Controller and control method for refrigerating system

摘要

In a controller for a refrigerating system including refrigerating machines and showcases, a showcase that is about to execute a defrost operation is detected on the basis of a defrost operation indicating information. When the controller receives a notification indicating start of the defrost operation from the showcase concerned or on the basis of a comparison result between a pre-stored defrost-operation start time and the present time, at least one of the refrigerating machines is instructed to reduce the output power thereof. When the showcase finishes the defrost operation, the at least one of the refrigerating machines is instructed to increase the output power thereof so that the output power of the refrigerating machine is set to stationary output power.