In class II products, the live parts are protected from access by basic and supplementary insulations. By definitions, supplementary insulation denotes an independent insulation applied in addition to basic insulation in order to provide protection against electric shock in the event of a failure of the basic insulation. That means the product is safe if the live parts are protected by a basic insulation and the supplementary insulation is another safeguard in the event of a failure of the basic insulation.
Can anyone tell me the background and when to raise this safeguard, supplementary insulation, in current safety standards. Your advice is most appreciated. Raymond Li
