Rockwell Automation 20G PowerFlex SCR Bus Supply - Manual (Page 20)

1-6 Installation/Wiring
PowerFlex SCR Bus Supply User Manual
Publication 20S-UM001G-EN-P
Minimum Capacitance In order to commission and test the SCR Bus Supply, a minimum
capacitance is required. The design of the final installation must assure that
the minimum capacitance is connected whenever the bus supply is to be
enabled. If this minimum capacitance is not present, the bus supply internal
fault detection circuit will interpret the condition as a DC bus short and stop
pulse firing. The minimum capacitance (110 µF per SCR bus supply) may
be provided by an external capacitor bank (recommended) or a drive (as
long as the drive remains connected to the DC bus). NOTE: A capacitance
of 110 µF is typical of a 5 HP or 3.7 kW drive. To find DC bus capacitances
for specific PowerFlex drives, refer to Appendix A tables in the PowerFlex
AC Drives in Common Bus Configurations Application Guidelines
(publication DRIVES-AT002).
Maximum Loading To avoid overloading the Bus Supply, the following requirement applies:
The DC Input current sum (Normal Duty rating at 40 °C/104 °F) of the
connected drive(s) must not exceed the Bus Supply continuous DC Bus
output current rating.
For the DC Input Current values of the drives, see tables in the respective
drive documentation.
Table 1.A and Table 1.B provide guidance on the nominal operation of the
SCR Bus Supply. No overload capability is built into the tables.
Important: See “ Output Ratings ” in Appendix A for overload capability.
When an overload is being utilized in connected drives or products, that
overload current must be accounted for in the calculation to properly size
the SCR Bus Supply.
Table 1.A Normal Duty ND (110%, 1 minute; 150%, 3 seconds)
Table 1.B Heavy Duty HD (150%, 1 minute; 200%, 3 seconds)
Drive Rating Drive Output Current Drive DC Input Current SCR Bus Supply
(1)
DC
Voltage ND
Power ND Output
Currents ND Output
Current Sum ND DC Input
Currents ND DC Input
Current Sum Maximum DC
Output Amps AC Input
Voltage
540V 3 x 110 kW
1 x 45 kW 3 x 205 = 615A
1 x 85 = 85A 700A 3 x 226 = 678A
1 x 95 = 95A 773A 1000A 400V
650V 3 x 60 HP
1 x 30 HP 3 x 77 = 231A
1 x 40 = 40A 271A 3 x 84.5 = 253.5A
1 x 42.9 = 42.9A 297A 400A 480V
(1) No overload capability.
Drive Rating Drive Output Current Drive DC Input Current SCR Bus Supply (1)
DC
Voltage HD
Power HD Output
Currents HD Output
Current Sum HD DC Input
Currents HD DC Input
Current Sum Maximum DC
Output Amps AC Input
Voltage
540V 3 x 90 kW 3 x 170 = 510A 510A 3 x 192.3 = 577A 577A 600A 400V
(1) No overload capability.