Definitions; Sizing; Derating - ABB ACS355 User Manual

Definitions

Input
continuous rms input current (for dimensioning cables and fuses)
I
1N
I (480 V) continuous rms input current (for dimensioning cables and fuses) for drives
1N
with 480 V input voltage
Output
I continuous rms current. 50% overload is allowed for one minute every ten
2N
minutes.
I maximum (50% overload) current allowed for one minute every ten minutes
2,1 min/10 min
I maximum output current. Available for two seconds at start, otherwise as long
2max
as allowed by the drive temperature.
P typical motor power. The kilowatt ratings apply to most IEC 4-pole motors. The
N
horsepower ratings apply to most NEMA 4-pole motors. This is also the
maximum load through the Common DC connection and must not be
exceeded.
R0...R4 ACS355 is manufactured in frame sizes R0...R4. Some instructions and other
information that only concern certain frame sizes are marked with the symbol
of the frame size (R0...R4).

Sizing

Drive sizing is based on the rated motor current and power. To achieve the rated
motor power given in the table, the rated current of the drive must be higher than or
equal to the rated motor current. Also the rated power of the drive must be higher
than or equal to compared to the rated motor power. The power ratings are the same
regardless of the supply voltage within one voltage range.
Note 1: The maximum allowed motor shaft power is limited to 1.5 · P
exceeded, motor torque and current are automatically restricted. The function
protects the input bridge of the drive against overload.
Note 2: The ratings apply at ambient temperature of 40 °C (104 °F) for I
Note 3: It is important to check that in Common DC systems the power flowing
through the common DC connection does not exceed P

Derating

I : The load capacity decreases if the installation site ambient temperature exceeds
2N
40 °C (104 °F), the altitude exceeds 1000 meters (3300 ft) or the switching frequency
is changed from 4 kHz to 8, 12 or 16 kHz.
Temperature derating, I
In the temperature range +40 °C...+50 °C (+104 °F...+122 °F), the rated output
current (I ) is decreased by 1% for every additional 1 °C (1.8 °F). The output current
2N
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
°C
2N
Technical data 359
. If the limit is
N
2N
.
N
.
2N
.