| 摘要 |
The present invention provides a screw compressor for refrigerating apparatus capable of controlling the rotational speed of a motor to be suitable for cooling heat load by simply controlling an inverter, without causing the overload of the motor.The screw compressor 1A for refrigerating apparatus 10A, which uses a motor 22 controlled by an inverter, as a driving portion, is provided with a suction pressure detector D3 as a heat load detecting means for detecting the cooling heat load; a motor coil temperature detector D1 as a means for detecting the load condition of the motor 22; and a controller 26 that decreases the rotational speed of the motor 22 if the capacity of the compressor is determined as excessive based on a pressure signal from the detector D3, maintains the rotational speed if the capacity is determined neither excessive nor lacking. In case that the capacity is determined as lacking, the controller 26 reduces the rotational speed if the load condition is determined as excessive based on a temperature signal from the detector D1 and increases the rotational speed in the other case.
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