SINUMERIK-3 CNC system alarm solution

Swiss S-45 CNC grinder, SINUMERIK-3 CNC system, alarms 123, 122 and 222 appear irregularly when working. The alarm sometimes appears when the Z axis moves fast or just starts moving, and sometimes it appears when the grinding wheel is corrected.
Analysis and repair process:

The situation of this fault is more special. After inquiring to the operator, it is normal when the machine is turned on every morning, but the fault occurs frequently when working until the afternoon, and the machine tool cannot be used. Check that the motor and the servo controller are normal, and check the alarm to indicate that the cause is excessive mechanical resistance. Manually check the screw and motor without abnormality, but when removing the machine tool protective cover and inspecting the screw, accidentally found both sides of the protective cover A large amount of abrasive debris has accumulated. It turned out that the machine tool had stopped overnight, and the abrasive debris had dried. It usually works normally when it is turned on in the morning. However, after being used for a period of time, the accumulated abrasive debris expands due to the coolant, which causes the resistance of the protective cover to move. After removing the abrasive debris, the fault is eliminated. After normal use for a long time, the above alarm appeared again. After checking the fault, it was found that there are many reasons, such as motor failure, grating scale failure, mechanical failure, etc., and the most common reason is that the grating scale is contaminated by compressed air with water vapor. Compressed air is passed through the grating ruler to prevent dust from entering people, but due to the high humidity in wet weather, the water in the compressed air is not filtered and blown at the same time, which makes the grating ruler fuzzy and causes detection errors. Therefore, it should be analyzed according to the specific situation during the inspection, and it is impossible to generalize the same faults that occur.