No load amps with Powerflex 700
No load amps with Powerflex 700
(OP)
I have a 60hp AC motor controlled by a ABB Powerflex 700 Vector control drive. I notice that the no load amperage is 21A. Is this normal? ie. Is the no load amperage with drive control usually higher than using a DOL starter? If yes, why?





RE: No load amps with Powerflex 700
Also, you either have an Allen-Bradley PowerFlex 700 or an ABB drive of some model. Note that these are two different brands.
RE: No load amps with Powerflex 700
Muthu
www.edison.co.in
RE: No load amps with Powerflex 700
RE: No load amps with Powerflex 700
As DickDV points out, if the settings on your PF700 are not correct or the vector algorithm is not tuned correctly, then you could get over-excitation and hence more current at no load.
RE: No load amps with Powerflex 700
The motor nameplate is as follows:
Reliance Electric Inverter Duty Motor
Frame: 364T
Hp: 60
RPM: 2475/2680
V: 460
Amps: 68.2/67.6
Hz: 83/93
The drive parameters:
Rated kW: 45
Rated V: 480
Rated Amos:77
Motor Type: Induction
Motor NP V: 460
Motor NP FLA: 68.2
Motor NP Hertz: 83
Motor NP RPM: 1750
Motor NP Power: 60
Motor NP Pwr Units: Horsepower
Motor Cntl Sel: FVC Vector
Any other info required?
RE: No load amps with Powerflex 700
Thumbrule - No load current = 1/3rd rated current
Muthu
www.edison.co.in
RE: No load amps with Powerflex 700
RE: No load amps with Powerflex 700
RE: No load amps with Powerflex 700
RE: No load amps with Powerflex 700
The vast majority of the no-load current is magnetising current, with a small in-phase current to meet the iron, copper and windage losses. Nothing you do to the shaft will modify the magnetising current because that is inherent in the design of the motor stator and rotor.
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: No load amps with Powerflex 700