Some small household appliances have no grounding wire.
The grounding wire is connected to the metal shell of the electrical appliance. When the electrical appliance leaks electricity, the current will be transmitted to the earth through the grounding wire, which will trip the leakage protector installed at the head end of the line, cut off the power supply of the electrical appliance and protect personal safety. The grounding wire is not charged, but it is repeatedly grounded at the entrance, and the grounding resistance is greater than 4 ohms.
The neutral line and the live line form a power supply loop.