87hz Method with Powerflex 525

[Jackllx]

Hi,


I have a 2.2kw drive, this is a lift application and the manufacturer says to use the 87hz method. In theory I understand this but in practicality with a powerflex 525 i am unsure how to achieve this.


I have tried setting my motor data @ 50hz and 87hz, with my min freq at 0 and my max freq at 87hz.


I have increased the FLC of the motor and the OL current to suit it.


The drive is wired in delta and set up on a 3ph inverter with 400v.


I run the drive but it sounds really bad and then stalls.


Is there something I am missing here? Any help appreciated thanks

 

[DarrylR]

This link has some info for you

https://inverterdrive.com/file/Explanation-87Hz-to-Increase-AC-Motor-Speed-and-kW

 

[Jackllx]

This link has some info for you

https://inverterdrive.com/file/Explanation-87Hz-to-Increase-AC-Motor-Speed-and-kW

Thanks, it's moreso the config on the 525 as I have done this with Siemens drives OK previously.


Just sounds like the motor is stalling, I am allowing it to build up torque before releasing the brake etc.


Just very strange behaviour but because I haven't done this with a 525 before it could be a paramater I am missing

 

[alan_505]

Are you using the low voltage Delta motor current in the PF525?

We have quite a few PF525's with Delta wired motors running without a problem. (except when some rewired the motor in Star and left the delta current settings in the PF525)

 

[kamenges]

What values did you use for motor nameplate frequency and voltage?

Keith

 

[Jackllx]

What values did you use for motor nameplate frequency and voltage?

Keith

Hi.

Motor Nameplate:
50hz
220-230/380/400
2.2kw
FLC @ 220v Delta = 8.4a
FLC @ 400v Star = 4.85a
RPM: 1450



Motor is wired in DELTA.



P525 - 5.5k2/ 3 phase

SVC Mode
Max Voltage: 400v
Motor NP Volts: 400v
Motor NP Hertz: 87hz
Motor OL Current: 16a
Motor FLA: 8.4a
Poles: 4
RPM: 1450 - I was unsure if to increase this to match 87hz

Power: 2.2kw



I have my max freq @ 87hz too.


I can get the drive to run now but it doesn't seem like its constant torque, do any of my settings look wrong?

 

[Jackllx]

Are you using the low voltage Delta motor current in the PF525?

We have quite a few PF525's with Delta wired motors running without a problem. (except when some rewired the motor in Star and left the delta current settings in the PF525)

Yes I am, but then the OL current is to be increased by a factor of 1.732 (root 3 squared)