Atv71

[YOUNUS]

Dear sir 

We are using atv71 drive for crane application long travel purpose 4 motors connected together each motor 5.5 kw

And vfd 30KW 

2 Motors near the panel and motors 30 meters faraway 

When we start the crane only current increase frequency remains zero.

If we disconnect 2 motors crane working fine. 

If 4 motors connect crane stops working???

Please me 

[BJacqz]

First idea I have from your description would be to check if motors are all running in same direction when you activate. To check it, disconnect 2 of them (see the direction), then test with two other one.

Another topic would be to check what is the current entered in the drive (should be the total of motors in paralell). What about the thermal protection, how is it done ?

[LeoLazzaro · Accepted solution]

Hi I think is necesary to reach the  local customer care center in your region  for this case, we will need more information, model of the drives , configuration , etc. 

I can recommend you :

                                    1) try to keep same cable distance

                                    2) check the sense of rotation of each motor , if you can check one by one  will be better . Maybe 2  of them are rotating  in opposite direction then when 4 are working current increase but no movement.

                                    3) check Motor control Menu parametrization as you have 4 motor in parallel you have to take care in the data that you enter in the drive , drive does not know that you have 4 motor , he see all motors as 1  bigger.  Test SVC and U/F to check if there is some difference . 

                                     4) I guess all motors are pulling of same load if you use SVC please put Slip compensation in 0% to share the load between all motors. 

Thank you 

B.R.

[Laureano]

I recommend having a look at the attached document.

[YOUNUS]

Thanks 

[YOUNUS]

Thanks 

[YOUNUS]

Dear sir 

We are using ATV 71 37kw drive for crane hoist application 

We are facing problem while crane down function operation sound coming from motor.

Up operation no sound. 

With loads little bit more sound. no load condition little bit less sound coming 

We check all mechanical bearings gear box every thing 

I feel motor sound 

Motor have encoder 

Parameter (Ctt) motor control type is FuC

Please give me some advice 

[PCDTC]

for heavy loads that need torque you should lower the ramp up time and dont start from zero hz make min frequency 5 hz at least