Powerflex 70 not accepting any frequency over 65hz

[Jonny1493]

Hello all, I am currently having an issue where the plant want's to decrease transfer cycle between roll beds.

I was able to achieve this by increasing the Preset Spd 1 (param 93 in this instance) from 65hz to 72hz. To achieve this I had to open drive executive and change that parameter manually. Increasing through the PLC wasn't registerting in the PowerFlex. I can control the speed through the PLC from 65hz all the way down to 1hz but increase it just to 66hz and it won't take.

FYI
Param 82 max speed = 75hz
Param 83 over speed = 10hz

If anyone has experience anything like this, any help would be appreciated.

 

[arpus4KM]

Hello all, I am currently having an issue where the plant want's to decrease transfer cycle between roll beds.

I was able to achieve this by increasing the Preset Spd 1 (param 93 in this instance) from 65hz to 72hz. To achieve this I had to open drive executive and change that parameter manually. Increasing through the PLC wasn't registerting in the PowerFlex. I can control the speed through the PLC from 65hz all the way down to 1hz but increase it just to 66hz and it won't take.

FYI
Param 82 max speed = 75hz
Param 83 over speed = 10hz

If anyone has experience anything like this, any help would be appreciated.

lots of variables here. are you sure you aren't being limited in the programming of the plc itself?

are you entering this through the HMI, or actually trying to type a new value in to the PLC?

if you are using preset speeds, is the plc changing the preset speed value? is the drive set to use the speed reference from the PLC or to use those preset speeds?

 

[Jonny1493]

I am able to send different values to preset speed 1 through the PLC, 65 all the was down to 1. However sending 66 through the plc, the powerflex doesn't acknowledge it.

When changing preset speed 1 manually through drive executive from 65 to 80, the powerflex will output that frequency to the motor.

 

[arpus4KM]

I am able to send different values to preset speed 1 through the PLC, 65 all the was down to 1. However sending 66 through the plc, the powerflex doesn't acknowledge it.

When changing preset speed 1 manually through drive executive from 65 to 80, the powerflex will output that frequency to the motor.

I understand that, but that doesn't mean you don't have something limiting your maximum within the program itself.

If you change that value through drive executive, does that show the same change in the program where you can't increase beyond that point?


I've seen plenty of different ways it's accomplished, some do limitations on the drive, which yours doesn't seem to have. Others have it set in the HMI through input limits.

and then the last that I think you may have. is somewhere in your program, you have a value check seeing your input, and if it's greater than 65, then it's reverting to 65.

I would verify there is nothing like that first. because if no limits are set on the VFD then it's being commanded back down somewhere else.

 

[arpus4KM]

can you post the program up?

 

[Jonny1493]

Solution has been found.

You can change parameter 82 in drive executive all you want, but for the VFD to accept the change you have to power cycle it.

Param 82 max speed before the change was set to 65hz, any speeds above 65hz were ignored.