Interface architecture for networked home appliance using plc technology

PURPOSE: A PLC(Power Line Communication) system for household appliances and a method therefor are provided to reduce unnecessary transmission quantity in a PLC network by preventing that power is supplied to an external PLC modem when the power is not supplied to the household appliances. CONSTITUTION: An external PLC modem(100) has the first power supply connector(110) and the first serial port connector(120). A household appliance(200) has the second and third power supply connectors(210,230) and the second serial port connector(220). The first serial port connector(120) and the second serial port connector(220) are connected each other. The first power supply connector(110) and the second power supply connector(210) are connected each other. The third power supply connector(230) is connected with the second power supply connector(210). The third power supply connector(230) is connected with a PLC network.