[Scrambled1]

Hi all-

I have been busy and not worked on my Hurco MD3 in several months.

I have been having problems that I am slowly working through. So here is the latest.


I think the VFD is a Yasakawa drive. The VFD does not have a name on it, but according to google it is a Yasakawa.

The model is a CIMR-7.5B.D06.

All I had to do was face some nylon blocks off. So I fired up the mill, turned the mill on and by using the x,y, and z buttons faced 6 out of 12 blocks that are 2 x 6 inches. Easy enough.


Then the faults started. I started to get a UV1 fault flashing on the VFD. If I cleared all the faults, and started the spindle right up, it sounded like the bearings were out, and about 5-8 seconds later the UV1 fault was back.

If I waited 20 minutes, the spindle sounded great, then I could face 5 more. Then faulted.


Any Ideas?


I am looking for information about the VFD, but can't find anything.

Any Ideas?



Steve

[underthetire]

Uv is under voltage I believe. Did you check yaskawa web site? They usually have all the manuals for download, and free software for troubleshooting.

[Scrambled1]

Underthetire-

I called Yasakawa earlier today, and they are looking for a manual for me. But so far, nothing.

I did some snooping on the drive and found some switches. There was a label on the inside cover that had "recommended settings".

There are several switches are not in the "recommended" position.


Here are the ones that are different

V/F patterns now 0 suggested 1
Sequence mode now B 0
electronic overload F 6

dynamic braking on off
braking resistor on off


then there are 2 pots for Acel 4 decel 2


I hope someone can point me in the right direction




Steve

[underthetire]

Don't change parameters! Hurco set them up for the hurco interface. There is also a small fan inside those, maybe check that first. I would however write down all the parameter settings now, that way if you need to get the drive repaired or it goes up in smoke you have a chance to fix it.

[Scrambled1]

I am not going to change anything, but I bought this mill as a non working mill. I am not sure what the person before me has done.

Besides a few small items I do have it working, it is just slow going.

Do you think the UV1 is input, or output? If it is input, then I might have a bad contactor or overload heater.

If it is output, not sure what to try



thanks



Steve

[underthetire]

According to my Yaskawa manual, Uv1 in DC buss too low. Check the incoming power supply.

usually i see this from supply wire too small feeding the machine.

[Scrambled1]

Underthewire-

So far I can only find the manual for the H2. According to Yaskawa, it "should" be the same.

Some place I found a reference to UV1, and it said it was a voltage drop to the motor.

So I am still looking.

I am running this mill on a large CNC rated 20 HP rotary phase converter.

I have also rewired it, just to make sure the created leg was messing with the mill.

Any other ideas?



Steve

[underthetire]

Have you monitored the voltage at the machine before and during this condition?

[scrambled]

Underthetire- I checked the voltages a few days ago, but I don't remember what they were. When I get to the shop later tonight I will get the incoming voltages along with the VFD output voltages.

Steve


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[Scrambled1]

Underthetire-

you might have pointed me in the right direction. The voltages with the spindle running are L1 AND L2 236 volts, L1 AND L3 241 volts, and L2 AND L3 248 volts.

When the spindle started acting up and faulting, the voltages dropped to 224 between L1 and L2.


Looks like it is time to try to balance the phase converter



Steve

[underthetire]

Yep, waaaay to out of balance and you may be way over the max voltage. Thought those were 220 machines +/- 10%?

[scrambled]

Under thermite- if it is a dc buss low fault, would that mean the capacitors are bad?

I am also looking for a megger to check the motor.

I am changing the wire anyway, it needed to be rerouted.

Steve


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[scrambled]

Oops

Should have been-underthetire- Auto spell correct got me


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[underthetire]

Yes, but bad power in=bad power out. Typically, if the rectifiers are bad, or the caps, you will get that alarm at first power up and not be able to run. You may end up putting buck boost transformers on to get a better matched incoming voltage. What size wire did you use to the rotary, then to the machine? How long of run? What's the kva on the machine?

[scrambled]

Underthetire-

I have had to put the hurco project on hold for about 2 weeks.

I got a large handrail job I have to finish.

I will let you know when I get back to it.

Thanks for the help



Steve


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[scrambled]

Underthetire -


I was able to run new wire from the phase converter to the mill. I used #8 wire and removed the twist locks.

I also cleaned all the fans and made sure they were spinning correctly.

I started the spindle and it faulted after about 8 minutes. It still gets the UV1 fault.

Steve


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[scrambled]

After saving my pennies for a month or so, I was able to get a toshiba S15 VFD and get it installed.

Works great. I have played around with it for several days and no faults at all



Steve


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