PURPOSE: To prevent the occurrence of a defreezing accident when a freezing refrigerating unit for a prefabricated refrigerating warehouse for cold-insulating and preserving foods is used.
CONSTITUTION: In a freezing cycle having a compressor 1, a condenser 2, a vaporizer 5, and a pressure reducing device 4, a bypass pipe is installed between the refrigerant outlet side of the compressor 1 and the inlet of the vaporizer 5 and an openable solenoid valve 7 for defrosting and a temperature detecting end 9 are arranged in the bypass pipe. By comparing a detecting temperature with an abnormality decision temperature, abnormality is automatically detected. Since abnormality in a solenoid valve for defrosting is properly detected after completion of defrosting, heating operation is prevented from being carried out, and a defreezing accident in a refrigerating warehouse is prevented from occurring. Further, since a failure in operation mode is displayed on a remote controller, a service after an accident is facilitated.
SASADA TAKESHI
IKEDA TAKASHI
TAKEDA TEI
ISHII RYUTARO
HITACHI SHIMIZU ENG KK