ABB ACS480-04-09A8-1, Руководство по оборудованию

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Output derating
The load capacity ( I
N
, I
Ld
, I
Hd
) decreases in some situations. In such situations, where
full motor power is required, oversize the drive so that the total derated output current
is sufficient for the motor to reach the full power.
In an environment where more than one type of derating is necessary (for example,
high altitude and high temperature), the effects of derating are cumulative.
Note:
• I
max
is not derated.
• The motor can also have a derating on it.
• You can also use the DriveSize tool for derating.
See Surrounding air temperature derating (page 133) , Altitude derating (page 133) and
Switching frequency derating (page 134) for the derating values.
Example 1, IEC: How to calculate the derated current
The drive type is ACS480-04-018A-4, which has a nominal output current ( I
N
) of 17 A
at 400 V. Calculate the derated output current at 4 kHz switching frequency, at 1500 m
altitude and at 55 °C surrounding air temperature.
Switching frequency derating: Derating is not necessary at 4 kHz.
Altitude derating: The derating factor for 1500 m is
Surrounding air temperature derating: The derating factor for 55 °C surrounding air
temperature is
Multiply the nominal drive output current by all the applicable derating factors. In this
example, the derated output current becomes
Example 1, UL (NEC): How to calculate the derated current
The drive type is ACS480-04-014A-4, which has light-duty output current ( I
Ld
) of 14 A
at 480 V. Calculate the derated output current at 4 kHz switching frequency, at 6000 ft
altitude and at 131 °F surrounding air temperature.
Switching frequency derating: Derating is not necessary at 4 kHz.
Altitude derating: The derating factor for 6000 ft is
Surrounding air temperature derating: The derating factor for 131 °F surrounding air
temperature is
Technical data 131