| 摘要 |
PURPOSE:To reduce an insulation deterioration in a compressor motor in a preliminary heating device in which an open phase operation of the compressor motor is effected for an air conditioner by a method wherein the phases for performing an open phase operation are changed over in sequence. CONSTITUTION:A micro-computer for controlling an inverter device is provided with an inter-UV preliminary thermal output part 1, an inter-VW preliminary heating output part 2 and an inter-MU preliminary heating output part 3. They are changed over in sequence by a preliminary heating control part 4, currents flowing to each of the phase of the compressor motor are made uniform to cause a life of the compressor motor to be extended. |
