1. Why does the compressor have to run continuously for at least 5 minutes and stop for at least 3 minutes after shutting down before restarting?
Stopping for at least 3 minutes after shutting down before restarting is to eliminate the pressure difference between the compressor inlet and exhaust. Because when the pressure difference is large, the starting torque of the motor will increase, causing the current to rise to a certain level, the protector will be activated, and the compressor cannot continue to run.
2. Confirmation of the position of the air conditioner filling fluorine
Refrigerant can generally be added in three places: condenser, the liquid storage side of the compressor, and evaporator.
When adding liquid at the liquid storage, when the system starts, the liquid refrigerant will continuously impact the cylinder, causing the compressor to produce liquid shock, which is extremely fatal to the damage to the compressor. At the same time, after the liquid refrigerant directly enters the compressor, it may adhere to the terminal, causing instantaneous insulation and poor withstand voltage; similarly, this situation will also occur when adding liquid on the evaporator side.
As for the condenser, due to its large volume, it can store a sufficient amount of refrigerant, and there will be no adverse consequences when starting, and the filling speed is fast and safe; so the method of filling liquid at the condenser is generally adopted.
3.. Thermal switches and thermistors for frequency conversion
Thermal switches and thermistors are not related to the compressor wiring and are not directly connected in series in the compressor circuit.
Thermal switches control the on and off of the compressor control circuit by sensing the temperature of the compressor cover.
Thermistors are negative temperature characteristic elements that have feedback signals output to the microprocessor. A set of temperature and resistance tables are pre-entered in the microprocessor. Each resistance value measured can reflect the corresponding temperature in the microcomputer. Ultimately, the temperature control effect is achieved.
4. Motor winding temperature
The operating conditions should be below 127°C at maximum load.
Measurement method: Within 3 seconds after the compressor stops, use a Wheatstone bridge or digital ohmmeter to measure the main winding resistance, and then calculate according to the following formula:
Winding temperature t℃＝[R2(T1+234.5)/R1]－234.5
R2: measured resistance; R1: winding resistance in cold state; T1: cold motor temperature
If the winding temperature exceeds the use conditions, the following defects may occur:
The aging speed of the winding enameled wire is accelerated (the motor burns);
The aging speed of the insulation material binding wire and the insulation paper is accelerated (the insulation life is halved for every 10℃ increase in temperature);
Oil deterioration due to overheating (lubricating performance decreases)
Guangxi Cooler Refrigeration Equipment Co.,Ltd
Email:karen@coolerfreezerunit.com
Tel/WhatsApp:+8613367611012
Post time: Oct-22-2024