ACH550-UH User’s Manual
227
Technical Data
Derating
The load capacity (current and power) decreases if the installation site altitude
exceeds 1000 meters (3300 ft), or if the ambient temperature exceeds 40 °C
(104 °F) or if 8 kHz switching frequency (parameter 2606) is used.
Temperature Derating
In the temperature range +40 °C
…
50 °C (+104 °F
…
122 °F) the rated output current
is decreased 1% for every 1 °C (1.8 °F) above +40 °C (+104 °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%/°C x 10 °C
=
90% or 0.90.
The output current is then 0.90 x I
2N
.
Altitude Derating
In altitudes from 1000
…
4000 m (3300
…
13,200 ft) above sea level, the derating is 1%
for every 100 m (330 ft). If the installation site is higher than 2000 m (6600 ft) above
sea level, please contact your local ABB distributor or office for further information.
Single Phase Supply Derating
For 208…240 Volt series drives, a single phase supply can be used. In that case, the
derating is 50%.
Switching Frequency Derating
If the 8 kHz switching frequency (parameter 2606) is used, either:
•
Derate P
N
and I
2N
to 80% or
•
Set parameter 2607
SW
FREQ
CTRL
= 1 (
ON
) which allows the drive to reduce the
switching frequency if/when the drive’s internal temperature exceeds 90 °C. See
the parameter description for 2607 for details.
