116   Technical data
 Output derating
Derate the continuous output current of the drive if
• ambient temperature exceeds +40 °C (+104 °F) or
• drive is installed higher than 1000 m (3280 ft) above sea level
• switching frequency is other than default.
Note: The final derating factor is a multiplication of all applicable derating factors.
Ambient temperature derating
In the temperature range +40…55 °C (+104…131 °F), the rated output current is derated 
by 1% for every added 1 °C (1.8 °F) as follows. Calculate the output current by multiplying 
the current given in the rating table by the derating factor.
Altitude derating
At altitudes from 1000 to 4000 m (3300 to 13123 ft) above sea level, the derating is 1% for 
every 100 m (328 ft). For a more accurate derating, use the DriveSize PC tool.
Deratings for special settings in the drive control program
Switching frequencies other than 1.5 kHz can require output current derating. If you 
change the minimum switching frequency with parameter 97.02 Minimum switching 
frequency, calculate the derated output current by multiplying the current given in the 
rating table by the derating factor given in the table below. 
Note: Changing the value of parameter 97.01 Switching frequency reference does not 
require derating.
For more information, contact local ABB.
Frame size Derating factor (k) for the minimum switching frequencies
1kHz 2kHz 4kHz 8kHz
R10 1 0.92 0.78 0.58
R11 1 0.92 0.78 0.58
1.00
0.85
+40 °C +55 °C
+104 °F +131 °F
Derating factor
Ambient temperature