Hello,
I will try to keep this as short and concise as possible in hopes someone out there can help me locate our problem.
We have (2) identical Mazak SQT10MS machines. These machines have a spindle/motor and are driven my Mitsu FR-SF drives.
The problems that I am having is on Machine 1.
About a week ago, I was setting up a new job on the machine. I adjusted the jaws for the material and was going to run
the front spindle slowly to verify that the jaws were installed correctly and the material is rotating true. The machine
and control was powered up all day. I went to spin the front spindle manually and received a '39 over amperage' alarm on the
control. A moment later it went to a "16 amplifier not equipt" alarm on the control. (A few weeks prior, I received a
'39 over amperage alarm' and after discussing with Mitsu went through the DC-CT adjustments on Channels 40 and 41 and it seemed to
fix the problem.)
So, I go to the back cabinet of the machine and there are no lights/LED's or anything on the power supply (PW-SF) nor on the FR-SF drive.
This can't be good. So, I power the machine down and back up and still nothing on the power supply or drive.
I immediately contacted a CNC drive repair company and they had me check a few things. They had me pull the middle and lower plugs off from the right back side of the SF-CAA board. I then fired up the machine and we have an amber led on the power supply and lights in the drive. Long story short, it seemed possible that
one or more of the output transistors on the SF-CAA board were bad as well as the possibility of other components. There may
even be some IGBT's shot. They wanted me to pull the front hinge panel off and send it to them for replacement. Roughly $2500.
The problem is that if there were IGBT bad, this fix did not replace those as they are a different part of the drive. So, I didn't do this.
Instead, I found a complete used FR-SF drive with the exact SF-CAA board, part number, etc. So, I bought it and had it shipped to me.
I moved the SF-TL stacked card from my old drive to the new drive, moved all jumpers on the new drive to match exactly what was on the old
drive. I installed the drive and fired it up. It came up fine, with no errors. I adjusted the DC-CT channels 40 and 41 as they were slightly
out of range. There are no alarms when the machine is fired up and idle.
Now, when I go and 'start' the spindle manually (as I was originally trying to do), I am getting a '39 over amperage' alarm on the control
and a 'alarm 32' on the drive. Note that the spindle does not even move a fraction or even attempt to move. It is like there is a dead
short. Nothing moves and I get an immediate alarm when I hit start. Something is pulling this down. The power supply lights and SF-CAA board
lights stay on. Just note the alarm 32.
So, after talking to Mitsu and Mazak, I continued to troubleshoot. I disconnected the motor leads from the lower right of the drive and attempted to run the spindle (spindle actually not turning) and it runs fine for about 30 seconds and then alarms out with 'alarm 23'. According to Mitsu this should be expected because it is not getting the expected feedback. Drive running, but no feedback coming back (spindle not actually turning). So, this proved that the drive
seems to be fine.
Now I am trying to determine of there is a problem with the spindle motor, motor contactors, cables, etc. I disconnected the cables from the drive to the KMSDLT contactor. I also removed the 'U,V,W' and 'Z,X,Y' motor cables from the KMSDELT contactor. I followed these cables back through the machine and all 6 seem to terminate to the motor cables which are located in an enclosure just above the motor (same box as the scale). The cable/motor lead connects are a bolt/nut type of connection that are shrink tubed and tie wrapped inside of this junction box just above the motor. They seem very clean and secure. So, I believe that these connections/cables are good and I have reliable U,V,W and Z,X,Y motor contacts in the electrical cabinet.
Per Mitsu. I tested each of the phases with an ohm meter to ground. All 6 came back at 'OL' which is what I understand they should be. I then tested with an ohm meter between each of the phases U,V,W and Z,X,Y. According to Mitsu. and others I have talked to, I should be expecting a very low ohm reading. Instead, I am getting 'OL' for each of the 6. It is acting like there is an 'open'. This does not make a lot of sense to me. I would expect there would not be an open, but rather a small resistance from the motor windings. Also, the control is signaling an 'over amperage alarm', which seems to me like a grounding problem.
Then after talking to Mitsu and others, they recommend that I get a motor guy in there to to a 'Megger' test on the motor. I had a guy come in this morning
and do a Megger test on each of the phases of the motor. He said it all tested out fine. There were no shorts to ground on any of the phases. We tested the motor cables with the Megger inside the cabinet panel (includes cables) and directly inside of the junction box mounted above the motor. All phases test fine.
So, now I am stuck. I am getting an alarm 32 on the drive and the machine alarms out instantly upon pushing the button.
I am wondering the following:
1. There must be a sensing device on the drive to sense this motor current and it is telling the drive to alarm out. What component is it that is sensing this current and telling it to alarm 32? Could it be set to sensitive or be faulty? A dip switch or jumper that is wrong?
2. Why is the ohm reading between the phases of the motor reading 'OL'? It seems there should be a very low resistance on each of the phases and the resistances should be somewhat similar to each other. Instead all of them are 'open'?
3. Is there another contactor or panel mounted to the motor somewhere that could be causing this 'open' or alarm? The windings seem to be fine based on the Megger testing.
FYI...I also changed out the KMSSTAR(left) motor contactor thinking it might be faulty as it is releasing immediately when the start button is pushed. But, now I think the alarm causes this contactor to drop out.
I have not swapped out the KMSDELT (right) motor contactor yet. Could this be the cause of the problem?
Not sure where else to go with this.
Thank you so much for your time to review this and for any advice you may have.
Regards,
Mike
I will try to keep this as short and concise as possible in hopes someone out there can help me locate our problem.
We have (2) identical Mazak SQT10MS machines. These machines have a spindle/motor and are driven my Mitsu FR-SF drives.
The problems that I am having is on Machine 1.
About a week ago, I was setting up a new job on the machine. I adjusted the jaws for the material and was going to run
the front spindle slowly to verify that the jaws were installed correctly and the material is rotating true. The machine
and control was powered up all day. I went to spin the front spindle manually and received a '39 over amperage' alarm on the
control. A moment later it went to a "16 amplifier not equipt" alarm on the control. (A few weeks prior, I received a
'39 over amperage alarm' and after discussing with Mitsu went through the DC-CT adjustments on Channels 40 and 41 and it seemed to
fix the problem.)
So, I go to the back cabinet of the machine and there are no lights/LED's or anything on the power supply (PW-SF) nor on the FR-SF drive.
This can't be good. So, I power the machine down and back up and still nothing on the power supply or drive.
I immediately contacted a CNC drive repair company and they had me check a few things. They had me pull the middle and lower plugs off from the right back side of the SF-CAA board. I then fired up the machine and we have an amber led on the power supply and lights in the drive. Long story short, it seemed possible that
one or more of the output transistors on the SF-CAA board were bad as well as the possibility of other components. There may
even be some IGBT's shot. They wanted me to pull the front hinge panel off and send it to them for replacement. Roughly $2500.
The problem is that if there were IGBT bad, this fix did not replace those as they are a different part of the drive. So, I didn't do this.
Instead, I found a complete used FR-SF drive with the exact SF-CAA board, part number, etc. So, I bought it and had it shipped to me.
I moved the SF-TL stacked card from my old drive to the new drive, moved all jumpers on the new drive to match exactly what was on the old
drive. I installed the drive and fired it up. It came up fine, with no errors. I adjusted the DC-CT channels 40 and 41 as they were slightly
out of range. There are no alarms when the machine is fired up and idle.
Now, when I go and 'start' the spindle manually (as I was originally trying to do), I am getting a '39 over amperage' alarm on the control
and a 'alarm 32' on the drive. Note that the spindle does not even move a fraction or even attempt to move. It is like there is a dead
short. Nothing moves and I get an immediate alarm when I hit start. Something is pulling this down. The power supply lights and SF-CAA board
lights stay on. Just note the alarm 32.
So, after talking to Mitsu and Mazak, I continued to troubleshoot. I disconnected the motor leads from the lower right of the drive and attempted to run the spindle (spindle actually not turning) and it runs fine for about 30 seconds and then alarms out with 'alarm 23'. According to Mitsu this should be expected because it is not getting the expected feedback. Drive running, but no feedback coming back (spindle not actually turning). So, this proved that the drive
seems to be fine.
Now I am trying to determine of there is a problem with the spindle motor, motor contactors, cables, etc. I disconnected the cables from the drive to the KMSDLT contactor. I also removed the 'U,V,W' and 'Z,X,Y' motor cables from the KMSDELT contactor. I followed these cables back through the machine and all 6 seem to terminate to the motor cables which are located in an enclosure just above the motor (same box as the scale). The cable/motor lead connects are a bolt/nut type of connection that are shrink tubed and tie wrapped inside of this junction box just above the motor. They seem very clean and secure. So, I believe that these connections/cables are good and I have reliable U,V,W and Z,X,Y motor contacts in the electrical cabinet.
Per Mitsu. I tested each of the phases with an ohm meter to ground. All 6 came back at 'OL' which is what I understand they should be. I then tested with an ohm meter between each of the phases U,V,W and Z,X,Y. According to Mitsu. and others I have talked to, I should be expecting a very low ohm reading. Instead, I am getting 'OL' for each of the 6. It is acting like there is an 'open'. This does not make a lot of sense to me. I would expect there would not be an open, but rather a small resistance from the motor windings. Also, the control is signaling an 'over amperage alarm', which seems to me like a grounding problem.
Then after talking to Mitsu and others, they recommend that I get a motor guy in there to to a 'Megger' test on the motor. I had a guy come in this morning
and do a Megger test on each of the phases of the motor. He said it all tested out fine. There were no shorts to ground on any of the phases. We tested the motor cables with the Megger inside the cabinet panel (includes cables) and directly inside of the junction box mounted above the motor. All phases test fine.
So, now I am stuck. I am getting an alarm 32 on the drive and the machine alarms out instantly upon pushing the button.
I am wondering the following:
1. There must be a sensing device on the drive to sense this motor current and it is telling the drive to alarm out. What component is it that is sensing this current and telling it to alarm 32? Could it be set to sensitive or be faulty? A dip switch or jumper that is wrong?
2. Why is the ohm reading between the phases of the motor reading 'OL'? It seems there should be a very low resistance on each of the phases and the resistances should be somewhat similar to each other. Instead all of them are 'open'?
3. Is there another contactor or panel mounted to the motor somewhere that could be causing this 'open' or alarm? The windings seem to be fine based on the Megger testing.
FYI...I also changed out the KMSSTAR(left) motor contactor thinking it might be faulty as it is releasing immediately when the start button is pushed. But, now I think the alarm causes this contactor to drop out.
I have not swapped out the KMSDELT (right) motor contactor yet. Could this be the cause of the problem?
Not sure where else to go with this.
Thank you so much for your time to review this and for any advice you may have.
Regards,
Mike