AL-03 Alarm on AC Drive

[TR MFG]

I’m working on a Fanuc Spindle Drive, Model # A06B-6059-H003, in an early 90’s Kiwa 510 Machining Center. You can command the spindle in either direction, but when you give it a stop command it just coasts to a stop. If it coasts long enough it will display an AL-03 alarm on the drive. I don’t have a manual for the drive, but from what I’ve found on the web AL-03 is “DC Link fuse blown” That made me believe that the IGBT’s were probably smoked and I would need to check the firing circuit of the top board, but we just so happen to have a spare drive on hand in the shop, so I swapped over the whole unit. Now, I don’t know anything about the drive I put in (whether its good or bad) it was just on the shelf and labeled good, which doesn’t mean much, but after swapping it in , it operates exactly the same……stop the spindle and coast….eventually giving the AL-03 alarm….

So, do I have 2 bad spindle drives?

I’ve checked all my voltages, fuses, megged my spindle motor(phase to ground) and everything seems to check ok.

I think I’m just a little thrown off because the two drives operate exactly the same.

Anybody have anything else they can think of that I can check before I send these drives off to be serviced?


Thanks…..Matt

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[Al_The_Man]

AL-03 shows F7 or F4 fuse blown, depending on the model.
I assume this is a regeneration circuit fuse, and shows when the spindle is being braked.
It also points to solid state power device?
Al.

[TR MFG]

Thanks Al, where would I find this F4 or F7 fuses, there are 5 or 6 fuses on the drive, which all check good, and none of them are labeled F4 or F7.

And by solid state power device are you refering to the power unit attached to the mother board...


I believe your correct that it is a regeneration circuit, when it trys to brake, it slams the load meter to %150...

[cnc2149]

The smaller "S" Series Spindle drives (A06B-6059-H001 ... H003) use a separately mounted discharge resistor instead of AC power line regeneration. Remove the 2 large wires at T2 (upper RH corner of amp) and ohm check the cables + resistor (not the drive). I think that dump resistor should read 16 ohms). I'm guessing it may be open.

[gbowne1]

I had this same problem when I installed my 6059 drive. Keep in mind I have a 6S installed now, but I have had others on my VMC for testing. Any one got tips on setting up the "S" Spindle Servos???

[TR MFG]

The smaller "S" Series Spindle drives (A06B-6059-H001 ... H003) use a separately mounted discharge resistor instead of AC power line regeneration. Remove the 2 large wires at T2 (upper RH corner of amp) and ohm check the cables + resistor (not the drive). I think that dump resistor should read 16 ohms). I'm guessing it may be open.

Thanks CNC2149, I ohmed the resistors at the discharge unit, and they checked good(15.9ohms)….ohmd the wires at the drive and I’m getting anywhere from 30-50…..so I think I’m going to trace these wire through the machine and see if I have a bad connection somewhere.. Thanks for your help, Matt

[gugu]

In my case, the 2 resistors R51 and R52 on the DC buss were open.
Replace the 2 resistors.