Reasons and Correct Treatment Methods for Burning Refrigeration Compressor Coils
Compressor coil burn-in can be divided into mechanical failure and gas failure. Common reasons for electrical faults to burn compressor coils are: load, power supply, motor insulation, phase loss......
1. Common causes of compressor coil burnout (electrical part)
1. Lack of phase
Reason: It is generally caused by the lack of phase of the power supply (one phase is not powered or the power supply voltage is insufficient) or the contact point of the contactor in the line is not closed, the connection point of the wire is disconnected, loose or the contact position is oxidized. The lack of phase is characterized by the fact that one or two phases (level 4) in the windings all turn black, the coil is damaged symmetrically, and there are rules for lack of phase.
Reasons and Correct Treatment Methods for Burning Refrigeration Compressor Coils
2. Overload
Reason: Generally, the motor runs over-current for a long time, runs overheating, starts or brakes frequently, and wiring errors are also caused (delta connection into star connection). The overload is characterized by the windings all turning black, the end straps discoloring and becoming brittle or even breaking.
Reasons and Correct Treatment Methods for Burning Refrigeration Compressor Coils
3. Between turns
Reason: The enameled wire is broken during the motor manufacturing process, and the moisture, acid, and other corrosive substances in the system will also cause such failures. The inter-turn feature is that the winding is partially blown. Usually, when the inner cavity of the motor is clean, there is only one explosion point.
4. Alternate
Reason: The interphase paper is not in place, or the interphase paper (casing) is damaged. Phase-to-phase characteristics: The motor is burned between two adjacent phases.
Reasons and Correct Treatment Methods for Burning Refrigeration Compressor Coils
5. Ground Strike
Reason: The distance between the coil and the end cap frame is not enough. Ground strike is characterized by black burn marks in both places between the coil and the end cap or end cap.
Second, the treatment method after the compressor coil is burned
If the compressor has been burnt or mechanical failure or wear, it will cause inevitable pollution of the refrigerant system. In this case, the refrigeration system should be treated. If the system is not treated, the refrigerant will be completely replaced within 0.5-1 hour after the compressor is replaced directly. After contamination and impure refrigeration oil, it begins to destroy the original lubricating properties. Metal dirt powder entering the compressor may break through the motor insulation film and short-circuit, and then burn out, resulting in increased friction between the shaft and the shaft sleeve or other running parts, and the machine will be killed. This is also the reason why the new compressor burns out in about a month.
Correct handling method:
If the compressor motor has been burnt and cannot run, and the machinery is not known, the treatment method:
Method 1: If the oil and refrigerant are smelly, burnt, spicy, and the oil is black like black ink, the inside of the tube is full of dirty black film, and there will be moisture. The dryer can be removed, short-circuit this part to a copper pipe joint or a temporary detachable pipe. Use a chemical pump to pump the cleaning agent into the pipeline system from a high-pressure pipe to clean and circulate.
Method 2: Remove the dryer and blow through the entire pipeline with high-pressure nitrogen gas at a pressure of about 10KG. Replace the dryer with a new one, detect leaks in the whole system, and pump vacuum from the high and low pressure ends at the same time.
The liquid refrigerant is added from the liquid pipe part to reach 70%~80% of the refrigerant volume before starting the test. After running for about half an hour after starting, replace the dryer and observe its fouling condition. The second new dryer must run for another 3 hours, observe the results, and replace it if necessary until the system is completely clean. Finally, change the refrigeration oil of the compressor and observe the new oil for the first time.
Note: When replacing the dryer above, do not allow air to enter the system. In severe cases, the compressor must be removed to change the oil, and all the refrigerants must be released and replaced.
