FANUC CNC 414 alarm

#6 LV low voltage alarm → LED [2] or [3] lights up    
#5 OVC overcurrent alarm          
#4 HCA Abnormal current alarm → LED [8] lights up      
#3 HVA overvoltage alarm → LED 【1】 lighted       
#2 DCA discharge alarm → LED [4] or [5] lights up    
#1 FBA disconnection alarm          
#0 OFA overflow alarm          
When the above is normal, #0 to #7 are all 0.          
It is concluded that servo current abnormality is usually caused by bad or damaged IPM and degraded insulation of motor or power line.         
Open the electrical cabinet, found that the servo amplifier LED display [8.], check the maintenance manual, the servo amplifier LED display [8.] the meaning of the following:         
(1) Content inverter IPM alarm          
(2) Main causes and troubleshooting methods          
(a) Please press the panel (control substrate) effectively.         
(b) Remove the motor power cable from the SVM and release the emergency stop.          
① When no IPM alarm occurs → (b)          
(b) Remove the motor power cord from the SVM and release the emergency stop.          
(c) Remove the motor power cord from the SVM and check the insulation of one of the motor power cords U, V, and W against PE.          
(c) Remove the motor power cord from the SVM and check the insulation of one of the motor power cords U, V, and W from PE.          
If the insulation is normal, replace the SVM.          
(d) Separate the motor from the power cord and check whether the insulation of the motor or the power cord has deteriorated.          
If the insulation of the motor deteriorates, replace the motor.          
If the insulation of the power cord is deteriorated, replace the power cord.          
According to the judgment and reference instructions, start with the simple, check the insulation, the results of the motor three-phase ground about 2KΩ resistance, normal should be greater than 5MΩ resistance, the motor power line U, V, W from the servo amplifier to remove, and then measured again, the situation remains the same.         
Judgment is the motor or power line insulation is not good, remove the X-axis servo motor shield, revealing the motor plug, you see a section of the power line by the oil corrosion bubbles melted, it is estimated that the problem is here, unplug the power line, measure the power line, U, W on the ground about 2KΩ resistance, and then measure the motor, the insulation is good.         
Re-insulate the power line to do insulation treatment, power on all normal.         
When copying the machine and the occurrence of the knife bank 2030 alarm, meaning that the switch is damaged or disconnected.         
After powering down, I checked the front and rear in place travel switches, count sensors, and cables of the tool magazine, and they were all good. Power up and good again, the machine again back and forth for a few minutes of empty running, and then the same alarm, it is too strange.         
According to the site operator said, 2030 alarms often appear, sometimes on their own, and the manufacturer's people have come to the whole, did not find the cause, and successively found a few people to see, or did not find the problem.         
Had to enter the ladder diagram page, from the alarm lamp output backwards to check, after a lot of R internal relay links, and finally found a R internal relay is activated, the R relay output, is controlled by a few input switch signals (due to the drawings are labeled in English instructions, the head of my head are big, it is not easy to find the address of the switch), which has a cutter bank before and after the in place of the travel switches, due to some people! In the machine guard above the station someone (previously check the switch, remove the guard did not come down), causing the machine tool vibration, found that the tool magazine forward in place switch has an abnormality, showing that the switch also has a jitter signal, then the alarm is automatically eliminated, and I told the person above to shoot the switch, and then the alarm occurs, indicating that the switch is bad.         
Previously measured above the switch, because it is manually pressed switch cam, switch on and off very normal, due to switch use for many years, internal reed fatigue, when subjected to vibration contacts are very easy to run, the fault is due to the switch caused by bad, and finally replaced a switch, try the machine for 1 hour, and then did not produce a fault.