Typical motor power in light-duty use (10% overload). The kilowatt ratings apply
to most IEC 4-pole motors. The horsepower ratings apply to most NEMA 4-pole
460 V motors.
P
Ld
Maximum current with 50% overload, allowed for one minute every ten minutes
I
Hd
1) Maximum current with 30% overload, allowed for one minute every ten minutes
2) Maximum current with 25% overload, allowed for one minute every ten minutes
Typical motor power in heavy-duty use (50% overload). The kilowatt ratings apply
to most IEC 4-pole motors. The horsepower ratings apply to most NEMA 4-pole
460 V motors.
P
Hd
￭
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: ABB recommends the DriveSize dimensioning tool (available from
(http://new.abb.com/drives/software-tools/drivesize) for selecting the drive,
motor and gear combination.
￭
Deratings
The load capacity (
I
2
,
I
Ld
,
I
Hd
; note that
I
max
is not derated) 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.
Derating in case of several situations
If several situations are present at a time, the derating effect is cumulative.
Example:
If your application requires continuous 12.0 A of motor current at 8 kHz switching
frequency, the supply voltage is 400 V and the drive is situated at 1500 m, calculate
the appropriate drive size as follows:
See Switching frequency derating (page 175):
The minimum required current is 12.0 A / 0.7 = 17.2 A, where 0.7 is the derating
factor for 8 kHz switching frequency for frame R3 drives.
See Altitude derating:
The derating factor for 1500 m:
= 0.95.
The minimum current becomes then 17.2 A / 0.95 = 18.1 A.
172 Technical data
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