Combined with the field experience, I will give you the high incidence of causes according to the practical priority ranking, convenient for you to rank:
* Fanuc servo motor short circuit
The winding insulation is aging or damp, the resistance drops, and the current spikes abnormally high.
* Fanuc servo cable damage
Outer skin cracked, insulation layer damage, light is occasional alarm, heavy is the boot second report.
* Fanuc servo amplifier failure
IGBT/IPM module burned out, drive board moisture, solder joints welding.
* Unstable supply voltage
Grid fluctuation, transformer failure, filter capacitor aging.
* Mechanical overload
The silk rod is stuck, the guide rail resistance is big, the bearing is holding dead.
* Servo gain/current limit setting error
Gain is too high, the current limit value is set indiscriminately, resulting in false trigger protection.
Maintenance Master's Troubleshooting Steps
My own habits, is first "external fast row”, then "internal deep row”.
-1. Power off and wait. Turn off the main power and wait for more than 5 minutes to let the capacitor discharge completely. By the way, feel the temperature of the drive radiator, sometimes you can feel the traces of overheating.
-2. Look at the appearance. Motor, cable and drive to see if there are any burn marks, oil, or cracks.
-3. Measure the motor winding. Use a multimeter to measure the resistance of the three-phase winding, once the difference is large or close to the short-circuit value, the motor is basically declared "retirement”.
-4. Replace the wire test run. Spare line, directly change a cable to rule out the problem.
-5.
Drive swap method. Have the same type of spare drive, change on the test machine, immediately be able to determine whether the drive body is bad or external reasons.
-6. Look at the parameters. Fanuc parameter page, check the current limit and servo gain, unreasonable directly restore the factory values.
Suggestions to Prevent the Problem from Occurring
* Do not replace motor and encoder wires until they are "out of gas”, but check them once every three to five years.
* Add dehumidifier or desiccant to the cabinet during rainy season or high humidity.
* Look at the load curve before large cutting, do not just increase the feed and depth of cut.
* Regularly blowing dust to clean the heat dissipation channel of the drive to prevent overheating.
