VAC II spindle drive fix notes
as these drives are getting older, are expensive as all get out to repair or replace, thought I'd start a 'notes' thread on issues weve ran across so far...
just had one with a '1052 VAC input voltage drop' and 14 alarm on the PCB.
problem was the little tiny Fuji relay in the bottom right corner of the drive had a flaky contact, not energizing the main contactor. lock it out, let it discharge for a while, and you can push the little relay actuator thru the bottom-right side carry handle hole, get a meter in thru the front, got from 10-500 ohms on the center contact(wire 112 feeds the main contactor). my Buddy suggested simply pulling the right side off the drive for access, made it super easy to pull the relay without having to pull all the bussing out from the front.
twice now weve had them with '16' alarms at boot up, and VAC start failed on the CRT...sometimes cycling the power would clear it...found the 5volt fuse holder beneath the supply was flaky, 5v checked good but was dipping on inrush/bootup- by dumb luck I bumped the fuse and saw flicker...simply cleaned the forks in the fuse holder and scraped the sides of the fuse a little with a exacto blade, problem fixed.
anyone else with any simple/stupid fixes on this stuff, PLEASE share...I *heard* Okuma wanted 28k for this friggin drive/refuses to supply schematics, and now no longer supports it wants you to update to a newer model...$28,000 for a $2 fuse clip or a $25 relay??? not unless absolutely necessary. these seem to be very very good drives, but they are getting old, suffering from simple failures- at least simple if the OEM would provide adequate drawings... in my opinion if okuma were more open, they would have a lot more fans out there- I'm not one, we need machines to make money, not cost money over 'secret schematics'. I hear Fanuc is getting to be the same way anymore though...
Re: VAC II spindle drive fix notes
I have a 1994 LNC8 with a Vac III (D6) drive. Im getting an alarm 15 on the drive and the M1 and M2 lights are flashing, CPU light is lit , and lights 3&12 are lit green.
On the control Im getting a 78 alarm-P Vac start spindle 1 1001FFFF.
Gosiger said their manuals explanation is "open phase".
.
I have checked the simple fuses and the breaker for the drive and they are all good.
Any suggestions would be appreciated
Thank!
Re: VAC II spindle drive fix notes
that same manual is posted above in post#14.....
it means one of the 3 phases is not connected so you have a high voltage fault on the lower board of your spindle drive unit.
you could test the IGBTs and maybe one of them is bad. read my how to test notes in post#14.
changing the IGBTs does not guarantee a fix.
if the IGBT blew because of something else then you need to find that something else.
most of the origins of IGBT failure come from the top board. usually that's the most difficult part because the top board is complicated.
basically you are screwed and you'll have to buy a new/refurbished VAC III drive from Okuma or some other 3rd party repairer.