ronny_resistor
Member
Just wondering if anyone can send me a simplified Torque setup for a 40HP Allen Bradley 755 Powerflex drive. I worked all day manipulating what a previous engineer has done and it makes no sense.
The previous engineer installed 97.5 Amps as a current limit whereas the drive has a 65 Amp limit. (Par 411 ad 412) I changed these back to the maximum motor limit which is 65 Amps. My Torque min and max is 150%
I had the bright idea to Static Tune the drive and now my o speed current went from 32 Amps to 45 Amps leaving just 20 or amps before i reach my limit.
I had to change some settings on the drive to get it to become quite (during Jog the shaft would hammer)and when I started the drive the Torque accelerate the slack violently.
I am planning to reset the drive to factory default, set it into Speed mode do and autotune and then revert back to Torque control. Playing around with someone else's manipulated drive setup does not seam to work.
I am here because the customer has noted that the drive shuts off under heavy loads. The IGBT;s witll PWM from 4Khz to 2 KHz and then the current is dropped and then the drive stops due to excessive heat in the IGBT's.
I figured that telling the 65 amp drive that its a 97 Amp drive is partially to blame but I am not sure. Hence I would like a brief description of which parameters does what I have read the manual but it does not go into any other detail. Simply put I want to control the Torque on the motor nothing else nothing more.
Thank anyone who replies.
Regards
Ron:wish:
The previous engineer installed 97.5 Amps as a current limit whereas the drive has a 65 Amp limit. (Par 411 ad 412) I changed these back to the maximum motor limit which is 65 Amps. My Torque min and max is 150%
I had the bright idea to Static Tune the drive and now my o speed current went from 32 Amps to 45 Amps leaving just 20 or amps before i reach my limit.
I had to change some settings on the drive to get it to become quite (during Jog the shaft would hammer)and when I started the drive the Torque accelerate the slack violently.
I am planning to reset the drive to factory default, set it into Speed mode do and autotune and then revert back to Torque control. Playing around with someone else's manipulated drive setup does not seam to work.
I am here because the customer has noted that the drive shuts off under heavy loads. The IGBT;s witll PWM from 4Khz to 2 KHz and then the current is dropped and then the drive stops due to excessive heat in the IGBT's.
I figured that telling the 65 amp drive that its a 97 Amp drive is partially to blame but I am not sure. Hence I would like a brief description of which parameters does what I have read the manual but it does not go into any other detail. Simply put I want to control the Torque on the motor nothing else nothing more.
Thank anyone who replies.
Regards
Ron:wish: