Emotron AB 01-3694-01r2 Functional Description 95
IxR Compensation [352]
This function compensates for the drop in voltage over dif-
ferent resistances such as (very) long motor cables, chokes
and motor stator by increasing the output voltage at a con-
stant frequency. IxR Compensation is most important at low
frequencies and is used to obtain a higher starting torque.
The maximum voltage increase is 25% of the nominal out-
put voltage. See Fig. 81.
Selecting “Automatic” will use the optimized value for the
application at that moment, between the maximum voltage
increase and the linear V/Hz curve. This selection automati-
cally corrects the IxR Compensation for different applica-
tion circumstances, such as cold start, change in viscosity,
different load on conveyor, etc. and prevents unnecessary
high values that can cause motor saturation. “User-Defined”
can be selected when the start conditions of the application
do not change and a high starting torque is always required.
A fixed IxR Compensation value can be set in the menu
[353].
Communication information
Fig. 81 IxR Comp at Linear V/Hz curve
IxR Comp_user [353]
Only visible if User-Defined is selected in previous menu.
Communication information
Flux Optimization [354]
Flux Optimization reduces the energy consumption and the
motor noise, at low or no load conditions.
Flux Optimization automatically decreases the V/Hz ratio,
depending on the actual load of the motor when the process
is in a steady situation. Fig. 82 shows the area within which
the Flux Optimization is active.
Communication information
Default: Off
Off 0 Function disabled
Automatic 1 Automatic compensation
User
Defined
2 User defined value in percent.
Modbus Instance no/DeviceNet no: 43142
Profibus slot/index 169/46
Fieldbus format UInt
Modbus format UInt
352 IxR Comp
Stp Off
A
10 20 30 40 50
Hz
f
25
%
V
100
(NG_06-F112)
IxR Comp=25%
IxR Com=0%
Default: 0.0%
Range: 0-25% x U
NOM
(0.1% of resolution)
Modbus Instance no/DeviceNet no: 43143
Profibus slot/index 169/47
Fieldbus format Long
Modbus format EInt
NOTE: A too high level of IxR Compensation could cause
motor saturation. This can cause a “Power Fault” trip.
The effect of IxR Compensation is stronger with higher
power motors.
NOTE: The motor may be overheated at low speed.
Therefore it is important that the Motor I
2
t Current [232]
is set correctly.
Default: Off
Off 0 Function disabled
On 1 Function enabled
Modbus Instance no/DeviceNet no: 43144
Profibus slot/index 169/48
Fieldbus format UInt
Modbus format UInt
353 IxR CompUsr
Stp 0.0%
A
354 Flux optim
Stp Off
A
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