Power flex 753 inverter how to program for preset speed.

[Saudi jamal]

Hi guys, thanks to all for helping me.
2000kg/hours potato frying(chips line) burner 30 kw fan motor getting trip when it is working on boil out mode.Boil out mode fresh air damper is fully opened and it is tripping when it is at 50 hz.But our observation frying mode motor is not getting trip due to fresh air damper is fully closed.so at the moment we reduce maximum forward frequency to 47 hz and motor is not tripping in both mode but we are facing a problem that combustion chamber temperature goes to high from 630 deg cen to 830 deg cen and hot steam is not
sucking completely because we reduce frequency.
weekly one time for 8 to 10 hours we are using boil out and other time it is working in frying mode.
so now we planning to run the motor in two speed.one for boil out and other for frying mode.
4-20ma analog output coming from plc.i dont like to distrub the original circuits but i would like to add one preset for boil out mode running as per preset value.
we are using 2 wire control.we dont installed any input/output card.only one DI2 is spare.only one preset is requird.
kindly see my past posting circuits diagram and inverter control terminal.
kind regards and appreciated for you valuable time.
jamal.

 

[OkiePC]

...
so now we planning to run the motor in two speed.one for boil out and other for frying mode.
4-20ma analog output coming from plc.i dont like to distrub the original circuits...

Based on that information, I would definitely just edit the PLC logic to accommodate your speed change trial. Unless there is some really good reason you can't do it with PLC logic. Leave the drive wiring exactly as it is and write some logic which will do what you want, be easy to adjust or revert if it does not work out.

Having analog speed command from the PLC will provide you with the utmost flexibility and adjustability.

 

[Saudi jamal]

Hi okiepc,
i dont have rslogix 5000 programming knowledge.i can do only micrologix
and slc500 upload and download and minor modification on digital input.but still i am trying to learning plc programming and i hope it will take time.
at the moment without plc programming how can i run the motor with two speed.one reference from plc anlog input and other from digital input preset selection.di2 is now free.
kind regards.
jamal.

 

[dipesh9486]

Still not understand your problem if your requirement is 2 fixed values ie:50 and 45 Hz why are you using analog reference value.
There 2 way to do things in working way.
1. Remove or overwrite the analog reference functions and move the preset values in drive's frequency register.
2. Use fixed speed architecture of drive, for that you have to reprogram drive not whole parameters but offcourse the frequency reference and fixed speed input parameter and after that you can you a direct push button or a toggle button as you mention in your previous post.
Thanks.

 

[Saudi jamal]

Hi guys,
I have good news that today I was able to run the motor by two speed. Thank you very much for those who helped me.
Special thanks to Mr.dburnum and Mr.jraef.I was following both of your instructions and your instructions
Make me very Happy and completed my job.
I give one digital input 2 and set 2 parameters like parameters no.550 and PR 173.
Thanks and. Kind regards.
Jamal.