FANUC drive 8,9,A alarm how to troubleshoot

For more details, please check EASYCNC YouTube video here.

FANUC drive 8,9,A alarm how to troubleshoot?

FANUC servo drives are 8, 9, A and 8 in addition to the fan alarms that are most likely to occur.  9. A. Alarm, how to troubleshoot such an alarm?

1 Check the motor power line and motor resistance to ground, which can be detected from the motor end

It can also be detected from the drive side

Servo motor power line:

A---U (drive side) B---V (drive side)

C---W (drive side) D---G (ground side)

The resistance between UVW is generally about a few ohms, and the resistance value between them is almost equal. UVW resistance to G (ground) should be more than 100M ohms, the greater the resistance, the better the insulation.

Motor coil diagnostics:

Measured with a megohmmeter 500V

Good: >100MΩ

Start aging: 10~100MΩ

Severe aging: 1~10MΩ

Faulty: less than 1MΩ

Measuring from the driver end can eliminate whether the cable and power cable plug are short circuited or broken. 2 Exchange servo drive, or without servo drive, you can exchange bed XY axis (Lijia), generally XY motor is the same. Exchange the power line and feedback line directly from the drive end. This allows complete detection of cable and motor problems. The power line plug has a foolproof function, and you need to use a needle ejector (refer to the article: What should I do if the FANUC power line cannot be exchanged?). ）

3 Look at the running load of the machine tool, if the load is too large, repair the machinery. (1) Set the display operation monitoring screen parameter OPM (N0.3111#5) to 1. (2) Press the function key "[POS]" to display the location screen. (3) Press the Continue Menu key → display the softkey [Monitor]. (4) Press the soft key [Monitor] to display the following screen. 

Summary: When 8, 9, A, alarm, after eliminating the large load caused by the mechanical card owner, check the motor, power line and drive, and the exchange method diagnosis speed is the fastest.