Key Questions to Ask When Ordering Abb Acs880 Drive

Hi Guys,

I know its not directly PLC related but it is connected to my PLC

Just a quick one then, We have an ABB ACS800 Drive and when we change a parameter on the drive and then do a save (think it was 16.06) it comes up saved but if we cycle the power to the drive the parameter reverts to what it was before the change. I have also tried uploading to the keypad, changing the parameter and downloading back but it still wont keep the change after a power cycle. Any ideas? and Paramater Lock is Open.

Thanks Time to call or Tech Service on that one. I've had trouble doing that too and there is a specific order of keystrokes needed. Don't remember what it is. 16.06 LOCAL LOCK Disables entering local control mode (​​​​[FONT=Arial,BoldItalic][FONT=Arial,BoldItalic]LOC/REM [/FONT][/FONT]key of the panel).​[FONT=Arial,Bold][FONT=Arial,Bold]WARNING!​​[/FONT]​[/FONT]Before activating, ensure that the control panel is not
needed for stopping the drive!
OFF Local control allowed. 0​
ON Local control disabled.

If you're in local control you won't be able to use the disable local paramater, depending on version.

http://www05.abb.com/global/scot/sc...8fed25/$file/en_acs800_standard_fw_l.pdf

I'm fairly familiar with these drives if you need more help. OK, I believe that 99.02 is my problem it is set to Hand/Auto macro so tomorrow I will change the parameters I need to and then go to 99.02 and to a USER 1 SAVE and then change it back to USER 1 LOAD and hopefully when I cycle the power it will then work??

Cheers

Hello All,

This is not a PLC question. I deeply apologize for that but I am looking for help from great members like DickDV and others. I am new to this forum.

I work in a plant where we have winders and un-winders machinery. Each of those are built with ABB ASC800 drive powering 1 HP, RPM motor connected to 60:1 reducer. The drives are set in Torque Control macro and DTC function is activated. We run in torque control mode most of the time but sometimes we run in speed control mode. There is a switch connected between point X22.3 and X22.7 (I am assuming you can get a copy of ASC800 wiring diagram). If the switch, on in run on torque mode and if its off, it will run on speed control mode.

The problem we are having and its only on torque mode: at some points when the load speed gets too low (load speed gets too low when the material diameter gets larger) (load speed will be around 3 RPM at load side of the reducer and around 180 RPM at the motor side) the load will start to jerk. By that I mean it will not run smooth like when it faster. The reel will stop for less than a second and fast up again.

We have plenty of those winders and un-winders but we have the problem only on few of them. All of them were built using same exact mechanical parts and the drives were set the same way. Any advice? I would appreciate any help and reply.

Thank you One potential drawback of DTC (vs FOC) when run without an external feedback sensor (encoderless operation) is that because of what it takes to make DTC work, it is more subject to variations in the motor stator resistance. That resistance can then change with temperature. So what can happen is that at low speeds, some motors have a hard time cooling themselves, the stator temperature rises, and the DTC modeling becomes unstable.

You might be able to overcome this by adding an external encoder and doing closed loop control. I don't know this part from experience, it came up in a conversation I had with an ABB person once long after I solved my issue. I actually solved my problem by using an externally cooled (blown) motor. it looks like you are running the motor to slow
most VFD's running below 6 Hz will cog and when load is large it gets worse
a large dia. winder will be both heavily loaded and running at a very slow speed(Hertz)
the best solution would be to change the gear box to allow the motor to at a higher speed with a full winder. You can run the motor a up to 120 Hz when it winder is empty that should give you some room to play with. Thank you all for your input.

I still have the problem. I am sure adding encoder will fix the problem but that will be costly since I need to add encoder input card to my drives. What drives me crazy is I have more than 90% of them run flawlessly without encoder and under the same exact conditions.
We are using the drive reference button to set the torque and it will stay constant during the jerking but current will change of course. We usually set the torque reference at 18-25% when the load is not heavy. And once the load get heavier, we increase the torque reference to 30-40%.The ones that need higher torque reference are the ones show the jerking problem. Still sounds like the motor heating issue to me. If some work and others don't, it may be an ambient condition that seems insignificant to you, but makes a difference to the motor cooling. Look for blocked or obstructed air flows, radiant heat from other equipment, broken cooling fans on the motor etc. might even be a bad bearing and the heat of the hearing is transmitting to the windings. A vibration analysis might find something too.

It's not the issue of the drive clogging at low speeds. That happens with simpler V/Hz drives, but not with Vector drives or DTC as ABB uses. The drive is perfectly capable of making the motor run smoothly at any speed, even approaching zero speed. Instability at different winding temperatures however is a potential drawback of the DTC method. I agree that this should be an easy job for an ACS800 in DTC mode. The first thing I would check is the mechanical smoothness of the winder at slow speeds. If that is nice ad smooth, I would rerun the motor model but do it on the motor when it is fully warmed up. I have had a few test cell applications where warming the motor to operating temperature has resulted in a better motor model and better torque/speed management. I'd change the motor out before I would even think about an encoder. The ACS800 can generally manage smooth rotation at less than 1rpm so something else is causing the jerking.

Please let us know what you find. I than you are looking at this from the wrong side
at the slow speed where the instability starts the VFD is only running at 6 HZ very few if any can run at 6 HZ or below without an encoder and in Flux Vector Mode.
below 6 Hz you will never get it run stable the simplest solution would be to change the VFD out with a good Flux Vector one with an encoder and at that you still need to get a motor that can handle that low speed at full load without overheating
I have run a Flus Vector VFD down below 0.5 HZ running smooth enough to run a bead of weld that looks better then any hand weld. the gear box is just fine its just the wrong ratio