Powerflex70 and drive overload fault

[DaveW]

I have a PF70 that keep going into drive overload fault (F64) a few seconds after it is started. This happens even when we disconnect the motor. I even copied the parameters via the HIM from an identical drive that is working. Any idea? Thanks for any advice.

 

[mrlucmorin]

Hi,

Is this a brand new unit you're trying to comission ? Or is it a unit that used to be working and now stopped ?

If you have another working unit, you could swap the two, and see if the problem follows the faulty drive.

 

[averellen]

We started upgrading our AB 1336 drives with PF70's.
The brake resistor required is different. We initially had overload faults until we put the correct brake resistor in.

 

[AJZ]

Can you increase the acceleration time?

 

[DickDV]

You stated that the copy procedure put the same software into each drive. Are the two drives rated the same? And are the motor nameplates exactly the same? If either of these two answers is no, duplicate software will not be appropriate.

If both answers are yes, then the drive is most likely defective.

 

[DaveW]

Thanks for all the replies. Yes the drive is brand new and was working for a few days. We have 3 same size drives running the same size pumps. I will try and increase the accel time but don't think it will make a difference since no motor is connected. Would break resistor be required for pumping application? We're running 3 pumps to maintain pressure in a cooloing tower application. Thanks.

 

[mordred]

try increasing the ramp time then in the menus you should be able to find a current reading. Also make sure all your phase legs are balanced both input and output. The 1336 vfd is a senserless vector drive I beleive the powerflex can be configured as such make sure its set to the correct drive mode. Then check and make sure all you drive information is correctly configured in the basic drive setup menus including the max current setting should be 150% FLA. Although if the drive is going into overload faults without a load I suspect you may have a faulty drive (ground short on the drive)

 

[MartB]

Thanks for all the replies. Yes the drive is brand new and was working for a few days. We have 3 same size drives running the same size pumps. I will try and increase the accel time but don't think it will make a difference since no motor is connected. Would break resistor be required for pumping application? We're running 3 pumps to maintain pressure in a cooloing tower application. Thanks.

Although you say it's been working for a few days, I wouldn't rule out a bad drive. I've had several drives that I've had to replace after the first week in the last 7-8 months. Just a thought.

 

[mrlucmorin]

Thanks for all the replies. Yes the drive is brand new and was working for a few days. We have 3 same size drives running the same size pumps. I will try and increase the accel time but don't think it will make a difference since no motor is connected. Would break resistor be required for pumping application? We're running 3 pumps to maintain pressure in a cooloing tower application. Thanks.

Normally a wrongly sized brake resistor would not give "Overload" errors. Most likely you would get "Bus overvoltage", or you would damage the brake transistor.

Often times I've had to reset drives to their factory default. If you poke long enough at the parameters, you're bound to touch something you shouldn't have

Try a reset and reprogram of the drive. If it doesn't work, you shouldn't rule out a bad drive just because it's new.

Regards.

 

[Rube]

We recently used some PF 4Ms that started having Drive Overload faults. We had to change the boost voltage parameter to zero even though we'd never had to using the original PF4's on the same type Baldors. Might look at that first?

 

[DickDV]

Your drive is bad. After re-reading your original post, a Drive Overload Fault without the motor connected is curtains for the drive.

 

[OkiePC]

I agree with Dick, if the drive "thinks" it is overloaded even with its outputs opened, it has a serious problem, but I have seen them act weird when set up for sensorless vector and not autotuned.

So if it still won't run in V/Hz mode or after successful autotuning, then replace it.

 

[DaveW]

We disconnected the motor leads from the drive today and was able to run the drive all by itself so I'm guessing the problem is in the wires between the drive and the motor local disconnect. Maybe the disconnect is bad as well but we will have to test that out and see. Thanks for all the suggestions and help.

 

[Lancie1]

I was going to say, "make sure the motor leads are really open, not just disconnected at the motor, because I have seen short circuits cause a drive to act this way.". But you figured it out yourself.

The bad news is that a short circuit can damage a VFD, if the overloads are not set correctly.