What should I do if the compressor burns out？
Why does the compressor burn the motor? What is the cause of the burn-in phenomenon? A summary of the reasons for motor burn-in can be divided into: load, power supply, motor insulation, and lack of equivalence.
One, common causes of compressor motor burnout
1, lack of phase
Reason: Generally, it is caused by lack of phase of the power supply (one phase is not supplied or the supply voltage is insufficient) or the contact point of the contactor in the line is not closed, the wire connection point is disconnected, loose or the contact position is oxidized.
Characteristics: one or two phases (level 4) in the winding are all blackened, the coil is damaged and symmetrical, and there are rules for phase loss.
2, overload
Reason: Generally, the motor runs for a long time with overcurrent, overheating, frequent starting or braking, and wiring errors (delta connection to star connection).
Characteristics: all windings turn black, and the end straps change color and become brittle or even break.
3, turn-to-turn
Reason: The enameled wire breakage caused by the motor manufacturing process, and the water, acid, and other corrosive substances in the system can also cause such failures.
Characteristics: The windings are partially burnt, usually when the inner cavity of the motor is clean, there is only one explosion point.
4. Alternate
Reason: The interphase paper is not put in place, or the interphase paper (casing) is damaged.
Feature: Burn out between two adjacent phases of the motor.
5. Ground strike
Reason: The distance between the coil and the end cover base is not enough.
Feature: There are burnt marks in both places between the coil and the end cap or the end cap.
2. Treatment method after the compressor burns out
(1) If the compressor has been burned or mechanically failed, or worn out, which will cause the inevitable pollution of the refrigerant system, the situation is as follows (the system is smelly in the following situations, and you can know it at first smell):
1. The residual refrigerating oil has been carbonized, contains acid, and is dirty in the pipe.
2. After the compressor is removed, the original system pipe must be corroded with the air, causing condensation effect, increasing the residual moisture, and corroding the copper pipe and the parts on the pipeline, causing a dirty film, which will affect the operation after the compressor is replaced next time. Features.
3. Part of the worn copper, steel, alloy dirt powder must have flowed into the pipeline to block some of the thin pipe holes.
(2) The results after replacing the system without processing the compressor directly with a new compressor are as follows:
1. It is impossible to vacuum completely, and the vacuum pump is easily damaged. After adding the new refrigerant, the refrigerant only plays the function of cleaning the system parts, and the pollution of the whole system still exists.
2. The new compressor and refrigerating oil, the refrigerant will be all contaminated within 0.5-1 hour immediately. After the refrigerating oil is not pure, the original lubricating properties will be destroyed. Metal dust entering the compressor may penetrate the motor insulation film and short-circuit, and then burn out, causing increased friction between the shaft and the shaft sleeve or other operating parts, and mechanical seizure.
3. The mixture of refrigerant, oil, original pollutants, and acidic substances will cause more acidic substances and water to increase. The copper plating phenomenon will begin to increase, the mechanical gap will be reduced, and friction will increase.
4. If the original dryer is not replaced, it will release the original water-absorbing and acidic substances. Acidic substances will slowly corrode the skin insulation film of the motor enameled wire.
Under the above conditions, the new compressor will be completely burned out in about 1 month! !
Processing process:
(1) How to deal with a host refrigerant system whose compressor has burned out or failed? The compressor is damaged, of course it needs to be replaced, and it is very urgent, but before taking action to prepare materials and tools, the following points must be done:
1. Whether the contactor, overloader, and temperature control in the control box have any quality problems, they must be checked and confirmed until there is no problem.
2. Whether various set values have been changed, analyze whether the compressor is burnt due to the change of set values or wrong adjustment.
3. Check the abnormal condition on the refrigerant pipeline and correct it. Make sure the compressor is burned or stuck, or half burned.
4. Use a shaker to measure the insulation and a three-meter to measure the coil resistance. Talk to the relevant personnel of the customer to understand the general situation of the cause and effect, as a reference for judgment.
5. Try to vent the refrigerant from the liquid pipe, observe the residue discharged from the refrigerant, smell its taste and watch its color. (This article comes from the public number of Encyclopedia of Cold and Warm. Warm reminder: After the compressor is burned, it will have a sour and pungent smell.)
6. After removing the compressor, pour out a little frozen oil and judge the situation by watching the color. Before leaving the host, wrap the high and low pressure pipes with tape, or close the valve.
(2) According to the above inspection work, there may be three compressor failure conditions:
Situation 1: The compressor motor is not burned out, the current is normal, only the noise is loud. (Mechanical aspects), the solution is as follows:
In this case, the oil is not odorous, only polluted into a powdery gray form, sinking inside the compression, and the pollution in the system tube is not obvious. Remove the original dryer and use nitrogen as much as possible to blow off the high-pressure pipe from the high-pressure end, as well as the liquid pipes and the low-pressure end parts in sections, and check whether the blown out is oil, dirt, or Moisture or other abnormal shapes or foreign objects.
After replacing with a new compressor, install a new dryer, and add nitrogen pressure to 10KG for leak detection. When there is no leakage, the remaining nitrogen will be discharged, and the high and low pressure ends will be simultaneously vacuumed. Add liquid refrigerant from the liquid pipe to 70%~80% of the amount of refrigerant before starting the test. (The compressor must be heated for 2 hours)
Situation 2: The compressor motor is not burned out, it can be operated, and the machinery is in good condition, but the current is large and overloaded, and it is easy to trip. The treatment methods are as follows.
In this case, the oil has a slightly burnt smell and discoloration, and the system pipeline is still clean, but the metal surface has been acidified in the system, and the inner wall of the copper pipe turns red. After replacing the new compressor, install a new dryer, and add nitrogen pressure to 10K for leak detection, and vacuum at the high and low pressure ends at the same time without leakage.
Add liquid refrigerant from the liquid pipe to 70%~80% of the amount of refrigerant before starting the test. The compressor must be heated for 2 hours.
This situation must be noted. It is possible that the original power supply stability and possible load of the equipment are too large, or the result of stopping the control too frequently. Refrigeration Encyclopedia suggests to solve these problems. The danger always exists, or it cannot be completely solved.
Situation 3: The compressor motor has been burned out and cannot run, and the machinery is not well known. The treatment method is as follows:
Method 1: The most serious cases of this situation are oil and refrigerant smelly, burnt, spicy, oil black as black ink, and the inside of the tube is full of dirty black film and moisture. Remove the dryer, and short-connect this part as a copper pipe joint or a temporary detachable pipe joint. A chemical pump is used to pump the cleaning agent into the piping system through the high-pressure pipe for cleaning circulation.
Note: The serious pollution situation after the compressor burns, the cleaning agent must be replaced if necessary, and the cleaning agent must be cleaned multiple times.
Method 2: Remove the dryer and blow through the entire pipeline with high-pressure nitrogen at a pressure of about 10KG. Replace with a new dryer, leak detection in the whole system, and vacuum simultaneously from the high and low pressure ends.
Add liquid refrigerant from the liquid pipe to 70%~80% of the amount of refrigerant before starting the test. Run for about half an hour after starting, replace the dryer, and observe its turbidity, the second time the new dryer must run for another 3 hours, observe the result, and replace it if necessary until the system is completely clean. Finally, change the compressor refrigeration oil and observe the original new oil condition for the first time.
Note: When replacing the dryer above, do not enter the system again. In severe cases, the compressor must be removed for oil replacement, and all refrigerants must be released and replaced.
