Need more info. Did you program motor info in start menu(para. 99)on vfd? Ramp up time if too short will cause over amping ,30 seconds is default. Program max amps in parameter 21. Is it the correct vfd for your application? VFD should be sized by motor amps and not by motor horse power.

 

Need more info. Did you program motor info in start menu(para. 99)on vfd? Ramp up time if too short will cause over amping ,30 seconds is default. Program max amps in parameter 21. Is it the correct vfd for your application? VFD should be sized by motor amps and not by motor horse power.

If drive sized correctly, most of the time I find ramp time to short, Just like Ken said. Also,ABB support is good though

 

Call the ABB tech support 1800 752-0696, see if you can get ahold of Bill Gahlman, he is pretty sharp.

 

Thanks! I found a couple of the big fuses on the bottom discolored like they seen a lot of heat.

Sent from the dust in front of you!

 

Yes we checked to see if the vfd was programmed correctly.. motor rpm and all. This vfd is seven years old. It was tripping at any given hz 20- 60. 6.3 up to 16 amps. It has been in the building 6- 1/2 years the motor changed once in that six. I'll go back through it tomorrow and check the ramp up speed off the top of my head.

Sent from the dust in front of you!

 

Is this from a dead stop or is the fan spinning backwards? If the drive doesn't have enough torque to start the wheel or reverse it if it's running backwards you will get that fault...

 

The vfd ramps the fan up to speed like it should[emoji43]

Sent from the dust in front of you!

 

There could be a few things causing this. Hard to give you a direction to go with limited info. Think about what could have changed if things have been running fine.
Has anyone had access to change parameters? Loose wiring? Etc?
There is a programmable option so the drive will stop the motor from free wheel spinning before starting it.

Mostly I find incorrect basic parameter programming. You say the motor was replaced. Was the drive programmed to match the new motor exactly?

How far is the motor from the drive? There is a parameter to compensate for cable length.

 

Yes the vfd was programmed to match the motors specs. The power lines are approx 20ft away from the motor with turns and bends. No shorts or loose wiring was found. Only issue found was the three big fuses had one side that looked cooked like when you heat steel and it becomes discolored. We suspect a bad static pressure sensor also. The high reading in the plenum was .6 different then what the ems was reading. Which would cause the vfd to ramp the fan motor up higher then needed. Even when the space temp was satisfied.

Sent from the dust in front of you!

 

I would think the false static sensor would not contribute to your problem. Sure the vfd may ramp higher but there is a max hz that is set. That being said I have programmed drives to run above
60hz.

I would call tech support to eliminate any parameter settings. I have always found ABB's tech support to be very helpful.

You could always try megging the leads for wire insulation problems. I have had that before.

Not sure about the fuse discoloration. Where are the fuses you are talking about? In between the motor and the drive? Also how is the motor connected to the line? Wire nuts or connectors?

Please keep us updated.

 

If its not settings and not the motor I would check the output with a scope and see if all three igbt's are balanced.

There is a way to force the autotune on the motor. If the drive is OK I would think it has something to do with inertia or lack thereof...