Efficiency; Fan Curve; Fan - Allen-Bradley PowerFlex 70 Reference Manual

Efficiency

Efficiency

Fan Curve

Fan

100
The following chart shows typical efficiency for PWM variable frequency drives,
regardless of size. Drives are most efficient at full load and full speed.
100
vs. Speed
95
vs. Load
90
85
80
75
10 20 30
When torque performance (see
between frequency and voltage is shown in the following figure. The fan/pump
curve generates voltage that is a function of the stator frequency squared up to the
motor nameplate frequency. Above base frequency voltage is a linear function of
frequency. At low speed the fan curve can be offset by the run boost parameter to
provide extra starting torque if needed. No extra parameters are needed for fan/
pump curve.
The pattern matches the speed vs. load characteristics of a centrifugal fan or
pump and optimizes the drive output to those characteristics.
Maximum Voltage
Base Voltage
(Nameplate)
Run Boost
See Fan Curve above.
Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013
40 50 60 70 80
% Speed/% Load
page 201) is set to Fan/Pump, the relationship
Base Frequency
(Nameplate)
90 100
Maximum
Frequency