CONTROL OF OIL HEATER

PURPOSE:To minimize the power consumption of an oil heater by controlling the circuit of the oil heater by a microcomputer when an operation stops and minimizing the electrifying time of the oil heater in a timer starting operation mode. CONSTITUTION:When a power supply is supplied to a controller 1, an oil heater 6 is electrified and an oil in a compressor is warmed. When an air conditioner operating switch is closed, an output relay 11 for a blower and an output relay 12 for a compressor are closed, the contacts 3a and 5a of magnetic contactors are closed and the compressor 2 and the blower 4 are operated. Further, an output relay 14 for the oil heater is opened, and electrification of the oil heater 6 is stopped and the temperature of the oil in the compressor 2 is maintained by a high temperature refrigerant gas. The output relay 12 for the compressor is closed only when the temperature signal value of a room temperature thermistor 11 is higher than the set signal value of a room temperature setting device 9 and, in a reverse case, the output relay 12 for the compressor is closed and the output relay 14 for the oil heater is also closed whereby the compressor 2 is stopped and the oil heater 6 is electrified.