所知,UL的標準里,關于enclosure的要求,都統一跟從UL746C(可能一些與IEC合并的標準例外).根據UL746C,凡>42.4Vpeakvoltage(30VRMS)的電壓都視為可能導致著火或觸電.3.34RISKOFELECTRICSHOCK–Ariskofelectricshockisconsideredtoexistatanypartif,a)Thepotentialbetweenthepartandearthgroundoranyotheraccessiblepartismorethan42.4Vpeak,andb)Thecontinuouscurrentflowthrougha1500ohmresistorconnectedacrossthepotentialexceeds0.5mA.3.35RISKOFFIRE–Ariskoffireisconsideredtoexistatanytwopointsinacircuitwhere;a)Theopencircuitvoltageismorethan42.4Vpeakandtheenergyavailabletothecircuitunderanyconditionofloadincludingshortcircuit,resultsinacurrentof8Aormoreafter1minuteofoperation,orb)Apowerofmorethan15wattscanbedeliveredintoanexternalresistorconnectedbetweenthetwopoints.