UNIFREM v.3.41x
10 May 2017
Page 137 from 180
Frequency is decreased in motoric operating mode and
increased in regenerative operating mode if current treshold
is reached.
Current limit for the motor operation.
Parameter ID: 5
SETTINGS
–
> CONTROL AND REGULATION
–
> MAX. CURRENT CONTR. (MCC)
–
> Max. mot.
current M. [A]
Current limit for the regenerative operation.
Parameter ID: 549
SETTINGS
–
> CONTROL AND REGULATION
–
> MAX. CURRENT CONTR. (MCC)
–
> Max.
regen. current [A]
In specific cases, converter can adjust the restriction value according to the another criterias.
At low frequencies, the current restriction increases to the permissible overload limit in order to
achieve a higher starting torque. At high frequencies the current restriction decreases to prevent
motor operation in unstable part of the torque characteristics
(area of power derating).
Furthermore, the „Power restriction" function can reduce the current restriction, if its conditions are
met, such as
high thermal integral of converter, high cooler temperature or if the conditions of
power restriction are met when selecting parameter: PR Signal [1088]
(signal the power is
restricted according to).
The current value of the motoric restriction of the current is signalised by the diagnostic value:
Parameter ID: 494
DIAGNOSTICS
–
> Control
–
> Additional values
–
> Max. current [A]
Specific cases of maximum current limit adjustment
WARNING!
In case, that the motor is loaded constantly in regenerative mode, the MCC is active and
the STOP command is received, the situation can happen that the rotation speed will not
decrease and the drive will not be turned off. In this case, it is necessary to increase the
Fs [Hz]
F
III.
AREA
ID = 1193
I
MAX MOT.
ID = 5
Imax [A]
ID = 494
F
BOOST RMP
ID = 1191
Stiffen up
the drive
The area of
power reduction
I
nQ_60s
