schneider altivar 71

[Jimsparky]

Hi looking for a bit of advice before i go back to this machine tomorrow.....

Got called in to change the inverter in the title as it had a fault with it (diagnosed by the manufacturer of the machine ??). changed it all no problems, switched it on and ran through its cycle fine but when it came to do a second cycle it should slow down in the middle of it let the product release and it didn't ??
I messed around with it for a while but couldn't work out if this should be in the settings of the inverter or the plc?
Any ideas on what to look at tomorrow would be great !
Thanks

 

[silva.foxx]

Personally I'd have thought the machine (or the PLC) will be signalling or referencing the inverter to suit the cycle. I expect the manuf. diagnosis to be correct, but if they're trying to diagnose from 200 miles away by phone... then they're only effective as the info they're given from the hands-on guy at the contraption!

It's probable, in my experience, that a sensor is at fault... perhaps an output from the PLC is missing as the code is not executing correctly (typically a flag, counter or timer bit not triggered). Again, that can't be correctly diagnosed from afar.

But... if the same is happening now as before the inverter replacement then I'd say the inverter is fine.

Something as simple as a loose connection, maybe.

If needed: http://products.schneider-electric....c-constant-torque/altivar-71-ac-drives/#tab=2

Good luck.

 

[Specialist]

Give the Machine manufacturer a ring & tell them the problem and the actions you've already taken, it might be a known problem with an easy workaround.

 

[Jimsparky]

Thanks for your replies. it is actually a different fault to the original problem. I find it more confusing due to the fact that it does the slow down on the first one but not after that but if you git the stop, reset then start again it does it again on the first run! Bloody machines! Im going to go in tomorrow morning and put a data cable in from the patch and let the manufacturer look into the program! Thanks for your help

 

[silva.foxx]

Were all the original inverter parameters copied over to the new one?

Were they correct to the last working version (unlikely to have commissioned values unless recently installed)?

If all is correct then the PLC holds the key!

 

[Jimsparky]

Yeah i copied the parameter over myself. they have two of these machines side by side so im also thinking of swapping these two inverters over and seeing if the fault follows the inverter. then ill know more. One day ill learn not to always say yes






fault shifts

 

[Knobhead]

If the speed varies in one cycle of the machine but not the next I’d be looking at the PLC.
One way to be certain is measure the reference supply to the inverter, be it 0-10V or 4-20mA.

 

[Jimsparky]

Thanks got this sorted. was a fault in the plc. ended up changing the analogue card and all ok now.
thanks for your responses

 

[Knobhead]

Thanks for letting us know. It's nice when we get feed back.

 

[silva.foxx]

That's a ditto on Tony's last comment!

 

[Jimsparky]

Not a problem. I really like this forum. their are other people out there that love this like i do !!!!