Firmware Manual

Appendix A—Description of Parameters
PowerXL DG1 Series Adjustable Frequency Drives MN040004EN—March 2014 www.eaton.com 157
P8.4 108 V/Hz Ratio 1, 2, 3, 4 RW
Linear
0 The voltage of the motor changes linearly with the frequency in the constant flux
area from 0 Hz to the field weakening point where the nominal voltage is
supplied to the motor. A linear V/Hz ratio should be used in constant torque
applications. This default setting should be used if there is no special need
for another setting.
Squared
1 The voltage of the motor changes following a squared curve form with the
frequency in the area from 0 Hz to the field weakening point where the nominal
voltage is supplied to the motor. The motor runs under magnetized below the
field weakening point and produces less torque and electromechanical noise. A
squared V/Hz ratio can be used in applications where the torque demand of the
load is proportional to the square of the speed, e.g., in centrifugal fans and
pumps.
Figure 56. Linear and Squared Change of Motor Voltage
Programmable V/Hz curve
2 The V/Hz curve can be programmed with three different points. A programmable
V/Hz curve can be used if the other settings do not satisfy the needs of the
application.
Figure 57. Programmable V/Hz Curve
Linear with flux optimization
3 The frequency converter starts to search for the minimum motor current in order
to save energy and lower the disturbance level and the noise. This function can
be used in applications with constant motor load, such as fans, pumps, etc.
Code Modbus ID Parameter Application
RO/RW
U[V]
f [Hz]
Linear
Squared
Un
P8.5
Default: Nominal
Voltage of the Motor
Field Weakening
Point
Default: Nominal
Frequency of the
Motor
P8.7
(Default 100%)
P8.8
(Default 0%)
P8.6
(Default 5 Hz)
P8.4
U[V]
f[Hz]
Un
P8.5
Default: Nominal
Voltage of the Motor
Field Weakening
Point
Default: Nominal
Frequency of the
Motor