Reasons for ring burnout in the motor of an oil-injected screw compressor
Thread Content
This post was last edited by TF123 on 2012-4-12 at 21:43. I have an American Sulzer-type oil-injected screw air compressor with a water-cooled motor (380 volts), and the motor’s windings have burned out. The following are some of the symptoms that have occurred; please discuss what may have caused the motor to be damaged Some of the symptoms that have occurred: 1. It stops automatically a few minutes after starting up, with an indication of overload on the main unit; manual rotation of the shaft shows no signs of jamming. After the electrician tightened the wires related to the relay, it was able to operate for a while ； 2. After running for a period of time (about 1 hour per run), an alarm indicates that the oil filter is clogged; however, the pressure difference required for automatic shutdown has not been reached, so the machine is stopped manually ； 3. There is no significant vibration or abnormal noise during operation, but the operating current exceeds the rated current by 20A ； 4. The oil filter could operate for a few more hours after being cleaned (as the spare parts had not arrived); once the spare parts arrived, the oil, oil filters were replaced. The oil filter became clogged three times, and three new oil filters were used. After running for 5 hours the last time, the motor was damaged.
I’m not very familiar with screw compressors, but since the crank rotation works fine, mechanical issues can probably be ruled out. Check the process to see if the outlet pressure is set too high or the flow rate is too large, resulting in motor overload. As for the high pressure difference in the oil filter, it doesn’t seem to be closely related to this
Upon investigation, it may be as follows: During operation, the screw air compressor experiences overload. Check whether the electrical components are functioning properly; if so, verify whether the two-phase voltage is too low, whether the three-phase voltage is stable, and whether there are any issues with the contacts of the contactors. Any of these problems requires adjustment or replacement. If the electrical components are not functioning properly, it is necessary to check whether the screw air compressor starts under load; for example, if there is no air release, verify that the venting pipeline is in good condition ； Is the unloading valve malfunctioning? If so, it needs to be replaced ； Check whether the discharge pipe is connected incorrectly; if so, it needs to be reconnected. Abnormal operation of electrical appliances can also be attributed to a malfunction in the motor; poor insulation might be the cause, in which case repair is necessary ； It might be that the lubrication isn’t good enough; in that case, add more lubricant ； The worst case is that the motor burns out, in which case it needs to be repaired or replaced. If the motor of a screw air compressor operates normally but the main motor is overloaded or stalls, another possible cause is the failure of the lubricating oil, which leads to damage to the bearings and requires their replacement. If the host machine becomes overloaded or stalls due to a fault in the head unit, the head unit needs to be repaired. An answer with no answer!
If the temperature is too high, check whether the oil cooler is clogged with scale
This post was last edited by 276495457 on 2012-4-10 21:23. Check the compressor bearings; they may be damaged, and abnormal axial forces can cause the motor to become overloaded as well as lead to clogging of the filter
It seems that there is a problem with the quality of the motor itself; with higher-quality motors, such situations occur very rarely
Seemingly, there might be an issue with the assembly; shaft misalignment occurs after it starts operating； Or perhaps the bearing has slipped, but this was not detected and the machine continued to operate, leading to the aforementioned consequences; it is unknown whether the internal damage to the machine is severe. The compressor should now be disassembled for inspection and repair; could you share more about the actual cause?