ABB ACS880-107

Derating
￭
Surrounding air temperature derating
In the temperature range +40…50 °C (+104…122 °F), the rated output current is derated
by 1 percentage point for every added 1 °C (1.8 °F). The output current can be calculated
by multiplying the current given in the rating table by the derating factor (k) :
T
1.00
0.90
+40 °C
+104 °F
+50 °C
+122 °F
k
0
.80
￭
Altitude derating
At altitudes more than 1000 m (3281 ft) above sea level, the output current derating
is 1 percentage point for every added 100 m (328 ft). For example, the derating factor
for 1500 m (4921 ft) is 0.95. The maximum permitted installation altitude is given in
the technical data.
If the surrounding air temperature is less than +40 °C (104 °F), the derating can be
reduced by 1.5 percentage points for every 1 °C (1.8 °F) reduction in temperature. A
few altitude derating curves are shown below.
Technical data 145