Increase the Output Frequency of ABB-ACS550 Drive
Increase the Output Frequency of ABB-ACS550 Drive
(OP)
Hello Everyone!
Recently we purchased an ABB-ACS550 drive and connected it to a 5.5KW motor.When we tried to increase the output frequency above 150HZ the motor speed increases correspondingly but above 105Hz , the motor slows down and stops.
When the output frequency is then decreased the motor suddenly speeds up for a brief period and stops again.
Could anyone kindly explain as to why this happens and provide us with a solution?
Thanks so much in advance!
Recently we purchased an ABB-ACS550 drive and connected it to a 5.5KW motor.When we tried to increase the output frequency above 150HZ the motor speed increases correspondingly but above 105Hz , the motor slows down and stops.
When the output frequency is then decreased the motor suddenly speeds up for a brief period and stops again.
Could anyone kindly explain as to why this happens and provide us with a solution?
Thanks so much in advance!
RE: Increase the Output Frequency of ABB-ACS550 Drive
Safety aside a motor is designed to a specific Volts/Hertz ratio of magnetic excitation. As you overspeed the motor supplying it higher and higher Hertz without doing anything about the Volts you are driving the motor farther and farther from its designed region of operation until it becomes unstable and loses sync with the magnetic field its chasing which causes it to simply stop.
You also are reducing the motor's torque from its rated torque for every Hertz you go above the frequency listed on its plate.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Increase the Output Frequency of ABB-ACS550 Drive
RE: Increase the Output Frequency of ABB-ACS550 Drive
Carry on.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Increase the Output Frequency of ABB-ACS550 Drive
VFDs have the ability to run at higher frequencies because there are MOTORS designed to run at higher frequencies. These are often called "Spindle Motors" for high speed machine tools and you will see on the nameplate that it is designed for 400V 400Hz or something like that. THAT is when you need that feature in a VFD.
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Increase the Output Frequency of ABB-ACS550 Drive
The place where we went wrong was to assume that the motor would run at any RPM as long as the VFD allows for it (clearly that isn't the case). We understand now why the motor was behaving in this way and have taken precautions to run the motor at it's base frequency