# VFD wont auto start



## Abcanfield (Jan 15, 2011)

Three vfd's lost power and were in fault. Cleared the faults and only one responds in auto. The other two will only operate from hand button. They will not respond in auto. I've checked the signal power from the control relays and the signal voltage to the board is good. What am I missing?


----------



## Tristen (Aug 20, 2011)

Are the vfd's power flex by chance?


----------



## Hippie (May 12, 2011)

Check the settings and see if they are set to external trigger. Its possible they reset, check your other settings if this is the case


----------



## varmit (Apr 19, 2009)

Not many details to go on here, but if all of the I/O to the drive is working properly, I would GUESS that the control cards have failed. Depending on the brand and size of drive, the VFDs may be throw aways.

If you have a list of the parameters changed from default for these VFDs, check to see if some parameter has been glitched. Are these new? On some brands, if a "save" is done incorrectly, the drive will work fine until the power goes off the first time. Then it reverts back to factory settings.

Have you had any thunder storms or utility power problems recently?


----------



## Abcanfield (Jan 15, 2011)

Tristen said:


> Are the vfd's power flex by chance?


Power flex 400


----------



## Tristen (Aug 20, 2011)

Abcanfield said:


> Power flex 400


I had the same problem with powerflex drives a few years ago. Some of our powerflex drives wouldn't start after we lost power and I found if I just removed the enable and put it back then it would ramp up and work correctly from then on. If I remember right it was a setting that caused this problem. I want to say the setting had to do with auto start but I could be wrong. If the drive seen an enable upon reapplying power it caused the problem. Let me know if this helps


----------



## Abcanfield (Jan 15, 2011)

All parameters are set correctly.


----------



## Tristen (Aug 20, 2011)

Abcanfield said:


> All parameters are set correctly.


Were the drives enabled when the faults were cleared?


----------



## Abcanfield (Jan 15, 2011)

Tristen said:


> I had the same problem with powerflex drives a few years ago. Some of our powerflex drives wouldn't start after we lost power and I found if I just removed the enable and put it back then it would ramp up and work correctly from then on. If I remember right it was a setting that caused this problem. I want to say the setting had to do with auto start but I could be wrong. If the drive seen an enable upon reapplying power it caused the problem. Let me know if this helps


Thanx. I'll try that. The auto start setting A143. Are you saying disable, save, & then enable, save?


----------



## Tristen (Aug 20, 2011)

Abcanfield said:


> Thanx. I'll try that. The auto start setting A143. Are you saying disable, save, & then enable, save?


The drives I was having problems with we're powerflex 40's. Numerous times after clearing faults on them or replacing them I couldn't get the drives to start back up even if it was a brand new drive. We had a 24v enable going to the drive and then had a speed pot to adjust the frequency. For some reason if that 24v enable was present when a fault was cleared or if it was there when you applied power back to the drive it seemed to confuse the vfd. I removed the 24v enable from the terminal strip on the drive and then just relamded it and it would start working correctly. After this happening numerous times I found a setting that was different on one of the working drives. I thought it was something with auto start but I can't be sure now since where I work now we don't use these drives. If removing the enable wire and reapplying works I would check the advanced settings between the drive that started back up and the ones that didn't


----------



## Abcanfield (Jan 15, 2011)

Tristen, thanks for the input.


----------



## Tristen (Aug 20, 2011)

Abcanfield said:


> Tristen, thanks for the input.


No problem. We're you able to get them up and running????


----------



## Abcanfield (Jan 15, 2011)

Yes. Disabled restart attempts. Unlanded terminal 2. Relanded terminal 2. Enabled restart attempts to 01. Fixed. U da man!


----------



## Tristen (Aug 20, 2011)

Abcanfield said:


> Yes. Disabled restart attempts. Unlanded terminal 2. Relanded terminal 2. Enabled restart attempts to 01. Fixed. U da man!


Lol, thanks. The first time those drives did that to me I was in the same spot! That's good they are up and going now though


----------

