class 2 and class 3

[Unregistered]

I am new thats electrical business , what is a class 2 product [ two wires and no earth ?] and is class 3 with three wires [ 3 core] with an earth.

Why do some items not require earth

What is the meaning of double insulation in laymans tearms [ does it mean two protective layers of inulstaion or reinforced inulstion aroud a conductor].

Thanks

 

[EasyFox]

Class 1 equipment has a protective earth & also relies on insulation between live parts & exposed conductive parts.

Class 2 equipment is either double insulation or reinforced insulation between live parts & conductive parts.

Class 3 equipment relies on the fact that no voltages higher than safety extra low voltage (SELV) are present, thats 25v ac & 50v dc.
Class 3 equipment is either supplied by a selv transformer or is battery operated.