ABB ACS800 Application Manual page 27

Example 6
The DC buses of two ACS800-0120-5 (R6) and four ACS800-0260-5 (R7) are
connected together. The main supply voltage is 500 V. The total charging energy of
the DC link capacitors is
1
⋅ ( ⋅
-- -
E = 2 4700uF
tot
2
E exceeds the energy pulse withstand of the ACS800-0260-5 (R7) charging circuit.
tot
Charging resistors of two ACS800-0260-5 (R7) are able to withstand the charging
energy, E = 7335 J < E
tot
⋅ ) ⋅ (
+ 4 5700uF 1.35 500V
= 2 ⋅ 5600 J.
r
2 6 –
⋅ ) ⋅
10 = 7335J
Appendix A Charging circuit capacity
27