VSD Problem in Tape Wrapping Machine

JRaef is probably your best bet. He is the drive guru on this forum.

I'm pretty familiar with Yaskawa drives but just not that model. I've found a manual for it and it looks very similar to the A1000. Zero servo functionality is only possible in closed loop vector (CLV) also known as flux control - Parameter A1-02 set to 3. From memory if you try to set a parameter that is not available in the currently selected control mode the display just flashes angrily at you.

I think you are correct that the A1000 and H1000 are very similar. When I was hunting for the replacement, the sales guy at Teco Aust offered us an A1000.

The support guy at the OEM's office in Shanghai offered the H1000. We took this because the OEM knows best, right?

The new drive seems like a newer version of the dead one, there are a few extra settings but almost all of the old drive settings map into the new without any real head-scratching.

Parameter A1-02 is set to 3 for closed-loop vector, checks with old drive.

Drive will not take '72' as the setting for H1-04.

Tomorrow, I will get my test laptop back from an away mission, and I will be able to connect to the drive using the Yaskawa software. I'm hoping that will show me something new.

Interestingly, the machine actually functions ok without the zero-servo enabled, it may be that it is only used for a crash-stop when the e-stop is activated

One hopes that the OEM's invoice hasn't been settled yet?

Does your VFD have a 0 to 10vdc or 4-20ma or is it a servo drive? Have you tried to hook up another type of drive to the computer to see if your speed control will migrate. Try asking a Distributor to bring a demo and tell them that if it works you will buy replacement parts from them. What kind of PLC does your Chinese machine have in it and what output gives your motors the control signal?. To bad you can't provide pictures.

So we got a resolution to this problem yesterday.

I had attempted to connect to the drive with our test laptop but it didn't want to play due to the way that IT had set it up (grrrr).

We got some help from a guy who is well experienced in machine repair, and his laptop connected to the drive.

Once we could see what was going on in the drive, we could see that the problem was that it could not see the encoder card. After much head-scratching and a more careful read of the encoder card manual, we found a wee footnote that said that the card needed to go in slot 3, not slot 2 where we had it. Shifted the card and all came right, the drive could see the encoder, and so would accept settings for closed-loop vector.

The tape machine is now back in production, with a couple of lessons learned.