I have Vacon brand inverter (5.5 CXS4A2IA) installed in one part of my Corrugator machine. The inverter controls the speed of motor which rotates a shaft having slitting tools. I want that when I enable the inverter and speed reference = 0V, it provide 5HZ output frequency to motor (like an idle speed) but there is no any parameter found except "Minimum Speed". When I set a value in this field, the inverter adds such value in out put frequency when I provide 0-10VDC signal to drive.

For example, if I set 0-10V = 0-100HZ, means 1volt = 10HZ and then set a value say 5 in "Minimum Speed", now drive provides almost 5HZ if speed reference = 0 but if I give a speed reference 1volt, the out put frequency, which should be 10HZ, increases at almost 15HZ.

Normally there is a parameter in inverters "Minimum Frequency" and if we set a value in this parameter, the drive provides same output frequency when it enables and the speed reference = 0V.

Please help how I can set the idle speed of the motor connected with this inverter.

So what you are looking for is a limit that does not affect the scaling of input V to output frequency??

Best regards,

Yes

AB2005,

I have an idea you could possibly try if you have a spare relay output and a multi-speed input.

If you set the a relay output (parameter 3.7) to "13: Output Frequency Supervision" and set parameter 3.9 to "1: Low limit supervision" and parameter 3.10 to 5Hz then this will output a signal if the motor frequency falls below 5Hz. This signal could be fed back in to the drive via an input (terminal 14 - DIB4) which is set up as a Multi-step Speed set to 5Hz in parameter 1.5.

This way every time the motor slows down to 5Hz the multi-speed should override the frequency and maintain a constant 5Hz. As soon as the frequency increases above 5Hz the relay output will change state and turn off the multi-speed allowing the drive to operate as normal. This way you wont have to adjust your scaling.

Worth a try anyway.

Cheers,

Shozza

Dear Shozza,

Thanks for a good idea. I did the same job as you mentioned but faced a problem. First I want to explain what I did;
Set P3.7 – 13
Set P3.9 – 1
Set 3.10 – 5
Connect +24DC with terminal 22 (common of Relay output 1)
Jump a wire from terminal 23 (NO of above relay) to terminal 14 (DIB4).
Enable the drive and found 5HZ out put frequency whereas Sp ref = 0V. Increase the Sp ref 0-5V but output frequency remained 5HZ while during normal operation 5V = 34HZ.
Now disconnected the wire from terminal 14 and again enable the drive with sp ref = 0V and found output frequency = 0HZ-increased the sp ref and found increment in output freq as a normal operation but when sp ref dropped down at the limit 0.735V where output freq was 5HZ (10V= = 68ZH) Relay 1 switched on and when sp ref increased from 0.735V, relay 1 switched off, remember I disconnected the wire from term 14.
Now I understood that freq limiter working correctly but if we enabled the drive with sp ref = 0V, the limiter switched on the relay 1 and ignore the sp ref signal. That’s why with wire connected at term 14, if I enabled the drive with sp ref = 0-10V (any value), out freq did not increase with increment of sp ref.

If any of reader want to help on this topic, see the manual in the link mentioned bellow.

http://www.kindel.se/produktkatalog/filer/VACON_ENG.pdf

I am still wondering what to do with my limited sources. Any help from any one?