heating operation is more than 50nzin. When these two conditions are met at the same time, the supermarket display cases main control circuit board issues an instruction to stop the indoor fan, the four-way valve is de-energized, and the V line voltage becomes zero, so the coil of JI is energized and the normally closed contact of J1 Disconnect to stop the outdoor fan. At this time, only the compressor is working, and the supermarket display cases enter the defrosting operation. When the temperature of the outdoor heat exchanger pipe rises to reset the defrost controller, or the defrosting operation time is more than 10 minutes, the main control circuit board sends out a command, the room cliff runs, the four-way valve is energized, the outdoor fan also runs, and the air conditioner Start heating operation.

　　 The display cases of supermarkets must be grounded reliably. At present, public grounding wires are generally installed in newly-built buildings, or the power supply department has specially designed   protection and zero   wires. Users of this kind of building only need to plug the three-pin plug of the supermarket display cases power cord directly into the three-pin socket. Old-fashioned buildings generally do not have a ground wire, and you must install the ground wire yourself. Users who live on the first floor can use 40mmX4mm flat steel or 50nunX50mmX4nun angle steel, buried in the ground about lm deep, lead into the room with a grounding wire, and install a three-core socket. If you live in a high-rise building, you can use the metal pipe of tap water as a safety grounding protection. The grounding wire drawn from the water pipe should be fastened to the water pipe with a wiring clip to ensure good conduction. Drain pipes, heating pipes and gas pipes must never be used as grounding wires.

　　 pressure controller is also called pressure relay, it monitors the high pressure of condensation and low pressure of evaporation in the refrigeration equipment system in supermarket

display cases (including the oil pressure of oil pump). The head cuts off the power supply and the compressor stops working for protection and control. The remote control signal receiver is installed in the panel of the air conditioner. After the infrared command signal is received by the receiver's photodiode, the supermarket display cases phototube converts the light signal into an electrical signal. After the signal is amplified, limited, filtered, detected, shaped, and decoded, it is output to the relevant circuit to perform the corresponding function. This article is provided by refrigerated showcase display cases net