Need Help!- Overvoltage / spindle Inop.

[JoBwan]

Ok Guys, I need some insight. I came in last Thursday to my 1998 VF-10 with a 20/30 HP Vector drive running. Serial # 16018. Cycle stopped & wouldn't orient to tool change. Hit MDI...S100...M3...Start. The load meter went to the max and the spindle will not turn. I can turn the spindle by hand. Had no power coming from the vector drive output to the spindle motor. I replaced the vector drive, and now I have power to the motor. But still have the load meter max'ed out and the spindle will only move at 30 RPM. I did check the spindle encoder belt and pulleys...seem to be OK. I've had this machine since 2001 and I have verified the taps are correct for in-coming power. I have 224 VAC to the vector input pins # 4,5,6. I have 8.5 Ohms from the regen unit and open lead from both regen wires to ground. I have 313 to 315 VDC to the servo amps from pins 2 & 3 of the vector drive. I need to get running asap. Welcoming / begging for any input. Thanks in advance.

[Wizzard of H]

Where did you get the replacement vector drive?
New from Haas - else maybe it is also bad.
Besides that, swapping just two motor leads could give a symptom like this.
Double check the wiring if the drive was the only thing changed.

[JoBwan]

????????
Wizzard,
Thanks for the reply. I did buy this directly from Haas. As far as the wiring, I'm a little baffled. I have the same symptoms as the first drive, and no wiring was changed on this machine. I am leaning towards a bad spindle encoder, which may have taken out the vector drive. Not certain tho!! I have been in touch with tech. support in Oxnard and they tell me to just get a tech. in. Money is too tight right now! If I don't get any other ideas, I will need to bite the bullet, I guess.

[Wizzard of H]

Okay.
Here's some more things you can check.

When the servos are on but spindle is stopped, the RPM display on the screen is "live". That is, it shows exactly what the spindle and encoder are doing. If you turn the spindle by hand, that display should show a non-zero RPM. If not, or there are any spindle encoder alarms, you have an encoder problem. Did a belt break?

If the drive is actually getting the motor to turn even slowly, you are probably connected to it. If not, you may have WYE/DELTA switch contactors that are not working and thus causing problem with power to the motor. Even one open contact on those could cause what you are seeing.

Other than that, parameter errors could do this. Has anybody "messed" with parameters?

[Wizzard of H]

What is the reference to overvoltage?
If you are getting that alarm, something else is wrong.

[JoBwan]

Hey Wizzard,
I was able to check the contactors for the "Delta-Wye" and I did find an open lead on one of them. Must be a burnt contact. I am ordering a contactor and crossing my legs that it fixes the problem. Thanks for your input. I will update when this is repaired.

[JoBwan]

Originally Posted by Wizzard of H Okay. Here's some more things you can check. When the servos are on but spindle is stopped, the RPM display on the screen is "live". That is, it shows exactly what the spindle and encoder are doing. If you turn the spindle by hand, that display should show a non-zero RPM. If not, or there are any spindle encoder alarms, you have an encoder problem. Did a belt break? If the drive is actually getting the motor to turn even slowly, you are probably connected to it. If not, you may have WYE/DELTA switch contactors that are not working and thus causing problem with power to the motor. Even one open contact on those could cause what you are seeing. Other than that, parameter errors could do this. Has anybody "messed" with parameters?

Hey Wizzard,
I replaced the contactor and the problem still exists??? If I turn the spindle by hand, the encoder is working properly. (Had Haas tech. support confirm that for me). Not sure what to look for next. No one has admitted to messing with the parameters. Like I stated earlier, it ran until it stopped....

[JoBwan]

Originally Posted by Wizzard of H
Okay.
Here's some more things you can check.

When the servos are on but spindle is stopped, the RPM display on the screen is "live". That is, it shows exactly what the spindle and encoder are doing. If you turn the spindle by hand, that display should show a non-zero RPM. If not, or there are any spindle encoder alarms, you have an encoder problem. Did a belt break?

If the drive is actually getting the motor to turn even slowly, you are probably connected to it. If not, you may have WYE/DELTA switch contactors that are not working and thus causing problem with power to the motor. Even one open contact on those could cause what you are seeing.

Other than that, parameter errors could do this. Has anybody "messed" with parameters?

Hey Wizzard,
I replaced the contactor and the problem still exists??? If I turn the spindle by hand, the encoder is working properly. (Had Haas tech. support confirm that for me). Not sure what to look for next. No one has admitted to messing with the parameters. Like I stated earlier, it ran until it stopped....
__________________
Just a good ol' boy, never meanin' no harm.
Joe

[JoBwan]

Guys,
I had the spindle motor megged out, tore motor apart and completely insoected for opens or shorts. Motor checks good!! Put it back together. As for the Wye/Delta contactors, only the top contactor is energizing. shouldn't the bottom one energize after the spindle has started? Any help is appreciated.

[Wizzard of H]

You said: "...had motor megged out".
Do you mean an "megger" meter?
A simple ohmeter should be able to find shorts.
If it indicated a motor short, you should have found that when checking motor.
Was the short still indicated after assembling?

The wye/delta contactors are an alternating pair.
Only one is enagaged at a time.
One for low speed - wye winding.
One for high speed - delta winding.
Obvioulsy neither when machine is off and never more than just one.
Another test...

If you have the motor out or unwired, you can connect it to any 208-230 volt 3-phase shop power and it should turn at 1800 RPM.
If not, it's the motor. If it does turn, something else is wrong.
Use the Wye winding.
That is 3-phase power to 1,2,3 and 4,5,6 connected together.

[JoBwan]

Wizzard,
Thanks for your help!!! You and I were thinking the same thoughts through this process. Hooray!!!!! I'm up and running and I will share what I found to be the problem.
Parameter 57, Gearbox disable! The gearbox on this machine has some chattering in "low" gear, so they put it in high gear and then disabled the gearbox. The machine will turn @ 50 RPMs in high gear with "less torque" of course. Well, when installing the vector drive, we powered the machine down and the gearbox "Slipped out" of high gear and was registering in "low" gear. I had to re-initiallize the gearbox, Get it into high gear and then disable the gearbox again! Waalaa, going again!!!! The corredt fix is to replace the gearbox, but that's not an option right now. I hope this makes sense to everyone, as I had 2 different issues that occured during the same down time. Just an FYI, Chuck Golden has a tremendous knowledege for Haas machines and he is a certified technician.
Thanks for your phone call Chuck!!!