Danfoss VACON 100 FLOW Series - Page 172

Selec-
tion
num-
ber
Selection
name
Description
0
Linear
The voltage of the motor changes linearly as a function of the output frequency. The voltage changes
from the value of P3.1.4.6 (Zero Frequency Voltage) to the value of P3.1.4.3 (Voltage at Field Weakening
Point) at a frequency set in P3.1.4.2 (Field Weakening Point Frequency). Use this default setting if a dif-
ferent setting is not necessary.
1
Squared
The voltage of the motor changes from the value of P3.1.4.6 (Zero Frequency Voltage) to the value of
P3.1.4.2 (Field Weakening Point Frequency) at a squared curve. The motor operates undermagnetized
below the field weakening point and produces less torque. Use the squared U/f ratio in applications
where the torque demand is in relation to the square of the speed, for example in centrifugal fans and
pumps.
2
Program-
mable
It is possible to program the U/f curve with 3 different points: the zero frequency voltage (P1), the mid-
point voltage/ frequency (P2), and the field weakening point (P3). Use the programmable U/f curve at
low frequencies if it is necessary to have more torque. Use the identification run (P3.1.2.4) to find the
optimal settings automatically.
e30bu033
C
B
E
D
A
Un
U[V]
f[Hz]
ID603
ID602
Illustration 37: Linear and Squared Change of the Motor Voltage
A
Default: Nominal voltage of the motor
B
Field weakening point
C
Linear
D
Squared
E
Default: Nominal frequency of the motor
AB298035655957en-000201 / DPD01083172 | Danfoss A/S © 2023.08
Parameter Descriptions
VACON® 100 FLOW
Application Guide