# Abb acs 800



## JRaef (Mar 23, 2009)

anuragpattanayak said:


> We are using a 37KW ABB ACS 800 VVFD to drive a three phase motor of same capacity. The motor drives an unbalanced load. Problem is the drive cannot start the motor. The load keeps on oscillating and comes to stand still. We have kept the initial starting limit at 600 RPM , only then it starts.
> 
> Any other suggestions?


Did you perform an Autotune of the DTC control parameters on that drive connected to that motor? The symptoms you describe sound as though that is the case. If not, the drive does not know how to best control it. If you are using this in V/Hz mode (non DTC), then you have wasted your money on paying extra for the 800, you could have used the 550. Still, for an eccentric load, you will want to use DTC control, but it needs to have a mathematic model of the motor to accomplish it. If you know EVERYTHING about that motor, for instance the transient reactance, etc etc., then you can load it manually. But it's a better idea to use Autotune so that the drive tests the motor itself and creates the motor model. It means decoupling the load though.


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## anuragpattanayak (Mar 21, 2013)

dear Sir,

We did ID Run in DTC mode. 

No idea , why the motor is not able to drive the load. Some times it does, some time it doesnt. 
We have kept the starting minimum speed of 400 RPM.
Dc magnetization is not a solution ,since injecting dc will be bad for motor (IMO).

Any other solution , as in how we can start the motor at a lower RPM?


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## anuragpattanayak (Mar 21, 2013)

JRaef said:


> Did you perform an Autotune of the DTC control parameters on that drive connected to that motor? The symptoms you describe sound as though that is the case. If not, the drive does not know how to best control it. If you are using this in V/Hz mode (non DTC), then you have wasted your money on paying extra for the 800, you could have used the 550. Still, for an eccentric load, you will want to use DTC control, but it needs to have a mathematic model of the motor to accomplish it. If you know EVERYTHING about that motor, for instance the transient reactance, etc etc., then you can load it manually. But it's a better idea to use Autotune so that the drive tests the motor itself and creates the motor model. It means decoupling the load though.




dear Sir,

We did ID Run in DTC mode. 

No idea , why the motor is not able to drive the load. Some times it does, some time it doesnt. 
We have kept the starting minimum speed of 400 RPM.
Dc magnetization is not a solution ,since injecting dc will be bad for motor (IMO).

Any other solution , as in how we can start the motor at a lower RPM?


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## John Valdes (May 17, 2007)

Adjust the ramp time and see if that works. Have you programmed the motor data?
How do you know if the drive is of sufficient size to do the job?
Sized properly?

How about the load? Are you starting the motor under full load?


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## anuragpattanayak (Mar 21, 2013)

John Valdes said:


> Adjust the ramp time and see if that works. Have you programmed the motor data?
> How do you know if the drive is of sufficient size to do the job?
> Sized properly?
> 
> How about the load? Are you starting the motor under full load?


Ok will do that .

Yeah drive is sufficient and we have programmed the motor data.
Thing is once the unbalanced motor makes a single complete rev..the drive runs properly and with the current limits ie normal operation.

No , we havent yet full-loaded it. Its only motor-belt-euipment and no iron ore over it


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## John Valdes (May 17, 2007)

Have you contacted ABB?
That is where I would go first. Before coming here.
Its their control. Is this a new setup? If it is, contact ABB or the vendor and get feedback from them.
They do help if you ask them. Especially the vendor. They use these problem calls as opportunities to get into a facility.
Take advantage of this. I know they will.


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## anuragpattanayak (Mar 21, 2013)

John Valdes said:


> Have you contacted ABB?
> That is where I would go first. Before coming here.
> Its their control. Is this a new setup? If it is, contact ABB or the vendor and get feedback from them.
> They do help if you ask them. Especially the vendor. They use these problem calls as opportunities to get into a facility.
> Take advantage of this. I know they will.


Nope would call them..if i cant solve it. Actually it is march end..so thought may be i could solve it and get some bonuses


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## JRaef (Mar 23, 2009)

anuragpattanayak said:


> Ok will do that .
> 
> Yeah drive is sufficient and we have programmed the motor data.
> Thing is once the unbalanced motor makes a single complete rev..the drive runs properly and with the current limits ie normal operation.
> ...


If by "programmed the motor data", you mean that you have just entered in the motor nameplate information, that is NOT the same and is NOT sufficient for the drive to be able to accomplish DTC. 

Look, DTC, like Vector Control, is capable of making that motor put out 100% torque at nearly zero speed and full Break Down Torque (>220% of FLT) for short periods. So if the motor is capable of lifting the eccentric weight at 600RPM, or 400RPM, it is equally capable of doing it at 1 RPM or 10RPM. The fact that it is not is prime indication that it is NOT operating in true DTC mode. If the drive has the wrong or incomplete motor model, it is no better than a V/Hz basic drive, therefore it does not "know" that the motor is not turning. So you are compensating for that by increasing the speed, which eventually produces enough extra torque to lift the weight and start it. 

You say that you enabled DTC, that's fine. But I asked you if you did an Autotune, you responded that you entered the motor data. That is NOT the same thing. There is technically a way to enter the EXTREMELY detailed information about the motor's magnetic circuit characteristics into the drive, as opposed to letting it test the motor with Autotune and determine it for itself, but that kind of information is NOT on the motor nameplate, and is often very difficult to attain even from the motor mfrs. To give you an idea, there are around 20 different motor data parameters you would need to enter manually, not just the minimal stuff that is on the typical nameplate like Volts, Hz, FLA, PF, Efficiency, RPMs etc. That is why Vector and DTC drives have the Autotune feature.

So did you perform the Autotune or not?


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## anuragpattanayak (Mar 21, 2013)

I am sorry to sound like a newbie (which i am )

is autotune same as ID run? or there is a different parameter to auto tune ACS 800?


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## anuragpattanayak (Mar 21, 2013)

@JRaef 

Hey JRaef , i figured out what is Autotune and it worked well! now i can start the drive at 1RPM. 
I autotuned the drive with empty load(only euip). Can i autotune it again with load (equip+raw material)? or it wont require an auto tune again?

Thank you so much


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## JRaef (Mar 23, 2009)

anuragpattanayak said:


> @JRaef
> 
> Hey JRaef , i figured out what is Autotune and it worked well! now i can start the drive at 1RPM.
> I autotuned the drive with empty load(only euip). Can i autotune it again with load (equip+raw material)? or it wont require an auto tune again?
> ...


No you should not need to do it again. You can sometimes do it with the load coupled, but you must be able to run it at a constant speed of 20% for 30 seconds, and with an eccentric load it may not be stable. If it works now, it should work with the load coupled as well.


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## chrish (Apr 12, 2012)

Here's the user's manual.


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