Hello guys  ,    i need to change parameter 1080  on control unit cu240e-2 .       I have to put in on 10  Hz  ,   but the parameter on the display is showing    0.000 r/min .   As i`m not familiar with this type of FC  ,  i presume it`s  rotations / minute  .   In this case  10 Hz should be aproximatively   285 rpm  ( motor is rated 1425 rpm)   ,  but  in what form i should put it into the module ?    Should be  0.285  r/min    or  285.000  r/min  ?  Siemens it`s a little confusing  :)

I want to change this because  motor is drawing  5 amps at 5% speed   (nominal current is 2.4 amps )    and i get a few alarms .The alarms are   :   F07900 ,    A07805   , A07409   , and frequency converter is stopping .  I`m thinking that  putting the minimum frequency higher  ( now it`s 0 )    the current will be lower and i`ll not get the alarms  anymore .

Motor is running at 400V  ,  1.1 kw , 1425rpm ,50Hz , 0.8 cos phi.

Any ideas  ?

Yes, p1080 is in rpm so put 285 here (if that's what you need).

What's the control type here? Why is the converter operating at 5% of the rated speed?
 It won't accelerate further or is this the actual setpoint?

What is the setpoint source here? I don't really understand the problem to be honest.

What do you want to do?

In what form can i put 285 rpm  there  ,   0.285    or   285.000  ?  This is confusing  because the original value is 0.000   .   is  "." a decimal separator?     Is 285.000  =   285 thousands or  just 285 rpm ?

The motor is attached to a pump ,   and it`s accelerating/decelerating  from 5% to 95% (HMI indication)   , in concordance with some stages ,controlled by a PLC   .   The problem is that at 5% rpm  ,  the current  is 2 times more than the  nominal current ,  and i receive alarms /unit is stopping .

That`s why i want to try to lift the minimum frequency ,   because at about 15% rpm and higher  i have smaller current . 

Hello,

From your description, it seems that Drive is controlled via PLC+HMI. You need to study PLC logic as well as HMI configuration, i.e. how motor speed is set via HMI, communication between HMI ---> PLC ----> to drive etc. etc.

BTW, is it new machine under commissioning or old running machine.

Please study below application example to understand the project well.

SINAMICS G: Speed control of a G110M/G120/G120C/G120D using S7-300/400F (STEP 7 V5) with PROFINET/PROFIBUS and Safety Integrated and HMI

HTH.

New question published by ndosh is split to a separate thread with the subject Have difficulty to change value P1080 during run condition.

Best regards
Jen_Moderator