Why does the compressor burn the motor? What is the cause of the burning phenomenon? The causes of motor burning can be summarized as follows: load, power supply, motor insulation and lack of equality.
1.The common causes of compressor motor burning
First.lack of phase
Reason: Generally, it is caused by the lack of power supply phase (one phase is not powered or the power supply voltage is insufficient) or the contactor contact point in the line is not closed, the wire connection point is disconnected, loose or the contact point is oxidized.
Features: One phase or two phases (Grade 4) in the winding are all black, the winding is damaged symmetrically, and there are rules for missing phases.
2. Overload
Cause: Generally, the motor runs over-current for a long time, overheating, frequent starting or braking, and wiring errors also lead to (delta connection into star connection).
Features: All windings turn black, and the end cable ties change color and become brittle or even broken.
3. Interturn
Cause: The broken skin of the enameled wire caused by the motor manufacturing process, and the moisture, acid and other corrosive substances in the system can also cause such failures.
Features: The winding is partially burnt out, usually the motor cavity is clean, and there is only one explosion point.
4. Alternating
Cause: The interphase paper is not put in place, or the interphase paper (sleeve) is damaged.
Features: The motor burns between two adjacent phases.
5. Ground strike
Cause: The climbing distance between the coil and the end cover base is not enough.
Features: There are black marks between the coil and the end cover or the end cover.
2.The compressor after burning treatment method
1. If the compressor has been burnt out, mechanically broken down or worn out, it will inevitably pollute the refrigerant system. The situation is as follows (the system has a bad smell in the following cases, and you can know it by smell):
Residual refrigeration oil is carbonized, acid-containing and dirty in the tube.
After the compressor is dismantled, the original system pipe will be corroded by air, which will cause condensation effect, increase the residual water, and cause fouling film after corrosion with copper pipes and parts on the pipeline, which will affect the operation function of the new compressor next time.
The worn copper, steel, and alloy powder must have partially flowed into the pipeline to block part of the small tube channels.
2.The results of directly replacing the system with a new compressor are as follows:
It is impossible to completely vacuumize, and the vacuum pump is easily damaged. After adding new refrigerant, the refrigerant only plays the role of cleaning system parts, and the pollution of the whole system still exists.
The new compressor, refrigeration oil and refrigerant were all polluted within 0.5-1 hour immediately. After the refrigeration oil was impure, it began to destroy the original lubricating properties. Metal dust powder entering the compressor may break through the insulation film of the motor and short circuit, and then burn, resulting in increased friction between the shaft and the sleeve or other running parts, and mechanical seizure.
After the mixture of refrigerant, oil, original pollutants and acidic substances, more acidic substances and water will increase, and the phenomenon of copper plating will begin, the mechanical gap will be reduced, and the friction will increase and it will be stuck.
If the original dryer is not replaced, it will release the original water absorption and acidic substances. Acidic substances will gradually erode the surface insulation film of motor enameled wire.
Under the above conditions, the new compressor will be completely burned in about 1 month! !
Processing flow:
1. How to deal with the refrigerant system of a main engine whose compressor has burned out or failed? Compressor is damaged, of course, it needs to be replaced, and it is urgent, but before taking action to prepare materials and tools, the following work should be done well:
Whether the contactor, overload and temperature controller in the control box have quality problems must be checked and confirmed to be no problem.
Whether various set values have been changed, and analyze whether the compressor is burned due to the change of set values or wrong adjustment.
Check the abnormal condition on the refrigerant pipeline and correct it. Make sure that the compressor is burnt or stuck, or half burnt.
Measure the insulation with a shaking table and the coil resistance with a triple meter. Talk to the relevant personnel of the user to understand the general situation of the cause and effect as a reference for judgment.
Try to drain the refrigerant from the liquid pipe, observe the residue discharged from the refrigerant, smell its taste and observe its color. (This article comes from WeChat official account, the encyclopedia of heating and cooling. Tips: After the compressor is burned, it is sour and sometimes pungent.)
After removing the compressor, pour out a little refrigerant oil and judge the situation by its color. Before leaving the main engine, tape the high and low pressure pipes or close the valves.
1.According to the above inspection work, there may be three kinds of compressor failure:
Case 1: The compressor motor is not burned, the current is normal, and only the noise is high. (mechanical problems), the treatment method is as follows:
In this case, the oil is not smelly, but only polluted into powder gray, which sinks in the compression, and the pollution in the system pipe is not obvious. Dismantle the original dryer, use nitrogen as much as possible to blow out the high-pressure pipeline, liquid pipe and parts at the low-pressure end from the high-pressure end, and check whether the blown-out objects are oil, dirt, water or other abnormal or foreign objects.
After replacing with a new compressor, install a new dryer, and add nitrogen pressure to 10KG to detect leakage. If there is no leakage, the remaining nitrogen will be discharged, and vacuum will be pumped from the high and low pressure ends at the same time. The liquid refrigerant is added from the liquid pipe part, and the test can be started only after the amount of refrigerant reaches 70%~80%. (The compressor must be heated for 2 hours)
Case 2: The compressor motor is not burnt out, it can run and the machinery is good, but the current is heavy and overloaded, and it is easy to trip. The treatment method is as follows.
In this case, the oil is slightly burnt and discolored, and the system pipeline is still clean, but in the system where the metal surface has been acidified, the inner wall of the copper tube turns red. After replacing with a new compressor, install a new dryer, and add nitrogen pressure to 10K to detect leakage, so as not to pump vacuum from the high and low pressure ends at the same time.
The liquid refrigerant is added from the liquid pipe part, and the test can be started only after the amount of refrigerant reaches 70%~80%. The compressor must be heated for 2 hours.
Case 3: The compressor motor has been burnt out, so it can't run, and the mechanical quality is unknown. The treatment methods are as follows:
Method 1: The most serious situation is that the oil and refrigerant are smelly, burnt, spicy, and the oil is black as black ink. The tube is full of dirty black film and there will be water. Dismantle the dryer, and short this part as a copper pipe joint or a temporary detachable nozzle. The cleaning agent is pumped into the pipeline system by a chemical pump from a high-pressure pipe to clean and circulate.
Note: The compressor is seriously polluted after burning. If necessary, the cleaning agent should be replaced and cleaned many times.
Method 2: Dismantle the dryer and blow the whole pipeline with high-pressure nitrogen at a pressure of about 10KG. Replace the dryer with a new one, carry out leak detection in the whole system, and pump vacuum at the same time from the high and low pressure ends.
The liquid refrigerant is added from the liquid pipe part, and the test can be started only after the amount of refrigerant reaches 70%~80%. Run for about half an hour after start-up, replace the dryer, and check its dirty condition now. 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 compressor refrigeration oil again, and observe the original new oil situation for the first time.
Note: When replacing the dryer above, air should not enter the system again. In severe cases, the compressor must be removed for oil change, and all the refrigerants should be released for replacement.
Shanghai KUB Refrigeration Equipment Co., Ltd.
| Address : | No. 328 on the 4th plant hengyong Road, Jiading District, Shanghai |
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| Factory Address : | No. 328 on the 4th plant hengyong Road, Jiading District, Shanghai |
| Work Time : | 8:30-17:30(Beijing time) |
| Phone : |
86-021 -63184860-17(Work Time) 86--13916495206(Nonworking time) |
| Fax : | 86-021-53750132 |
| Email : | lucy@shkubao.com |
| Phone : | +86 13588563336 |
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| WhatsApp : | +86 13588563336 |
| Skype : | kub.mick |
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| Email : | kub02@shkubao.com |