Mitsubishi Freqrol FR-SF

Hi Guys,
I Replaced the power supply (SF-PW) on this spindle drive about 3 months ago and it was working fine for the last 3 months. For the last 2 days the machine would just stop in mid cycle with a spindle controller error on screen. I powered off and back on and it worked for a while. then it stopped working completely.
The spindle drive LED's are all off . On closer inspection I un-plugged the 3 black therminals from the right side on the back of SF-CA Card. Powered up and all LED's working. I plugged back in the Terminal strips one at a time and it's only when the top one is in that the LED's go out. So the top Therminal strip is pulling the drive down. what can I do ? Should I try and trace where the wires from this strip are going, should I check or look for anything in particular ? The power supply LED goes down with the Card LED's too.

hopefully one of the EE's will step in here
but
'spos that may be blown base transistors?

Yep, it's one of the big base transistors gone bad. Mitsubishi Electric Automation (MEAU) has manuals on line, with procedures on how to check the transistors. A guy (in Malaysia of all places!) on Ebay sells the exact transistors you're probably going to need. 6 big ones on the accel side...you should replace all 6. The decel side uses (12, maybe) smaller ones...but they seldom go bad.

If you're not comfortable with this, MEAU charges about $2500 to repair your spindle drive.

Usually, when a base transistor dies, it will short out your SF-CA card as well. Sounds like your SF-CA is still alive. Lucky there.

MEAU gets about $700 to fix the SF-CA. I could fix one for probably $5, but MEAU won't sell their proprietary hybrid chip DK456, that is 99% of the time the culprit when the SF-CA poops.

Good luck, and keep us posted.

Greg

Thanks for the help Guys

Hi guys, The story so far....
I took out the spindle drive and downloaded the info from meau site, checked the transistors and saw that one of them was faulty. I ordered new ones and got them today. Thanks Greg for all the information and diagonising the problem. I got the transistors on ebay from Malyasia, only thing was that they weren't new they were used for sure (I'll chase that guy about that). I checked them with the meter and they were fine so I put them into the drive and put the drive back in the machine. Powered up and all looked good. Set up a job and the machine ran for about two hours fine. Then it stopped and I got the spindle drive malfunction alarm like before. LED's off on spindle drive. I figured must be a transformer again so I checked them but they seemed ok. Started machine again with the door of the spindle drive still open. It worked away for another while and I thought I'll close the door on the spindle drive. I did that and about 10mins later machine goes down again. This time the screen goes completely blank. So I took out the spindle drive again and I'm going to check all the transistors again in the morning. The biggest worrie now is that the controller and the screen are not coming on when I power up. (I insulated the cables that connect to the spindle drive as I did before so I could turn on the power to keep the batteries charged and it's an old screen so I like to power it on for an hour a day). Now as I said when I power up there is no lights on the controller and I can't turn on the screen at all. I can't find any fuses or trip switches anywhere but something must be gone somewhere. I checked two small wires going into the controller that have "AV in" written on them and I'm only measuring 60v accross them. What should I look for ? Is there a fuse or trip switch stopping the controller coming on ?
Thanks Guys,
I was hoping to have a better report, It looked good for a while there.

on these older mazaks if you push and hold the on button and then the screen comes up nothing but snow, it would imply a 24 volt short to ground. something like a limit switch or maybe a foot peddle or tailstock switch.
could also be the AVR or NC powersupply is dead.
could still be related to drive but your gettin' over my head on what.

Ok I found I was missing a phase !
The power cable into the machine had a wire broken. Sorted that now and screen and controller back up. I'm going to put the spindle drive back in now after I check the transistor modules again. So I'm thinking that maybe this loose / broken wire was loosing contact every so often and pulling down the spindle drive. Is this idea a bit crazy, like wishfull thinking ?

The only other thing I noticed was that the Spindle drive is displaying a different speed to the machine. If I turn on the spindle to 1000 RPM on the screen the Spindle Controller LED's are saying 1333 RPM . Can this cause a problem ? How do I correct it ?

Thanks guys.

Sounds like you may have her fixed...good job!

The spindle motor will turn a different rpm than your spindle, due to the different diameter pulleys. The motor pulley is smaller than the spindle pulley, to get more torque at the spindle. Thus the motor itself is turning more rpms than the spindle.

So, it is normal for the spindle controller LED to show different rpms than your cnc monitor.

That's weird the Malaysian-Ebay dude sold you used transistors. There are two different guys from Malaysia selling them on Ebay. I purchased some a year or so ago and they were new...maybe I bought from the other guy?

Either way, if the transistors test good, you should be good to go. Those MEAU test procedures for the base transistors are a bit tricky to figure out. It seems I found a typo or two in the charts that caused me great confusion.

So what I do now is test all the transistors in sequence, one at a time, and look for any differences in the analog meter readings. A bad transistor will have one or more totally different readings.

Greg

Thanks Greg,
So I won't worrie about the speed difference. I just was afraid that the spindle controller might have been in conflict with the NC control or spindle motor.
Yeah strange about the used Transistors, considering he has no negative feed back and pages of positive stuff. They came from Hong Kong so maybe he was all out and bought them somewhere else. I mailed him so I'll see what he says. They're working anyway.
It's nearly a good job ! runs for an hour or so then I get a spindle controller alarm, spindle drive is in a ready state as if I've just turned on the main breaker. power off and back on and it's fine for another while.

I'm pretty sure the problem is where the SF-CA card plugs onto the power supply. "Wippin Boy" spoke about a failure on these connections on one of my earlier posts. It's just a poor connection and I checked for connectivity with the meter and one or two are failing when I move or press the card a little.
I'm going to try and make these connections better tomorrow some how, not sure how yet though. I'll hopefully have it running perfect this time tomorrow. I'll keep yous posted anyway. Thanks very much Greg for all the help.

I saw on another post where you were saying about increasing the accellaration and decellaration times of the spindle to make it easier on the controller I would be interested in doing that. Is it a matter of changing parameters at the NC screen or is it changing parameters at the spindle controller ?

Thanks,
Mark.

I've been able to file that little socket just a touch and then poke a tooth pic in it to increase tension on that board plug, don't over file it
i highly recommend that accell/decell increase, helped my old fr/se's abunch
change will be on drive itself but I'm not sure how on yours
the se's are little dip switches but i believe yours is a two button programing deal
should be in those MEAU docs

The spindle accel/decel is set on the drive on the FR-SF, but, for T32 and newer machines, the control will default back to the standard setting when powering up.

So, you have to change a parameter, SP19 I think. (Check your electrical manual.) Original value on T32 QT's I have seen is about 300. I would change the parameter to 500, maybe even 1,000. After changing, power the machine down, and when powered back up, watch the spindle start and stop. When you find a value that you like, all ya gotta do then is make sure the control doesn't override the parameter when turning on.

About your drive alarming...if it is happening when the spindle is decelerating, you still may have some bad base transistors. Check the alarm code on the drive itself. Alarm 31 (or is it 32) is very common, the "Overcurrent-Inverter" alarm, and is indicative of either bad base transistors, a failing SF-CA card, or a weak SF-PW power supply.

Remember, the decel side of the drive has more base transistors (12 maybe?), and they are smaller. These decel transistors seldom go bad...it's usually one of the "big 6" accel transistors on the right side of the drive.

Also, visually check your capacitors (seldom go bad), and meter-check your 3 AC-to-DC transistors. (I forget the technical name of those little buggers..)

Greg

Hi Guys,
It's a good job now !
Working fine for the last few days. Got rid of the problem with the bad connection of the SF-CA card to the power supply and it's perfect. They's like a spring loaded clip on the card that plugs into the pins from the power supply. I gave the pins a rub of fine sand paper like you suggested Wippin' boy and tightened the clips a bit so the connections are good now.
I looked in my electrical manual and there's just a list of some parameters with the values they are set to but no explaination as to what they do. So I found parameter SP19 and like you said Greg it was set to 300. I increased it to 1000 and I can see that it takes a slight bit longer to reach the programmed speed. Not much longer but at least it might be a bit easier on the drive.
Thanks very much Greg for the information on changing the Base Transistors, I wouldn't have known that they were the problem and I wouldn't have known how to go about changing them if it wasn't for your help. Thanks for all the info and help. Your very well clued in on everything Mazak.

Good Result guys,
Thanks a lot,
Mark.

Hi mbpp,
I am just new in practical Machinist and need your help and information.
I have got the same problem as yours by this thread and wanted to know that which base transistor was dammaged by your controller and how you download the procedure of checking the transistors from MEAU???
Please advise me with above mentioned information.
Thank you.
Karan

Hi Karan,
To access the Mitsubishi Electric Automation Inc. - MEAU Home site I had to disable scripting on internet expolrer. To do this : open internet explorer, open the tools menu, click internet options, click security tab, click custom level, scrole to scripting and disable active scripting. When this is done close and re-open internet explorer for changes to take effect. Now you can access meau.com and click the downloads link and download all the doc's that you need.

You have to change these settings back afterwards for other things to work properly like your e-mail as far as i know.

I replaced all the 6 base Transistors as was recomended by Greg. I followed what he told me here :

"Yep, it's one of the big base transistors gone bad. Mitsubishi Electric Automation (MEAU) has manuals on line, with procedures on how to check the transistors. A guy (in Malaysia of all places!) on Ebay sells the exact transistors you're probably going to need. 6 big ones on the accel side...you should replace all 6. The decel side uses (12, maybe) smaller ones...but they seldom go bad.

If you're not comfortable with this, MEAU charges about $2500 to repair your spindle drive.

Usually, when a base transistor dies, it will short out your SF-CA card as well. Sounds like your SF-CA is still alive. Lucky there.

MEAU gets about $700 to fix the SF-CA. I could fix one for probably $5, but MEAU won't sell their proprietary hybrid chip DK456, that is 99% of the time the culprit when the SF-CA poops.

Good luck, and keep us posted.

Greg "


I bought them on e-bay here's the link:

NEW LOT OF 5 PCS MITSUBISHI UM150CDY-10 IGBT UM150CDY10 items - Get great deals on Business Industrial items on eBay.com!

The info on the meau site tells you how to check the transistors, it's in the troubleshooting manual i think. There's a bit involved in taking them out as you have to remove quite a few components, just make sure it all goes back the same way !

OK Karan, hope this helps and that you get sorted. Greg is the man on this, if you follow what he says you should get sorted.

Mark.

Hi Greg & Mark,
I am so pleased by your reply and information, I have found already the damaged IGBT and replaced it with another old one that I had from before but in a good working condition, every thing is right and machine is running well and I am ordering 12 pcs IGBT (6 pcs to replace with old one and the rest to keep as spare) actually I found the way to check the IGBT but with your recomendation to access to MEAU download-site I am going to download all the procedure from MEAU and perhaps some other more usefull information.
Any way thank you again and your information is wnoderful and very helpful to me.
Karan

I used to disable scripting in Explorer too,but the last time it didn`t work.Now I change the time zone of my computer to an American one and the MEAU site works easily.

Mark.

If you are losing transistors, Check all the voltages from the power supply there is 15 or more outputs. On the center and right side connectors power the base drive for the large transistors. Turn off the large breaker in the bottom of the drive while checking these. If one or more are missing the spindle will cog when running at very low speeds IE 20 RPM this a very easy way to check if there is a problem. If it continues to be run with transistors not firing properly it will eventually take out the first transistor to fire after the transistor that wasn't working. As noted above connection and power supply problems are very common. It is a good plan to verify that the replacement power supply is working properly by measuring these voltages when changing a PS, or if you are having problems with the drive. The repairs have gotten better the last couple of years, but a tech may miss a hair line crack that opens up during shipping.
Also there are 2 fans over the heatsink that can be removed without removing the drive from the machine. When they quit the drive overheats.

Hi Folks

I hope you guys can help me. I`ve got a problem with my Freqrol fr-sf spindel drive. when installed it runs up to speed just fine. but if we try and slow it down just a little, it trips emmediatly with Alarm 25 converter over current.

ps. Before this alarm I replaced the three big IGBT modules, one was faulty. There was also an optocoupler blown on the main board. tested the rest of the components on the main board. looks fine. compared the hybrids on the abi boardmaster plus.

anny further suggestions would be appreciated.

thanks Merlin

1.) Practical Machinist requires you list your location in your profile.

2.) It could be the current transducers. Square doughnut-shaped thingys that monitor current on the big wires, they can go bad. You must buy the exact same part number, as they are calibrated for different current levels. Buy from MEAU.

ToolCat

1). Sorry about that. updated my profile

2).there is two current transducers. To my knowledge it looks like one is used for acceleration and one for decceleration. I have swopped them arround and I still get the same Alarm.

Greg,
Hey buddy, I've got a number 20 alarm on my spindle drive (FR-SF-2-26K) and on the control side showing a number 19 alarm (SPNDL CONTROL. (BREAKER TRIP). The amber led is lit in the SF-PW. The machine is in E-stop state; any thoughts on what it could be?

Mike Ward.