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Posting an accurate wording of the alarm is a good place to start.
"Something" in the wording will keep most people away.
Hi,
I have a QT28 with T2 control. It will run the spindle at 1000rpm all day long but if we go much faster the spindle drive will fault out giving an ALO 32 alarm (over voltage is what Mits told me on the phone but when I looked it up I found over current instead). It is a FR-SF drive. Any thoughts on what the issue is?
Thanks
Try running the spindle at 10 RPM.
Does it turn smoothly, or pause (may even turn backward) then jump a little?
You may need to look at the motor pulley to see that the jump happens at the same place in the motor rotation.
If jumpy, the power supply at the top of the FR-SF that has a bunch of voltages that it provides.
There is probably 1 or more that are low or missing.
Then there will be sections of the 3 phase power to the motor that are missing.
As the speed increases, the current draw on the phase after the missing section will tend to have an overload, if severe enough, the overload can take out the associated power transistor module.
Bill
Check the 3 phase power to the bottom of the FR-SF. Phase to phase and phase to ground, 6 checks.
Line voltage may be a little high.
When does it fault out above 1000 RPM?
Picking up speed? slowing down? or as soon as it arrives at speed? Or while cutting.
Are you using constant RPM or Constant surface speed?
Alright, so I am finally getting back around to this issue, we have only needed to use the lathe intermittingly and just used it at the slower rpm without issue. Well this morning the machine would not come up ready because the drive now has a ALO 24 alarm (breaker trip). I have gone thru Mitsubishi Alarm 24 troubleshooting (USA-E99991-042-*), it does not appear to be the motor or sf-ca card.
I have also gone thru the first part of the FR-SF Checking transistor module document. It notes that a analog multimeter should be used, (using my digital one switching positive and negative leads did not change the measurements like the document showed, so I bought an analog one). I do now get different readings switching the leads but am not sure if I am checking/understanding it correctly. Currently it is looking to me like all of the transistors on the right side of the drive are reading bad. Does it seem likely that all would go bad at the same time?
Thanks
Note I previously tried to change the accel and decal drive parameters, since this is a T2 they aren't supposed to be saved in the control, but when I tried to change them on the drive itself they appear to be hidden (like they are bus linked). Talking with Mits and Mazak got me nowhere on this as it appears that an FR-SF paired with a T2 is not very common.
View attachment 277523
Well I am either doing something wrong or this Mits document is wrong. I got replacement transistors and according to the Mits document they are all bad as well. Once I found this I went and checked a running machine and all of those transistors "check as bad" as well.
Replace all capacitors in both the power supply and the drive.
Also wondering if anyone would know how to get parameters #33, #5E, and #5F to show up on the drive, when I toggle thru the parameters they restart back to the beginning before getting to these.
Did you ever get to the proper manual? BNP-A 0801-19-D-E
Seems that there are many parameter screens see pg 30 of above doc.
Bill
The file I have is over 15 Meg. I can't PM a file that size.
PM me your email address and I will try that way.
Bill
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