IEC60335系列标准中,60335-2-15特标中有这么一段:
Portable appliances having a rated current of up to 10A may incorporate a supply cord having a
nominal cross-sectional area of 0.75mm2 if the length is less than 2m.
Kettle supply cord, other than those helically coiled, shall not be longer than 75cm.
但是UL标准中有很多明确指出电源线的长度至少为6~9英尺。