Trouble running a AB Powerflex 753

Hello,

In my installation im trying to run a Powerflex 753. I however am having a little trouble running it at the right speed from the PLC.

I looked up the manual which describes using the reference command for speed. I have checked parameters 300, 37 & 520. These are set to Hz and both 60 Hz respectively.

However when I for example enter 30 in the reference tag, it will run at a very low speed with the run command. I expected it to run at 30 Hz like the manual describes. The feedback will show 0.05 and the output freq will show 0.

After using the jog command it will run at 10 Hz, the feedback and output freq will show this. I'm not sure where the jog speed is coming from tho, probably one of the parameters.

Is there something im overlooking or doing wrong? I have attached pictures to show what im talking about.

Thank you!

wesselvos said:

Hello,

In my installation im trying to run a Powerflex 753. I however am having a little trouble running it at the right speed from the PLC.

I looked up the manual which describes using the reference command for speed. I have checked parameters 300, 37 & 520. These are set to Hz and both 60 Hz respectively.

However when I for example enter 30 in the reference tag, it will run at a very low speed with the run command. I expected it to run at 30 Hz like the manual describes. The feedback will show 0.05 and the output freq will show 0.

After using the jog command it will run at 10 Hz, the feedback and output freq will show this. I'm not sure where the jog speed is coming from tho, probably one of the parameters.

Is there something im overlooking or doing wrong? I have attached pictures to show what im talking about.

Thank you!

Click to expand...

I believe it's expecting to see 3000 for 30Hz, but I could be wrong.

mylespetro said:

I believe it's expecting to see 3000 for 30Hz, but I could be wrong.

Click to expand...

As i have a lot of other Powerflex 525 drives, who do indeed expect 6000 for 60 hz, i've tried this too. However to no avail.

I also found the jogspeed parameter, which also only reads 10.

The powerflex 753 uses REALs for most of its data exchange, so you're correct, the speed reference should be 30 if you want it to run at 30Hz.


Have you set up the speed reference correctly in the drive parameters? You may be sending it a speed reference of 30Hz via a communication port, but if the drive is configured to get its speed reference from an analog input, it'll ignore your 30Hz and run at whatever reading is on the AI terminals - which will be pretty much zero, as you're seeing. Have a look in the manual at parameter 545. You can also look at read-only parameter 591 to see where your current speed reference is coming from, and parameter 592 to see what the commanded speed reference is.

I believe it's also possible to do some creative "blending" of speed references on the PF753 - e.g. adding the comms reference to the analog input reference, or multiplying one by the other - again, it's possible that your comms reference is being multiplied by an almost-zero analog input reference and resulting in an almost-zero overall reference. Somewhat unlikely, but worth looking at to eliminate absolutely if the usual suspects show up no possible causes.

Also, are you setting the direction to Fwd or Rev?

Just had this issue on a powerflex 755. if it's set up to receive speed commands over ethernet then it's working in jog because it's following whatever the jog preset speed parameter is. I had to combine speed ref 0 and 1 and set preset speed 3 to the speed I wanted it to run. speed ref 2 will follow whatever you set preset speed 4 parameter to.