Appendix A Technical Data; Derated Application; Capacity; A.1.2 Derating - Kruger Ecowatt Drive K120 Series Operation Manual

Ecowatt ® Drive K120 series
A.1 Derated application
A.1.1 Capacity
Choose a VFD model based on the rated current and power of the motor. To ensure the
rated power of the motor, the rated output current of the VFD must be greater or equal to
the rated current of the motor. The rated power of the VFD must be higher or equal to
that of the motor.
Note:
 The maximum allowable shaft power of the motor is limited to 1.5 times the rated
power of the motor. If the limit is exceeded, the VFD automatically restricts the
torque and current of the motor. This function effectively protects the input shaft
against overload.
 The rated capacity is the capacity at the ambient temperature of 40°C.
 You need to check and ensure that the power flowing through the common DC
connection in the common DC system does not exceed the rated power of the motor.
A.1.2 A.1.2 Derating
If the ambient temperature on the site where the VFD is installed exceeds 40°C, the
altitude exceeds 1000 m, or the switching frequency is changed from 4 kHz to 8, 12, or 15
kHz, the VFD needs to be derated.
A.1.2.1 Derating due to temperature
When the temperature ranges from +40°C to +50°C, the rated output current is derated
by 1% for each increased 1°C. For the actual derating, see the following figure.
Note: It is not recommended to use the VFD at a temperature higher than 50°C. If you do,
you shall be held accountable for the consequences caused.

Appendix A Technical data

Derating coefficient (%)
100
90
80
60
40
20
-10 0 10
-147-
Temperature
20 30 40 50
Technical data
T (℃)