Types of insulation – Class I, II, III

What are the different types of insulation? (Class I, II, III)

Whatever national standard regulation or region standard regulation, the standard of leakage current is different by the insulation types of products. “CLASSI, II, III” are mainly in consideration of the insulation system of product which derived from IEC system, brief descriptions are as below:

CLASS I indicates anti-shock protection of product not only depends on basic insulation but also includes grounding method.
CLASS II indicates anti-shock protection of product not only depends on basic insulation but also includes additional precaution. For example double or reinforce insulation but without grounding or installation condition for relying precaution.
CLASS III indicates anti-shock protection of product depends on power voltage is safety extra-low voltage (SELV) and it don’t generate danger voltage.