The minimum possible motor power rating allowed with any of the ATV61/ATV71 VFD is 0.25 times of VFD's nominal power rating.
For example, ATV71HD30N4 (30KW VFD) ----> The smaller motor rating allowed is 0.25 x 30KW = 7.5KW motor.
If we use the motor rating less than 7.5KW with 30KW VFD, it may not be possible to set the motor current and power rating parameters in the VFD, hence the motor protection is not guaranteed. However if the requirement is to use a smaller rating motor for testing purpose, It is possible to run the motor(for testing purpose only) by doing the below parameter settings.
a) The motor control type in motor control menu (DRC) should be set to V/F 2pt.
b) The output phase loss in Fault management menu(FLT) should be set to "Ignore"
With the above parameter settings, we can run the VFD with smaller rating motor for short time without any load for testing purpose.
For example, ATV71HD30N4 (30KW VFD) ----> The smaller motor rating allowed is 0.25 x 30KW = 7.5KW motor.
If we use the motor rating less than 7.5KW with 30KW VFD, it may not be possible to set the motor current and power rating parameters in the VFD, hence the motor protection is not guaranteed. However if the requirement is to use a smaller rating motor for testing purpose, It is possible to run the motor(for testing purpose only) by doing the below parameter settings.
a) The motor control type in motor control menu (DRC) should be set to V/F 2pt.
b) The output phase loss in Fault management menu(FLT) should be set to "Ignore"
With the above parameter settings, we can run the VFD with smaller rating motor for short time without any load for testing purpose.
Released for:Schneider Electric UK
