Maximum Values Table; Calculation Example - ABB ACS800 Hardware Manual

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Maximum values table

This table gives maximum allowed rms current (I
values for the du/dt filters. The filter will not overheat when these values are not
exceeded.
Du/dt filter type
FOCH0260-70
FOCH0320-50
FOCH0610-70
* In temperatures above +40 °C (+104 °F) and/or altitudes above 1000 m (3281 ft), derate the I
values as instructed on page 19.

Calculation example

An FOCH0610-70 du/dt filter has been selected for a drive which supplies three
motors with the following cables in parallel:
• 100 m MCMK 3×50+16, C = 0.6 microF/km, I
• 250 m MCMK 3×70+35, C = 0.65 microF/km, I
• 300 m MCMK 3×120+70, C = 0.8 microF/km, I
The total capacitance of the motor cables
C = 0.1 × 0.6 microF + 0.25 × 0.65 microF + 0.3 × 0.8 microF = 463 nF.
The total continuous rms current of the motors
I
The supply voltage (U
of the drive
U
The additional energy loss in the du/dt filter
E = ½ · C · (U
When 463 A and 184 mJ are compared to the values of
can be seen that a filter of type FOCH0610-70 can be used.
Filter selection
I * (A)
thmax
289
230
445
361
720
560
445
= I + I + I = 463 A.
th th1 th2 th3
) is 660 V. Thus, the average intermediate circuit DC voltage
N
= 1.35 × U = 1.35 × 660 V = 891 V.
dc N
2
) = ½ × 463 nF × (891 V)
dc
thmax
E (mJ)
max
200
280
260
340
120
180
260
th1
th2
th3
2
= 184 mJ.
) and energy dissipation (E
= 105 A.
= 148 A.
= 210 A.
Maximum values table,
)
max
thmax
it