Safety extra low voltage

xshrmm

请教一个问题：

在IEC60598-1(2008)中，SELV(Safety extra low voltage)定义如下：
ELV in a circuit which is insulated from the mains supply by an insulation not less than that between the primary and secondary circuits of a safety isolating transformer according to IEC 61558-2-6 or equivalent.

NOTE Maximum voltage lower than 50V a.c. r.m.s. or 120V ripple free d.c. may be specified in particular requirements, especially when direct contact with current-carrying parts is allowed.

请问应该如何理解？灯具在什么情况下才能算是安全特低电压的灯具呢？

xshrmm

另外一个问题，安全特低电压是否人体可以接触？即在设备漏电的情况下，人体接触不会产生危险？