| 摘要 |
PROBLEM TO BE SOLVED: To prevent a liquid compression at the time of starting a compressor by energizing a crankcase heater at the time of turning ON a power source in a prefabricated refrigerator with a deep freezer having the freezer with the heater at the compressor, and starting the compressor after a predetermined time is elapsed. SOLUTION: When a serviceman closes a power source ON switch 30 after an installation of the prefabricated refrigerator with a deep freezer, a crankcase heater 25 is energized through a normally closed type contact 32b of a magnet switch 32. When a predetermined time is elapsed after the switch 30 is closed, a contact 34a of a delay timer 34 is closed, the contact 32b is opened, the heater 25 is deenergized, a normally closed contact 32a of the switch 32 in a cable 29 is closed, and a motor 22b is started. At the time of energizing the power source in this manner, the heater 25 is energized to raise an oil temperature in the crankcase of the compressor to a predetermined temperature or higher, thereby preventing a liquid compression at the time of starting the compressor. |
