[aaroncaw]

Looking for help solving an ongoing problem with many of our Haas machines. Over the last 2 years our company has replaced about 20 vector drives to the tune of $2700.00 each! The alarms produced are all related to either Low DC voltage, Shorted DC buss etc because the control doesn't see the required 325Vdc buss for the servo drives at the correct level. The problem occurs after the machines have been powered off over a long weekend. All the "tests and checks" required by Haas shows nothing wrong. All voltage levels are correct, no drives are shorted, the only problem is that the signal coming from the Vector Drive itself is not accurate, or takes a very long time to reach a level that the control finds acceptable. If the level is watched (in diagnostics) and it rises above 300VDC, a "quick power cycle" can be performed and the machine comes up alarm free and will run absolutely fine until the next time it is powered down for longer than an hour. In all the cases we have replaced the drive, it was due to a concern that the machine will go down at a critical time and the replacement part will not be on our shelf. I have contacted Haas and they have acknowledged the fact that the problem is as a result of a component failure in the drive. Upon examination of our last failure, I found a small capacitor on the Power PCB inside the drive had burnt/failed. A simple 29 cent parts failure cost our company $2700.00 AGAIN!! Apparently this board ( that Haas Automation stamped on it ) is not available from Haas. I am looking for anyone who can help with suggestions for alternatives to replacing the entire drive. I would think that a company that prides itself on customer service would provide a more cost effective solution to customers who have over 200 of their machines.

[haastec]

Looking for help solving an ongoing problem with many of our Haas machines. Over the last 2 years our company has replaced about 20 vector drives to the tune of $2700.00 each! The alarms produced are all related to either Low DC voltage, Shorted DC buss etc because the control doesn't see the required 325Vdc buss for the servo drives at the correct level. The problem occurs after the machines have been powered off over a long weekend. All the "tests and checks" required by Haas shows nothing wrong. All voltage levels are correct, no drives are shorted, the only problem is that the signal coming from the Vector Drive itself is not accurate, or takes a very long time to reach a level that the control finds acceptable. If the level is watched (in diagnostics) and it rises above 300VDC, a "quick power cycle" can be performed and the machine comes up alarm free and will run absolutely fine until the next time it is powered down for longer than an hour. In all the cases we have replaced the drive, it was due to a concern that the machine will go down at a critical time and the replacement part will not be on our shelf. I have contacted Haas and they have acknowledged the fact that the problem is as a result of a component failure in the drive. Upon examination of our last failure, I found a small capacitor on the Power PCB inside the drive had burnt/failed. A simple 29 cent parts failure cost our company $2700.00 AGAIN!! Apparently this board ( that Haas Automation stamped on it ) is not available from Haas. I am looking for anyone who can help with suggestions for alternatives to replacing the entire drive. I would think that a company that prides itself on customer service would provide a more cost effective solution to customers who have over 200 of their machines.

You are asking a broad question to a potentially broad problem.

I have contacted Haas and they have acknowledged the fact that the problem is as a result of a component failure in the drive

Haas factory? What component? Who diagnosed this?

You have a 10% failure over 2 year period which leads to so many questions.
Is it the same component failure?
If yes, who is diagnosing?
Have you tried having a drive rebuilt by 3rd party vendor?
What is the environment of the machines?
What kind of preventative maintenance is performed?
How hard are the machines run?
How good is the incoming power supply?
What "Tests and Checks" specifically were done?
Do you have internal technitians working on these?
If yes, what are their qualifications?
and on and on and on ...........

Not saying that you don't have a problem, but like I said, a broad problem.

Pick one or two machines and discuss specific problems with specific questions, then you may learn the cause to more of your issues. Otherwise you are just talking about geneal issues which leads to a lot of speculation and "what if" scenarios with little productivity.

[aaroncaw]

Thank you for replying to my post. Sorry it has taken so long to reply, I don't get a chance to check this every day and I've been very busy.
To answer your questions, I will try to address them one at a time.
It appears that it is the same component that is failing. I have opened up the last two drives and found the same component, that appears to be a capacitor, on the Power PCB board inside the drive. No attempt to repair it was made and the unit was NOT Attachment 265190sent to a third party repair house. We merely "bit the bullet" and paid for the new drive.
I am a CNC technician with over 30 years experience working on various models of CNC machines.
The environment is clean. No restrictions have been placed on the cooling ventilation system of the drives until lately where we are purchasing the same filter setups used by Haas for the Vector Drive air inlets.
What preventative maintenance should be performed on the Vector drive? I am a Haas factory trained service tech and have used the Troubleshooting Form that has been used by Haas Techs for years. That form, even when used, proved nothing in the past. I am aware that there is a new form, however that form does not explore what the voltage is at P17 on the MOCON or MAINCON boards coming from the drive. In every case of our failures, the voltage at that plug was not representative of what the actual DC buss voltage was.
Incoming power is clean and there are surge suppressors installed on each machine.
Frankly, I understand that in extreme cases a 10% failure would not be an issue. However, 10% failure of a major component such as this, should be considered unacceptable. Especially since the "competition" experiences a fraction of the failures for similar components.
Either the component that is failing is "substandard" in some way, or a Recall of drives manufactured during certain dates should be done. I seem to remember Haas pulling drives manufactured between specific dates off service vans during my career with Haas.
Finally, in my mind, Haas is indeed one of the best CNC machines ever made for "every mans shop". It is hands down, the best "bang for the buck". I would just like to see a more cost effective solution to this problem.
I look forward to your response.

[Eldon_Joh]

That appears to be a tantalum capacitor and they are known to explode.

As to what else breaks after the cap explodes, or why it exploded.. i couldn't tell you... that depends on a host of other things.

as to the predictability of tantalum caps exploding.. it follows the 15th power of penny pinching CEO's. no, i'm not making that up.

[Ntolsen3]

Has anyone checked the Regen stack? This can cause pre-mature failures of the Vector Drive. I suggest replacing them and monitoring on a couple of machines.

Also verify grounds at the power panel. Although it may appear that the machine is grounded properly, I have found floating grounds at the breaker box. Try putting in a ground rod next to the machine and re-do the ground cable. This can cause issues as well.

[GITRDUN]

I would personally replace the caps in all the drives. We spent 4 years trying to track down an electric problem that was blowing caps and other electronic components in our machines and the problem turned out to be a power company issue. Suposedly they found a bad neutral somewhere on the grid around us, fixed it and problems gone. If capacitors are blowing consistently then you either have a whole batch of machines with weak capacitors hanging on by a thread or you have a power problem. Capacitors are usually rated for drasticly higher voltage than what they are used at, it takes a serious power spike to blow a perfectly good cap. Id put my money on a power problem or building wiring issue.

[Eldon_Joh]

Capacitors are usually rated for drasticly higher voltage than what they are used at.

That doesn't matter with the tantalum cap that blew up in the above photo. It could be the company found a cheaper capacitor and the manufacturer lied.
My boss got burned with some alleged 16 volt tantalums that were found to occasionally blow up whenever more than 9 volts was applied.
He has also had closed door meetings with company representatives who have admitted their datasheets aren't 100% true. I don't know which companies, and he can't tell me.

It may be that replacing that capacitor is enough to fix the unit, they do fail shorted on occasion and it looks like its on the output of an isolated supply that appears to power the gate drivers for the igbts or fets, whatever it uses.

Its possible that the unit senses the dc mains voltage downstream of the switches. so if that isolated supply failed it would not be able to turn on the motor, thus it thinks there is no power on the dc buss.

I would send the unit to a repair shop. how much are they worth to you? what have you done with the 20 that have been replaced?

[haastec]

Id put my money on a power problem or building wiring issue.

This was my initial thought also.

[electronic86]

hi, aaroncaw, checking your post i have a doubt on the image its not clear for me what is exactly the component or capaitor damaged please could you tell me the number in the write in the power PCB board for example c18, c25, i really appreciate your support, thanks and regards¡

[electronic86]

HI GITRDUN, PLEASE COULD YOU HELP ME TELLING WHAT IS THE CAPACITOR DAMAGED IN THE PCB BOARD VECTOR DRIVE???

[engine tech art]

Just replaced the HCPL7800A ( isolation amplifier) on the small board at the back of the dive you cant miss it and there it is! fixed all problems gone. Now to relocate the 20 risitors away from the HCPL7800A and maybe a cooling fan.
It even fixed the spindle fault when the first time i start the spindle.
Costed all of $40 with shipping.

The reason for this problem is the 20K resistors are too close the HCPL7800A ,temp limit is 85 deg. They now have to be relocated with a fan.

I had this problem since 6 months after Haas instaklled the drive. Called them they said too bad need a new one. Real Nice!

This is a SL 20 2000 with a 2007 smart drive.

[john-100]

I have always known tantalum capacitors are very sensitive to small voltage over loads or being reverse biased
these days I'd expect in most designs the tantalum capacitors can be replaced by ceramic and solid aluminum electrolytic capacitors

for more info if you can't sleep :-
http://nepp.nasa.gov/docuploads/1701...P%20report.pdf

http://www.nepp.nasa.gov/docuploads/...l%20Report.pdf

years ago I saw the result of a faulty tantalum capacitor setting fire to a PCB in a Aston 4 character generator used by broadcast TV graphics departments back in the 1990's


John

[GITRDUN]

Just an FYI. On most of the Haas machines i have worked on there is a parameter that can be turned on or off that monitors the voltage in the vector drive unit. This is where the computer gets its reading to make sure the power in the machine is not above or below the recommended levels. I have had numerous vector drives blow the circuit that sends the reading to the computer and then the machine will power up with an alarm and will not clear. You can disable this parameter and the machine will run fine, it just wont monitor the voltage anymore. The alternative is to replace the vector drive. Im sure there are tons of vector drives that have been replaced because of this problem. I have numerous Haas machines running that have that parameter switched off because they will not run with it switched on.

[Teckn9ne]

Just an FYI. On most of the Haas machines i have worked on there is a parameter that can be turned on or off that monitors the voltage in the vector drive unit. This is where the computer gets its reading to make sure the power in the machine is not above or below the recommended levels. I have had numerous vector drives blow the circuit that sends the reading to the computer and then the machine will power up with an alarm and will not clear. You can disable this parameter and the machine will run fine, it just wont monitor the voltage anymore. The alternative is to replace the vector drive. Im sure there are tons of vector drives that have been replaced because of this problem. I have numerous Haas machines running that have that parameter switched off because they will not run with it switched on.

Im digging up an old post but ran into this same issue, vector drive functioned fine, but the signal output did not match the DC BUSS voltage. My machine is an ‘03 VF7. The parameter i changed to make the control ignore the DC BUSS voltage is parameter 315 bit 8 should = 1. In service manual it’s called “mini mill” on my controller it was called “mini power supply”. I hope this is helpful to someone in the future.

[Donkey Hotey]

Im digging up an old post but ran into this same issue, vector drive functioned fine, but the signal output did not match the DC BUSS voltage. My machine is an ‘03 VF7. The parameter i changed to make the control ignore the DC BUSS voltage is parameter 315 bit 8 should = 1. In service manual it’s called “mini mill” on my controller it was called “mini power supply”. I hope this is helpful to someone in the future.

Interesting. Thanks for posting that. I'm curious if your temperature and coolant levels were also showing incorrectly. My 2004 VF-2 blew something on the analog-to-digital circuit on the MoCon board. All three values were showing all kinds of stupid values (coolant, voltage and temp). The solution was a replacement MoCon. That's the other end of what the Vector Drive is reporting a 'voltage' to.