Derating; Temperature Derating; Altitude Derating; Switching Frequency Derating - ABB ACS550 User Manual

262

Derating

The load capacity (current and power) decreases for certain situations, as defined
below. In such situations, where full motor power is required, oversize the drive so
that the derated value provides sufficient capacity.
For example, if your application requires 15.4 A of motor current and a 8 kHz
switching frequency, calculate the appropriate drive size requirement as follows:
The minimum size required = 15.4 A / 0.80 = 19.25 A
Where: 0.80 is the derating for 8 kHz switching frequency (see section
on page 262).
Referring to I
exceed the I

Temperature derating

In the temperature range +40 °C
is decreased 1% for every 1 °C (1.8 °F) above +40 °C (+104 °F). Calculate the
output current 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 × 10 °C
The output current is then 0.90 × I

Altitude derating

In altitudes 1000
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 V series drives, a single phase supply can be used. In that case, the
derating is 50%.

Switching frequency derating

When using the 8 kHz switching frequency (parameter 2606), either:
• Derate P
• Set parameter 2607
the switching frequency if/when the drive's internal temperature exceeds 90 °C.
See the parameter description for 2607 for details.
When using the 12 kHz switching frequency (parameter 2606), either:
• Derate P
ACS550-U1-032A-6 ... ACS550-U1-062A-6),
and derate ambient temperature maximum to 30 °C (86 °F),
and note that the current is limited to a maximum value of I
• Set parameter 2607
the switching frequency if/when the drive's internal temperature exceeds 80 °C.
See the parameter description for 2607 for details.
Technical data
in the ratings tables (starting from page 259), the following drives
2N
requirement of 19.25 A: ACS550-x1-023A-4, or ACS550-x1-024A-2.
2N
...
90% or 0.90.
=
4000 m (3300
... ...
/P and I /I to 80% or
N hd 2N 2hd
SWITCH FREQ CTRL
/P and I /I to 65% (to 50% for 600 V, R4 frame sizes, that is for
N hd 2N 2hd
SWITCH FREQ CTRL
50 °C (+104 °F 122 °F), the rated output current
...
or 0.90 × I .
2N 2hd
13,200 ft) above sea level, the derating is 1% for
= 1 ( ) which allows the drive to reduce
ON
= 1 ( ) which allows the drive to reduce
ON
ACS550 User's Manual
Switching frequency derating
, or
2hd