一类灯与二类灯的最大区别是在那里?
一类灯与二类灯的最大区别是在那里?也就是比较明显, 你可以看看一类灯与二类灯的定义就知道了。。。。 一类灯基本绝缘带地线, 二类灯双重绝缘不带地线 1.2.23class II luminaire
luminaire in which protection against electric shock does not rely on basic insulation only, but in
which additional safety precautions such as double insulation or reinforced insulation are
provided, there being no provision for protective earthing or reliance upon installation
conditions.
NOTE 1 Such a luminaire may be of one of the following types:
a) A luminaire having a durable and substantially continuous enclosure of insulating material which envelopes all
metal parts with the exception of small parts such as nameplates, screws and rivets which are isolated from live
parts by insulation at least equivalent to reinforced insulation. Such a luminaire is called an insulation encased
class II luminaire.
b) A luminaire having a substantially continuous enclosure of metal, in which double insulation is used throughout,
except for those parts where reinforced insulation is used because the application of double insulation is
manifestly impracticable. Such a luminaire is called a metal-encased class II luminaire.
c) A luminaire which is a combination of types a) and b) above.
NOTE 2 The enclosure of an insulation-encased class II luminaire may form a part or the whole of the
supplementary insulation or the reinforced insulation.
NOTE 3 If earthing is provided to assist starting, but is not connected to an accessible metal part, the luminaire
may still be deemed to be of class II. Accessible metal parts in compliance with the appropriate IEC lamp
specification and other metal parts not normally earthed and not normally accessible during normal use are not
regarded to be conductive parts which may cause an electric shock unless the tests of Annex A show them to be
live parts.
NOTE 4 If a luminaire with double insulation and/or reinforced insulation throughout has an earthing terminal or an
earthing contact, it is class I construction. However, a fixed class II luminaire intended for looping-in may have an
internal terminal for maintaining the electrical continuity of an earthing conductor not terminating in the luminaire,
provided that the terminal is insulated from accessible metal parts by class II insulation.
NOTE 5 Class II luminaires may have parts in which protection against electric shock relies on operation at safety
extra-low voltage (SELV).
1.2.24
class III luminaire
luminaire in which protection against electric shock relies on supply at safety extra-low voltage
(SELV) and in which voltages higher than those of SELV are not generated.
NOTE A class III luminaire should not be provided with means for protective earthing. 简单的看输入电源线三芯的是一类灯(即有接地线的). 没错, 它的电线标都不一样 II类必须有“回”标志。
页:
[1]
