[landslide1]

Does anyone have any experience with Fanuc drive errors? I was getting a high current alarm Al-12 and sent the drive in for repair, now the drive is giving AL20 high current on one phase - checked on startup. The dive has a not ready signal so the control is booting with an alarm state an estop signal.
Even with the motor disconnected the drive reports an AL-20 which makes me think it is the drive and not the install. I have checked the phase voltages and have 208V between phases at the drive.
Can AL-20 be caused by incorrect phase connection order?
have I been duped by the repairer? This error should have been evident when they tested the drive and powered it up. They claimed they power it up but couldn't machine test as there are too many control inputs to simulate.

[zavateandu]

AL 19 and 20 is related to tranzistors so i would checked them forst and change if are not good

[landslide1]

The drive was just repaired and they claimed to have check the transistors.

Do you mean the transistors on the drive board or the transistors/igbt modules underneath?

[servtech]

Does anyone have any experience with Fanuc drive errors? I was getting a high current alarm Al-12 and sent the drive in for repair, now the drive is giving AL20 high current on one phase - checked on startup. The dive has a not ready signal so the control is booting with an alarm state an estop signal.
Even with the motor disconnected the drive reports an AL-20 which makes me think it is the drive and not the install. I have checked the phase voltages and have 208V between phases at the drive.
Can AL-20 be caused by incorrect phase connection order?
have I been duped by the repairer? This error should have been evident when they tested the drive and powered it up. They claimed they power it up but couldn't machine test as there are too many control inputs to simulate.

Static tests are not always proof the drive is good, without a test rig there is always the chance they missed something.

Yes, make sure phases are correct connection in clockwise rotation. Also any other position where the 3 incoming phases are used. I had a drive where incoming phases were correct but crossed internally causing a drive fault on power up.

Try and use a fanuc repair specialist who can properly test any repairs they make.

[landslide1]

"Yes, make sure phases are correct connection in clockwise rotation. Also any other position where the 3 incoming phases are used. I had a drive where incoming phases were correct but crossed internally causing a drive fault on power up."

Is there a procedure for this? or should I just try swapping the phases? I don't think there are any internal crosses as the machine was working before I removed the drive I tried to use a reputable repairer and the shop was one who a respected CNC tech used. Unfortunately good techs are rare in Australia.

[landslide1]

further testing and the problem is intermittent so I don't think it is the phase supply. One of the remedies for AL20 is to check the control boards connections and a clean has the drive booting sometimes without error. other times it still has the al-20. maybe a dry joint somewhere.

Now I’m getting just a okuma control error 108A which is related to the estop.

[servtech]

further testing and the problem is intermittent so I don't think it is the phase supply. One of the remedies for AL20 is to check the control boards connections and a clean has the drive booting sometimes without error. other times it still has the al-20. maybe a dry joint somewhere.

Now I’m getting just a okuma control error 108A which is related to the estop.

Was the machine working ok before the drive repair? ie. Were any of the current issues there before?
If no, suspect the drive.

E-stop is a daisy chain signal through many items on the machine, if any contact in that chain is open you will get the alarm. Drive ready/ok is probably one of them.

[landslide1]

Was the machine working ok before the drive repair? ie. Were any of the current issues there before?
If no, suspect the drive.

E-stop is a daisy chain signal through many items on the machine, if any contact in that chain is open you will get the alarm. Drive ready/ok is probably one of them.

the machine was working well until I got the AL-12 high current alarm on the spindle. Blown igbt/transistor module on the lower board. it was then sent in for repair. Now an al-20 which is intermittent.

my thinking is that the AL-20 is more likely a bad connection in either the top to bottom drive boards as I have it reliably booting without errors if the strain is removed from the top and bottom board connections. The drive is going back to the repairer to check the connections in the board.

the alarm may be from something different than the drive. A cnc tech suggested bypassing the estop to see if that clears the alarm. if so then there is a break in the estop. then to track it down. the estop maybe from a hard limit and not the drive.
I have a spindle position sensor to give the repair shop to help test the drive but I don't have the spindle temp sensor. would you know the resistance needed to fool the board into thinking the temp is normal?