Clause 3 – How to understand the definition of “class 0I appliance”

class 0I appliance: appliance having at least basic insulation throughout and incorporating an earthing terminal but having a supply cord without earthing conductor and a plug without earthing contact.

The appliance has a terminal for connecting an external protective conductor (protective earth conductor), but there is no wire for connecting the appliance to the protective conductor in the fixed wiring, the appliance may have a wire or construction inside for transmitting earth continuity.

In Japan, there is a plug specifically for class 0I appliances, as shown below.

From what I understand, at present, only Japan uses class 0I appliances. Usually, the supply cord have an earthing wire, but the earthing is not done by the earthing pin in the plug. Instead, tools are used to connect a separate terminal or earthing ring to achieve effective earthing. Correspondingly, there is also a earthing terminal on the appliance. Before installation, this terminal is not connected to any external wires and is usually connected during use and installation.