Mazak V-414 + M32. Overvoltage error at spindle stop.

Hello friends.

I've had a problem with RPMs above 2500. Now the emergency threshold began to drop to 1800 rpm. From the obvious, we have a very long supply line and a voltage of 406V instead of 380V (we are in Ukraine). However, changing the jumpers on the windings of the main transformer (two steps down) had no effect.

Yesterday we tried to change parameter 26 (acceleration / deceleration) in Freqrol FR-SF-2-7,5K-BC - without success. This setting cannot be changed!?

Then we looked for the corresponding parameter number in the Machine Parameters of the NC. Unfortunately, nothing of the kind was found. Available documents do not describe all parameters.

We are at an impasse. Today I will check the brake resistors, but there are no errors from Freqrol. Please help. Please provide the numbers of the parameters that control the acceleration and deceleration of the spindle. Perhaps there are other ways to solve this problem.

Thanks.
Mike.

you need to check all drivers and FRSF power supply. Overvoltage alarm might be happening during deceleration with extra energy released from AC motor back into FR-SF spindle, and not able to be absorbed.

This alarm occurs if the spindle drive voltage detection circuitry senses a voltage of 400 VDC or greater on the
converter componets, also know as P & N of the base capacitor bank.


1) If the ALO.33 alarm comes immediately at power up, refer to procedure USA-E99651-004* located on the
Mitsubishi server.
2) If the alarm does occur at power up, check the incoming power to the drive with an oscilloscope and verify that it
is a clean sinewave with no noise and within the range of 200-220 VAC.
3) Possible instantaneous power failure or drop in the incoming power of the drive on deceleration of the spindle,
also check this with an oscilloscope.
4) Possible component failure on the regenerative converter side of the spindle drive. Contact Mitsubishi sevice
center for further insructions.
5) If all tests above check out good replace the top card (SF-CA).

I have no answers on the power issue, but want to wish you and your fellow Ukrainians all the best in this horrible war of occupation and thievery (including citizens!) started by russia. I'm very glad my country (USA) and the EU are helping, but I wish we were doing more.

Dear friends.

Thank you very much for your empathy and detailed answer.

Yesterday I took some time and researched the work of the recuperator. Two months ago I repaired Freqrol FR-SF-2-7,5K-BC. It was a huge accident. I upgraded the entire power section, control and power supply. Now it turned out that two modules did not function. That is, the repair was incomplete. Yesterday the shortcomings were corrected, the equipment worked at 6000 rpm without problems.

As for contacts with Mazak and Mitsubishi, the reality looks depressing. You don't need to expect any special support from them.

Good luck. And I think that I will have many more questions, because my work experience is only one month. :-)

MikePP said:

Dear friends.

Thank you very much for your empathy and detailed answer.

Yesterday I took some time and researched the work of the recuperator. Two months ago I repaired Freqrol FR-SF-2-7,5K-BC. It was a huge accident. I upgraded the entire power section, control and power supply. Now it turned out that two modules did not function. That is, the repair was incomplete. Yesterday the shortcomings were corrected, the equipment worked at 6000 rpm without problems.

As for contacts with Mazak and Mitsubishi, the reality looks depressing. You don't need to expect any special support from them.

Good luck. And I think that I will have many more questions, because my work experience is only one month. :-)

Click to expand...

like i said, converter was failing.

In all history, this is exactly what is surprising - a faulty converter. That is, with two faulty transistors, not a single error was displayed! And the manual and colleagues focused on the defect in the supply line.

I'm wondering - what other breakdowns can occur and what should be done for prevention?

that is exactly why you have to be specific in what you ask. And as I previously mentioned to check drivers and power supply.
If power supply has weak capacitors it wont provide voltage to fully ( read quickly) open and fully close IGBT to avoid across bridge inrush current when one part of it not yet fully closed and another one is already open.
Also some drivers might be doing bad job, not developing full scale positive and negative GATE voltage swing

Thank you, Mr. 777. Absolutely everything has been replaced, including modern IGBTs. Moreover, the gate control scheme has been completely changed - removed all gate driver microassemblies.
My question is broader - I'm interested in the machine in general. We have already had to repair the angle sensors of the axles. And I think there are many surprises.