Double insulation

Electricity. Electronic devices are usually equipped with basic insulation to prevent electric shock. Some devices are additionally equipped with supplementary insulation in case the basic insulation is damaged; this is called double insulation. Double insulation is often applied to devices with a high risk of electric shock due to leakage current caused by water or dust.

For electrical devices that require grounding, double insulation can reduce the risk of electric shock, which may allow for the omission of grounding. According to electrical equipment technical standards, electrical appliances that are constructed with double insulation as defined by the Electrical Appliance and Material Safety Act may omit grounding installation.