I work at a liquid nitrogen plant where we have 6x outdoor ariel glycol cooling fans controlled by 6x VFD's respectively.
We are using WEG 'CFW-11' VFD's to drive 25HP 480v 28.5Amp motors running at a maximum rated speed of 1770 RPM.
The issue we have, is that we constantly get slight power blips and anomolies that cause the VFDs to trip on a "DCBUS Overvoltage" fault. It's just enough to trip the VFD's, but not enough to trip any of our motor protection relays feeding our 4160v 4000HP compressor motors, or anything else out of our 480v MCC.
I was looking into installing line reactors to each of the VFD's, but upon reading through the product manual, these VFD's (despite their small size) apparently already have line reactors built into them, and they specifiy "external line reactors not required". So my question is, would an additional line reactor provide improved isolation / surge supression? Or is installing another line reactor to a drive with a built in reactor a bad idea? I am thinking that if the impedance of multiple reactors is too great, it will result in a voltage drop / reduced torque output of the motor.
Thanks in advanced!
-Shaun
We are using WEG 'CFW-11' VFD's to drive 25HP 480v 28.5Amp motors running at a maximum rated speed of 1770 RPM.
The issue we have, is that we constantly get slight power blips and anomolies that cause the VFDs to trip on a "DCBUS Overvoltage" fault. It's just enough to trip the VFD's, but not enough to trip any of our motor protection relays feeding our 4160v 4000HP compressor motors, or anything else out of our 480v MCC.
I was looking into installing line reactors to each of the VFD's, but upon reading through the product manual, these VFD's (despite their small size) apparently already have line reactors built into them, and they specifiy "external line reactors not required". So my question is, would an additional line reactor provide improved isolation / surge supression? Or is installing another line reactor to a drive with a built in reactor a bad idea? I am thinking that if the impedance of multiple reactors is too great, it will result in a voltage drop / reduced torque output of the motor.
Thanks in advanced!
-Shaun