| 摘要 |
PURPOSE:To permit employing both of single-phase and three-phase power source for the power supply of an outdoor machine by a method wherein the three-phase motor for heat exchanging fan is driven by three-phase AC power supply through a frequency converter constituted of a rectifying circuit, capable of inputting either one of single-phase or three-phase power, and an inverter, outputting three-phase power. CONSTITUTION:A power supply terminal block T is provided with a structure capable of connecting either single-phase power source or three-phase power source. Heat exchanging fan motors Ml, M2 and a driving motor PM for a cooling water pump 12 are constituted of AC three-phase motors. In this case, either one of single-phase 200V AC power supply or three-phase 200V power supply is passed through rectifying circuits 27, 28 once to convert AC power into DC power. Then, the DC power supply is converted into AC power supply again by inverters 18, 19. When power supply is converted into AC three-phase power supply by the inverters 18, 19, the number of rotation of the heat exchanging fan motors M1, M2 can be controlled by changing the frequency of AC three-phase power supply by a control signal from an outdoor machine control unit C. |
