Clause 3 – How to understand the definition of “class II construction”
The emphasis here is on a part of the construction on the appliance, which can meet the requirements of double insulation or reinforced insulation. Therefore, a class I appliance will also contain a class II construction .
Example: The oven shown in the figure below uses a metal shell and a plastic switch knob. When the user touches the switch knob, the knob is made of insulating material and cannot be grounded. The protection against electric shock can only rely on the insulation of the knob itself. There is basic insulation between the live parts inside the switch and the switch knob shaft, and the switch knob forms supplementary insulation. Therefore, the switch knob position is a class II construction.
