B.2.1 Capacity

VFD sizing is based on the rated motor current and power. To achieve the rated motor power given in the table, the rated current of the VFD must be higher than or equal to the rated motor current. Also the rated power of the VFD must be higher than or equal to the rated motor power. The power ratings are the same regardless of the supply voltage within one voltage range.

Note:

1. The maximum allowed motor shaft power is limited to 1.5·PN. If the limit is exceeded, motor torque and current are automatically restricted. The function protects the input bridge of the drive against overload.

2. The ratings apply at ambient temperature of 40°C

3. It is important to check that in Common DC systems the power flowing through the common DC connection does not exceed PN.

B.2.2 Derating

The load capacity decreases if the installation site ambient temperature exceeds 40°C, the altitude exceeds 1000 meters or the switching frequency is changed from 4kHz to 8, 12 or 15kHz.

B.2.2.1 Temperature derating

The usage temperature range is-10°C–40°C. If the ambient temperature of the VFD is above 40°C, it is necessary to derate. The maximum ambient temperature is 50°C. Refer to the below list for the actual derating.

Below is the derating curve of the big-power VFDs:

B.2.2.2 Altitude derating

The device can output rated power if the installation site below 1000m. The output power decreases if the altitude exceeds 1000 meters. When the installation site altitude exceeds 1000m, derate 1% for every increase of 100m; when the installation site altitude exceeds 3000m, consult the local INVT dealer or office.

B.2.2.3 Carrier frequency derating

For Goodrive310-UL series VFDs, different power level corresponds to different carrier frequency range. The rated power of the VFD is based on the factory carrier frequency, so if it is above the factory value, the VFD needs to derate.