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japcas
04-07-2012, 10:43 AM
Hey guys, I have a 2hp single phase input WEG vfd on my lathe. I've had it about 4 or 5 years now and haven't had any problems with it. Usually I flip the main power switch on and listen for the click of thd vfd and the display on it says ready, then I'm ready to work. The other day I turned it on and when it said ready, I hit the start button on the spindle and it wouldn't speed up. I had the speed pot turned up to around 60 hz and it was just barely running. I let it run and after a couple of minutes it revved up to the proper running speed and everything was fine. I replaced the speed pot thinking that may have been the problem but the pot is fine. Any ideas what could be causing this? Input voltage is good as I have checked that. I don't mind if it keeps doing this, but just wondering if it may be on it's way out and maybe need to start shopping for a replacement for when it dies. I definitely can't be without my lathe.

MaxHeadRoom
04-07-2012, 11:39 AM
It could be the main capacitor bank getting weak? Does it do the same on the manual/keypad entry?
Max.

J Tiers
04-07-2012, 11:56 AM
Is it running in V/Hz mode, or does it have a vector mode that you use?

It may have "decided" it needed to "learn" the motor again..... which takes a couple minutes, depending.

Weak capacitors are very unlikely to have caused a problem like that.

japcas
04-07-2012, 11:59 AM
It could be the main capacitor bank getting weak? Does it do the same on the manual/keypad entry?
Max.

It acts exactly the same using the local buttons on the vfd. I always run it in remote mode with a box that has the speed pot and start/stop buttons and reverse switch.

japcas
04-07-2012, 12:01 PM
Is it running in V/Hz mode, or does it have a vector mode that you use?

It may have "decided" it needed to "learn" the motor again..... which takes a couple minutes, depending.

Weak capacitors are very unlikely to have caused a problem like that.


It's been several years since I hooked it up and I don't remember what mode it is running in. Just seems odd that all of the sudden it has started doing this though.

MaxHeadRoom
04-07-2012, 12:40 PM
What model WEG is it? I have found that capacitors can cause various strange symptoms on most.
The smaller CFW-09 for instance, the DC bus is externally accessible and can be measured.
Also if using WEG it is nice if you can get hold of the PC software that is available, it help in trouble shooting or knowing what is going on in the drive.
Max.

japcas
04-07-2012, 03:28 PM
What model WEG is it? I have found that capacitors can cause various strange symptoms on most.
The smaller CFW-09 for instance, the DC bus is externally accessible and can be measured.
Also if using WEG it is nice if you can get hold of the PC software that is available, it help in trouble shooting or knowing what is going on in the drive.
Max.


A little more information about the vfd. It is a CFW-10, 7.3A, 200-240V model. It isn't throwing any kind of error messages either. Just takes a few minutes to have speed control.

MaxHeadRoom
04-07-2012, 03:46 PM
It does sound like you have a component problem in the drive.
If you have the parameters recorded, you could do a factory reset and start over, but that would be a long shot - last resort.
Max.

J Tiers
04-07-2012, 03:54 PM
Just takes a few minutes to have speed control.

Is this EVERY TIME then?

Does the thing light up and respond to buttons for everything except proper speed control?

japcas
04-07-2012, 05:02 PM
Is this EVERY TIME then?

Does the thing light up and respond to buttons for everything except proper speed control?

This happens at power up when I am going to use the lathe. The display shows "RDY", but when the spindle start button is pressed it will only run at around 50 rpms. I have the lowest hz parameter setting set to run it at 70 rpm minimum. Then after a minute or so it speeds up to whatever the speed pot is telling it to run at. It runs fine until the lathe is powered down and then it goes through this again. It's not a huge problem, I'm just wondering if the vfd is on it's way out and should I start shopping for a replacement for when it dies?

lakeside53
04-08-2012, 12:51 AM
if you're sure of the connections and programming, and can't live with the problem, replace the vfd... it probably has a failing component.

I have one that won't put the 10V for the pot externally, so I had to wire an external voltage regulator off the +24. Cost to "repair" is almost the same a new unit.

brandon
10-01-2014, 09:39 AM
CFW10 (http://www.ctiautomation.net/PDF/WEG/WEG-CFW10-Manual.pdf) is a newer drive from WEG. If your drive was sitting on a shelf too long without being used capacitors may need to be reformed.

MotorradMike
10-01-2014, 11:04 AM
This thread is 2 years old Brandon.