Technical data
89
Derating
The load capacity (current and power) decreases if the installation site altitude exceeds 1000 metres
(3281 ft), or if the ambient temperature exceeds 40 °C (104 °F).
Temperature derating
In the temperature range +40 °C (+104 °F) to +50 °C (+122 °F), the rated output current is decreased
1 % for every additional 1 °C (1.8 °F). The output current is calculated by multiplying the current given
in the rating table by the derating factor.
Example
If the ambient temperature is 50 °C (+122 °F), the derating factor is 100 % - 1 · 10 °C =
90 % or 0.90. The output current is then 0.90 · I
2N
, 0.90 · I
2hd
or 0.90 · I
cont.max
.
Altitude derating
At altitudes from 1000 to 4000 m (3281 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. If the installation site is higher than
2000 m (6562 ft) above sea level, please contact your local ABB distributor or office for further
information.
%
°C