ABB ACS800 Application Manual page 9

9
Case a)
The most common set-up, where all converters are connected to the main supply.
When the charging circuits of the converters are different, this connection is not
always allowed. Table 1 shows when the connection cannot be used.
Case b)
Converters are identical and only one converter is connected directly to the main
supply.
Case c)
Converters are not identical and only the biggest converter is connected directly to
the main supply. The AC cables to the other converters are protected by
drive-specific fuses.
Case d1)
Converters are identical and only one converter is connected directly to the main
supply. The charging circuit of the connected converter is capable of charging the
whole DC bus.
Case d2)
Converters are not identical and only the biggest converter is connected to the main
supply. Charging circuit of the connected converter is capable of charging the whole
DC bus.
Note: If the charging circuit in case d1/d2 is not capable of charging the DC bus,
connection presented in case b/c must be used.
Note: With frame sizes R5...R8 the charging circuit in case d1/d2 might not be able
to withstand the three times larger charging energies. In this case the main supply
cable is wired to all of the input rectifiers as presented in case b/c.
Note: With ACS800-11 only connection presented in case d1/d2 is allowed.
Note: With ACS800-11 220 V units, the voltage drop over the charging resistor
during charging can generate a permanent undervoltage fault. Contact your local
ABB representative for help on designing the common DC configuration!
To determine whether it is possible to leave some converters unconnected to the
main supply see Appendix A Charging circuit capacity.
Possible main supply connections