More VFD Help Needed

[jteneyck]

Ken got his new 3 phase motor and we installed it this AM; heavy beast.  For testing, I routed 220V 1 phase line power to the VFD and the 3 phase output from the VFD to the motor.  I followed all of the programming shown in the video Mike posted a few weeks ago and set the motor amps and rpm to match the motor.  Pushed the run button on the VFD and the output says E.OC.A, which stands for Fault . Over Current. At Acceleration.  I tried changing the acceleration time from the lowest setting possible (0.1 S), to 3, 5, 10, 20, and 100 seconds, but the same code always showed.   

I haven't checked the internal motor wiring, as Ken said the tech. had set them for 220V input.  Probably should have, but I figured the guy would know what he's doing.  I know, never assume.  But assuming that's not it, there must be some setting in the VFD I haven't set right or haven't set at all. 

Anyone have any ideas?

John

[EricU]

is this a no-load start? I am having a hard time thinking about what this would be.  I would definitely check the way the motor is hooked up internally.

[Bit_Fiddler]

I had a similar, but not so intermittent issue on a Delta 2HP RAS that I put a VFD on.  Probably 3, maybe 4 times out of 5 the blade would stutter and then the VFD would shut down with over current errors.  I found that shortening the startup time actually reduced the occurrence of the error. but didn't eliminate it.   If I spun the blade freehand prior to trying again, it would almost always start.   I called FactoryMation's (I bought the VFD there) support line and they had me change a couple of settings in the VFD that increased current during the startup phase.  I don't recall the settings at the moment, but they knew what to do off the top of their head.  Might be worth a call to your VFD's support line or check their forums for the setting.

Dave

[cvillewood]

What VFD is it? There's not a lot to it so hopefully it'll be a simple fix. My first thought would be make it as simple as possible - no load on the motor, ninexternal switch, etc. is that where your at?

[EricU]

Pretty sure he is working with a Huanyang vfd. I'm trying to talk myself into going downstairs and working on mine, but a nap sounds better right now

[TDKPE]

I haven't checked the internal motor wiring, as Ken said the tech. had set them for 220V input.  Probably should have, but I figured the guy would know what he's doing. 

Famous last words.  


If you feel like it, pop open the motor's junction box, and write down (and post) the number combinations for the leads that are connected to each other, and to the incoming three power leads.

[jteneyck]

I checked the motor wiring and it is correct for 220v 3 phase. While in there I realized I had not changed the full load amp and rpm settings, so I did, from what was 13.2 amps to 13.5 for the new motor and from 3220 rpm to 3210. Seemed like minor changes but when I pressed the start button on the vfd it started to run. However, it tripped at around 2000 rpm and gave the same error message. I did it a couple of times, sometimes it wouldn't start at all, sometimes like I described above. The acceleration time is set at 3 seconds. I didn't have time to change it to see if that would work.

Oh yeah, it is a Huanyang vfd. At least we now know power will go to the motor. I'm guessing it just needs a small change to one or more of the settings and we'll be in business. I'm going to contact the rep. Ken bought the vfd from and see if he knows something, but input from you folks might resolve it just as quickly, so keep those ideas coming, please.

John

[Steve Evans]

Make sure the frequency is set to 60hz. It may be set to a default value other than 60hz

[EricU]

what was the video you used?  Did you reset to factory defaults?

[TDKPE]

A few things to look into: Is the volts/hertz ratio selectable, in and out? And is there a startup current limit, separate from FLA, or a multiplier that is adjustable? For normal operation at variable speed, the V/Hz ratio is constant, but there may be a setting for that. And Locked-rotor current, which every motor started across the line experiences when power is applied, can be 4-8 times FLA. We set our soft-starts on large (500 hp) motors that run on generators to never exceed FLA, but startup can take 30 seconds or more on some because of that. If the FLA setting is absolute, your motor may not want to play nice with the VFD - check the manual for some (separate) limit on starting current.

Oh, and there may be a setting for the current limit to be instant, or inverse-time, like a common home type circuit breaker (which has both, but instant is many times rated current).

Edit: A quick check of my WEG manual shows an overload threshold adjustment, from 1.0 to 1.3, which is above and behond the FLA value you set the parameter to. So check on such an overload 'tolerance' limit.