# Can PowerFlex 525 do synchronization and motion control?



## Zylonite (May 15, 2019)

I have 3 motors that need to have synchronized for motion and positioning. The VFDs used are PF 525, but Rockwell told me that we need to go with PF 755 drives. PF 755 are a lot more expensive than what we anticipated. Is there a way to do sync motion and control with PF 525?


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## just the cowboy (Sep 4, 2013)

Zylonite said:


> I have 3 motors that need to have synchronized for motion and positioning. The VFDs used are PF 525, but Rockwell told me that we need to go with PF 755 drives. PF 755 are a lot more expensive than what we anticipated. Is there a way to do sync motion and control with PF 525?


More info needed.

Are they mechanically hooked together?
What size motors?
How close in speed do they need to get?
Can they start separately or do they need to ramp up together?
You said motion how much change of direction? 

AB 755 can run in torque follower mode I think that is why they said to use them.

Cowboy


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## Zylonite (May 15, 2019)

just the cowboy said:


> More info needed.
> 
> Are they mechanically hooked together?
> What size motors?
> ...


The motors are induction 2HP motors
They are NOT mechanically hooked.
They need to be very close in speed (they control a large platform full of solar panels)
they all need to ramp up and ramp down together
they need to have synced FWD and REV directions at the same time

If one goes out of sync there will be structural damage


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## pudge565 (Dec 8, 2007)

I'm not sure why you would question the manufacturer on what you need for the application. They are much more knowledgeable on their products and the capabilities of them.


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## Zylonite (May 15, 2019)

pudge565 said:


> I'm not sure why you would question the manufacturer on what you need for the application. They are much more knowledgeable on their products and the capabilities of them.


because PF 755 is ten times more expensive (around $4k per VFD) and 525 is around $400 per VFD. Also it doesn't hurt to double check before throwing spending $12k on something that might be overkill....


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## pudge565 (Dec 8, 2007)

Zylonite said:


> because PF 755 is ten times more expensive (around $4k per VFD) and 525 is around $400 per VFD. Also it doesn't hurt to double check before throwing spending $12k on something that might be overkill....


Did you ever wonder why the 755 is more expensive? More capabilities that require complex electronics cost more... You seem to be insinuating that the manufacturer would steer you to a product that is more expensive just to make more money. While I agree that AB is expensive I highly doubt they would steer you to a way more expensive product for absolutely no reason.

And I will post here as well, based on this and other posts you have made, it seems you are in over your head on this. You really should contract this out to a controls company that has the knowledge to get you set up with what you need. I don't mean to offend you but it seems like, according to you, things will be damaged if this does not work properly. If you don't know what you are doing with it it is highly likely damage will result.


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## gpop (May 14, 2018)

3 motor with no mechanical interlock and you are planning to use 3 drives to keep things in-line. 

Making 3 motors ramp and run at the same time isn't a problem as you can hook all 3 to one drive but the whole idea seems doomed to fail before you start. 

This looks like a job that should be controlled via servo motors with active feedback on positioning or if slop is allowed 3 drives controlled by a plc that is monitoring the panel positions and correcting there positions.


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## oliquir (Jan 13, 2011)

pf525 are very basic vfd, cant do anything fancy with them, they are just used for standard v/hz application, if you need to make some sync with them you would need encoders and a plc to make motion control


on application like this it is often cheaper to use steppers motors or servo motors with their drives and now you can do whatever you need


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## paulengr (Oct 8, 2017)

525s can.be used as amplifiers only driven by a motion control card on a Logix PLC. Basically the encoder signal goes to the motion control card. The 525 gets Ethernet speed commands and the motion controller. closes the loop. If you slave then to a virtual axis you can synchronize as many as you want.

A cheaper version is to use analog master/slave control where the space 525 because just a current controller for load sharing purposes.

Steppers are all but obsoleted by PMDCs and BLDCs. These are best at low HP especially fractional and where you need minimal Wk2 (low inertia). All the comments about servo motors assumes the application is a typical motion control application under 10 HP. I’ve worked on 15 MW peak drives running 3500 ton robots where the servos were roughly 2000 HP induction motors. Induction motors can be usually don’t have great inertial or peak torque performance but the trade off is very low cost and ruggedness and almost infinite available size. Reluctance motors may eventually displace them but not yet.


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## paulengr (Oct 8, 2017)

paulengr said:


> 525s can.be used as amplifiers only driven by a motion control card on a Logix PLC. Basically the encoder signal goes to the motion control card. The 525 gets Ethernet speed commands and the motion controller. closes the loop. If you slave then to a virtual axis you can synchronize as many as you want.
> 
> A cheaper version is to use analog master/slave control where the space 525 because just a current controller for load sharing purposes.
> 
> ...








Sent from my iPhone using Tapatalk


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## Zylonite (May 15, 2019)

paulengr said:


> 525s can.be used as amplifiers only driven by a motion control card on a Logix PLC. Basically the encoder signal goes to the motion control card. The 525 gets Ethernet speed commands and the motion controller. closes the loop. If you slave then to a virtual axis you can synchronize as many as you want.
> 
> A cheaper version is to use analog master/slave control where the space 525 because just a current controller for load sharing purposes.
> 
> ...



PF 525 doesn't have master/slave feature


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## JRaef (Mar 23, 2009)

The PF525 was not designed to do this. It is a vector capable drive, but it has only a _*velocity *_vector control loop, it does not have positioning or torque regulator loops and you would need that for a task like this, _if you want any kind of decent precision_. But that's the operative issue here; lots of people are doing this type of task with 525s because the precision they are looking for is not as critical as it might be for doing it with something more capable. 

They probably suggested the PF755 if you said it needed to be precise, it IS designed to do this, in fact it is capable of making your motors act as if they are servos. 

BTW, someone is WAY off on your pricing!
PF525 is $892.50 *list *price (no way of knowing your discount but if you are paying $400, you are getting a deal)
PF755 is $2835.00 *list*, + the HIM and an I/O card unless you are doing Ethernet control only. Yes, more expensive, but not THAT much. The discount for a PF755 should be the same as for a PF525. $4,000 is almost 2x LIST PRICE!!!


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