| 摘要 |
PURPOSE:To make a bypass circuit for controlling the overload unnecessary and simplify the construction of a refrigerating cycle by a method wherein the overload control upon room heating operation and room heating touch defrosting operation is effected by the control of starting and stopping of an outdoor fan. CONSTITUTION:Upon the room heating operation, the flow of a refrigerant medium is recirculated through a compressor 21, a four-way valve 12, a first indoor heat exchanger 26, a two-way valve 28 for dehumidifying, the second heat exchanger 25, a pressure reducer 24 and an outdoor heat exchanger 23 sequentially. In this case, the outputs of respective transistor invertors (INV) 8-10 are H, L, L, respectively normally wheh the condition of a pressure switch 3 is as shown by the diagram, therefore, an outdoor fan motor 14 is rotated. Next, when it is turned into the overload condition, the contact piece 3a of the pressure switch 3 is switched to the side of a high-pressure contact 3c and said motor 14 is stopped. On the other hand, upon the room heating mode dehumidifying operation, the refrigerant medium flows as shown by the broken line arrow sign and the outputs of respective INV 8-10 are L, H, L, respectively, therefore, the fan motor 14 is controlled by a procedure in reverse to the above-described procedure. |
