2. Look at the plug.
There are three wires at the other end of the plug. Live wire, neutral wire and ground wire are distinguished by wiring color.
Three-wire plug is live wire, neutral wire and ground wire. Three-wire plug can better protect the safety of household appliances with metal shell and reduce leakage and electric shock accidents.
Extended data three-phase electricity refers to three live wires with different phases, and the voltage between each two wires is 380 volts. Generally used in power systems. Single-phase power supply is generally used in household appliances, and its three wires are live wire, neutral wire and ground wire. The voltage between the live wire and the neutral wire is 220 volts, so this is not three-phase electricity.
References:
Baidu encyclopedia-three-wire plug