Actual signals and parameters 199
Group 26: Motor control
This group provides controls for fine-tuning the motor control.
2507
CRIT SPEED 3 HI
0.0 … 500.0 Hz 0.1 Hz 0.0 Hz
Sets the maximum limit for critical speed range 3.
• See parameter 2503 CRIT SPEED 1 HI.
Group 26: Motor control
Code Description Range Resolution Default S
2603
IR COMP VOLT
0 … 100 V 1 V size
dependent
Sets the IR compensation voltage used for 0 Hz.
• Keep IR compensation as low as possible to prevent overheating.
• Typical IR compensation values are:
IR compensation
• When enabled, IR compensation provides an extra voltage boost to the motor at low
speeds. Use IR compensation, for example, in applications that require a high
breakaway torque.
2604
IR COMP FREQ
0 … 100% 1 80%
Sets the frequency at which IR compensation is 0 V (in % of motor frequency).
2605
U/F RATIO
1, 2 1 2
Selects the form for the U/f (voltage to frequency) ratio below field weakening point.
1 = LINEAR – Preferred for constant torque applications.
2 = SQUARED – Preferred for centrifugal pump and fan applications. (SQUARED is
more silent for most operating frequencies.)
Group 25: Critical speeds
Code Description Range Resolution Default S
A
B
A = IR compensated
B = No compensation
Typical IR compensation values:
P
N
(kW) 0.37 0.75 2.2 4.0 7.5
200…240 V units
IR comp (V) 8.4 7.7 5.6 8.4 N/A
380…480 V units
IR comp (V) 14 14 5.6 8.4 7
2603
2604
Motor
voltage
f (Hz)