What is the difference between mechanical temperature control and electronic refrigeration of refrigerator?

Refrigerator inspection should follow the principle of from the outside to the inside. The first is the appearance. After determining the model of the refrigerator, you can observe whether the color of the refrigerator meets the requirements, whether the surface is smooth and smooth, and there is no scratch or looseness. The inner cavity should be smooth, free from cracks and bubbles, uneven, peculiar smell and serious stains. The periphery of the box and the door should be straight, the assembly should be firm, the door should not be skewed, and the clearance between the rotating shaft and the shaft pin should be well matched. Foam liquid should not leak at the contact points of doors, boxes and door openings.

After electrifying, according to the expert's suggestion, seven tests can be used to detect the "inside" of the refrigerator.

First, check the door. When closing the door, close to the door frame, due to the attraction of the magnetic stripe, the door will automatically close, and there should be no gap.

Secondly, check the compressor. When the power supply is connected, the refrigerator can be started immediately and enter the running state; When the power is cut off, the refrigerator stops normally; When starting again, the compressor should be able to start and run normally within one second.

Third, check the "movement". After the compressor is started, the refrigerator will vibrate slightly, resulting in operating noise, which should not be higher than 45 decibels, that is, in a quiet environment, only a slight hum of the compressor can be heard, and no sound should be heard at a distance of about one meter from the refrigerator. There should be no obvious vibration when touching the box.

Fourth, check the lighting. When you open the refrigerator door, the lights in the refrigerator will turn on, and when the door is close to the full closed state, the lights will go out.

Fifth, check the refrigeration. After the refrigerator starts running for 5 minutes, touch the condenser of the refrigerator (both sides or back of the refrigerator) with your hands, and you should feel hot. The sooner you heat it, the better. When opening the refrigerator door, touch the evaporator with your hand, you should feel cold; Close the door for about 20 minutes, and the condenser is already very hot. Open the door and check the evaporator carefully. There should be a thin and even layer of frost on it. If the frost on the evaporator is uneven or there is no frost on a certain part, it means that the refrigeration performance of the refrigerator is not good. Consumers can put a few cups of cold boiled water in the refrigerator and adjust the refrigerator to "quick freezing" state, and test the quick freezing ability and compressor performance of the refrigerator through freezing time and efficiency.

Sixth, check the temperature control. When the thermostat is set to the stop position, the compressor should stop running immediately; Adjust to the strong cold position and keep the compressor running; After a period of normal operation, the refrigerator should be able to start and stop automatically at a certain time interval. At this time, the temperature of the refrigerating room shall not be higher than 5℃, and the temperature of the freezing room shall conform to the star-rated regulations; Under normal circumstances, the number of compressor starts should not exceed 6 ~ 9 times per hour.

Seventh, check whether the indoor temperature of the refrigerator is not higher than 10℃ and the indoor temperature of the refrigerator is -5℃ and below, and whether it will stop automatically.

Preservation is also a key index of refrigerator performance. You can put some apples in the refrigerator and observe the preservation of apples after two days. Although this item can't be carried out in time when the goods arrive, it can at least avoid consumers from suffering losses because they know.