| 摘要 |
PURPOSE:To prevent the over-increase of temperature of a main transistor in the inverter by a method wherein a radiating plate for the main transistor in the duct of a cooling fan is cooled forcibly by air and a control circuit, never stopping the operation of the cooling fan even after a thermal safety device is operated, is provided. CONSTITUTION:The cooling fan 2 and the main transistor 3 are in an outdoor unit 1 and the main transistor 3 is provided with a radiator 4 and a temperature sensor 5 while the heat dissipating fan of the radiator 4 is provided at the side of the duct of the cooling fan. A microcomputer, effecting digital operation process by a preset program, is used for the control. Once the temperature of the main transistor has arrived at a set temperature and a main transistor temperature over-increase plug is set, the operation of the inverter is stopped to protect the main transistor from the over-increase of the temperature but the operation of the cooling fan is continued to cool the main transistor forcibly, therefore, the temperature of the main transistor may be reduced rapidly. |
