Common problems and solutions to pre-cooling machines

　　The following are some common fault descriptions, troubleshooting methods and some solutions for vacuum precoolers compiled by the technical engineers of Ganzhou Dachang Air Conditioning Equipment Engineering Co., Ltd. for reference only. If you have any questions, please leave me a message or call our phone number!

　　1. The vacuum degree is not high

　　Possible reasons:

　　1. The pump itself is leaking: the sealing ring and gas ballast valve gasket are damaged or not tightened, and the exhaust valve piece is damaged, resulting in poor sealing.

　　2. The pump temperature is too high. It may be that the valve plate or inner cavity of the pump is scratched and worn, and the rotor axis is displaced, causing one-sided wear.

　　3. There is a problem with the pump oil: 1. The oil level is too low and the seal is not tight; 2. The oil is contaminated and turns milky yellow; 3. The oil level is normal, the oil circuit is blocked, and the appropriate amount of oil is not maintained in the pump cavity.

　　4. The air inlet filter of the vacuum cooler is blocked.

　　Troubleshooting methods and solutions:

　　1. Reassemble after repair.

　　2. Refuel; change the oil; check the oil pipeline and the oil intake of the oil valve.

　　3. Replace the sealing ring or valve plate according to the specific situation.

　　4. Remove and clean.

　　2. The motor is overloaded and there are abnormal noises during pump operation.

　　Possible reasons:

　　1. The filter is damaged and debris falls into the pump.

　　2. The pump cavity is seriously polluted and the parts are corroded.

　　3. The spring is deformed or broken, causing the rotary vane to receive uneven force and make impact sounds.

　　4. The pump chamber shaft and sleeve are too tight, causing poor lubrication.

　　5. The pump temperature is too high. It may be that the valve plate or inner cavity of the pump is scratched and worn, and the rotor axis is displaced, causing one-sided wear.

　　Troubleshooting methods and solutions:

　　1. Replace the spring.

　　2. Remove and clean.

　　3. Replace with special new oil.

　　4. Reassemble after repair.

　　5. Reassemble and clear the oil passage.

　　3. Vacuum cooler compressor oil leakage and oil injection

　　Possible reasons:

　　1. The air inlet pressure is too high.

　　2. Too much oil will cause fuel injection.

　　3. The oil screen under the exhaust cover is installed backwards, causing fuel injection.

　　4. The sealing rings on the rotating shaft, oil window, oil drain hole and other parts are damaged or incorrectly assembled.

　　Troubleshooting methods and solutions:

　　1. Try to reduce the amount of oil intake.

　　2. Release some of the oil.

　　3. Reassembly.

　　4. Replace the sealing ring or reassemble.

　　4. Maintenance of vacuum pre-cooling equipment

　　1. Before starting the unit, it is necessary to confirm that the four cutoffs on the pipeline connection are all in the fully open state. When the unit is started, observe the direction of the fan (if the fan is reversed, the two phase lines need to be replaced), the starting condition of the compressor (the pressure of the high-pressure gauge increases when starting the compressor, the pressure of the low-pressure gauge decreases, the temperature of the liquid pipe increases, and the temperature of the air pipe decreases), and whether there is any noise or abnormal vibration in the system.

　　2. If any abnormality is found during startup, you should shut down the machine immediately and determine the cause before handling it.

　　3. After the unit is put into operation, the operating current, high and low pressure of the compressor and fan should be regularly measured and observed, and records should be made in a timely manner for management and summary.

　　4. All electronic control components and protection devices of the unit have been strictly tested before leaving the factory. Users are advised not to change or remove them during inspection or maintenance. Forced operation without protection will definitely cause greater damage to the unit.

　　5. The following points must be done in daily maintenance to avoid possible failures and keep the unit operating normally and efficiently.

　　(1) The finned coil heat exchanger should be flushed regularly depending on the dust accumulation and contamination, and attention should be paid to electrical safety when flushing.

　　(2) Regularly check the current when the indoor centrifugal fan is running. For belt-driven centrifugal fans, regularly check the tightness of the belt.

　　6. Conduct regular inspections of the entire machine at least once a month, including whether the electrical circuits and components are loose, the operating sound of each part of the unit, whether there are leaks in the refrigeration system (observe the low-pressure gauge), whether the temperature probe and probe wires are intact, and whether the operating switch is loose.

　　7. When the unit shuts down due to a fault, first press the stop button of the unit (the alarm light will go out) and then check the cause of the fault. Do not force start until the fault is eliminated.

　　8. Unless it is an emergency, do not shut down the machine by cutting off the main power supply. If a short-term shutdown is required (less than 7 days), just press the shutdown button of the unit without turning off the main power supply. If the unit needs to be shut down for a long time, first shut down the unit, then turn off the main power supply, and drain the water in the system.

　　We will briefly introduce the common problems and solutions of precooling machines here. We hope it will be helpful to everyone. If you need more information, please contact our staff.

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