Created Date: February 23,2008

Created by: milldrone

LarsBest,

1. Has the GS2 been used somewhere else before?

2. Has the motor run previously before the GS2?

3. Please describe the load. Is it a conveyor belt lying in a steel pan exposed to rain? Is it a flexible impeller pump? The reason I'm asking this question is because some loads have a property I call "stickshun ". When the motor is connected straight across the line, the torque "snaps " the load free from the friction. But when the motor is ramped from stop (like what happens with a VFD) the torque cannot overcome the "stickshun ".

4. What is your setting for P0.01?

5. What is the motor nameplate full load amp?

6. What is your setting for P2.00?

The FLA is 3.9 and the motor never seems to pull less than 3 amps.

Are you saying the motor nameplate full load amps is 3.9 and the drive display is showing 3 amps. Or are you saying you have used an ammeter on the T1, T2, T3 and it's showing 3 amps?

I might be single fazing?

7. Regarding the single phasing question: Have you used an ammeter on all legs? This simple test will prove it.

The problem I am having is that sometimes the drive will not ramp up and if it is at a low Hz it gives me a OL1 fault.

8. Most commonly this is when the drive cannot provide enough amps.

Edit: Some more questions

I once worked as a third shift electrician, where there was a lot of pressure for production and no time for maintenance. There was a problem drive that would give an overload fault randomly without any apparent reason. The outfit also practiced a very strict lockout policy. Their answer to keep production up and to also practice lockout was to have a lockout disconnect (T lead) at every place an operator would need to access on the machine. (This is a good thing as far as safety is concerned a bad thing for the VFD). The other bad thing was there was one lockout disconnect that would randomly not connect all three phases. Sorry for the long story, but is there something that could break the connection between the drive and the motor?

Vaughn

Created Date: February 23,2008

Created by: LarsBest

The motor and drive are new. It is being used on a roller unit that is used for pressure vessel welding. I went down this morning and checked to make sure it was not single phasing. I changed P2.0 form high torque to general use. I also used 480V instead of 460V in the motor data. This changed my A at 6hz from 6-8 to a nice 2-3. We'll see how it does this week.

Thanks,

Lars

Created Date: February 23,2008

Created by: milldrone

LarsBest,

Ahhhh! The old voltage boost problem! This can be a non intuitive adjustment. Sometimes the results are better with no boost or even under boost.

Take a look at this thread over at PLCs.net http://www.plctalk.net/qanda/showthread.php?t=20220

For a little more in depth view of the problem.

Vaughn

Created Date: February 23,2008

Created by: LarsBest

I just installed a GS2 for a 3hp 480v motor. The problem I am having is that sometimes the drive will not ramp up and if it is at a low Hz it gives me a OL1 fault. The motor is connected to a gear box. I have ran it disconnected and connected. The FLA is 3.9 and the motor never seems to pull less than 3 amps. I thought on the way home that I might be single fazing? Any ideas?