Rockwell Automation 20Y PowerFlex Active Front End - Manual (Page 151)

Rockwell Automation Publication 20Y-UM001E-EN-P - July 2014 151
Appendix
C
Application Notes
Sizing Guidelines Use the following guidelines to properly size the AFE.
Basic Procedure to Size the AFE
1. Sum the DC Input current rating of the connected drives.
See the respective drive documentation specifications, or Drives in
Common Bus Configurations, publication DRIVES-AT002.
2. Multiply the total DC current by 0.9.
This compensates for the boosted DC bus voltage that is provided by the
AFE.
3. Select the AFE with the DC current rating that meets or exceeds the value
calculated in step 2.
Examples:
• Normal Duty ND, 110%, 1 minute
• Heavy Duty HD, 150%, 1 minute
Topic Page
Sizing Guidelines 151
Voltage Boost 153
Paralleling AFEs 154
DC Input Rating of Connected Drives AFE
DC
Voltage ND
Power ND
Currents ND Current
Sum x 0.9 ND Cont. DC
Output Amps AC Input
Voltage
650V 5 x 60 HP
1 x 30 HP 5 x 84.5 = 422.5 A
1 x 85.8 A 457.5A 520A 480V
DC Input Rating of Connected Drives AFE
DC
Voltage HD
Power HD
Currents HD Current
Sum x 0.9 HD Cont. DC
Output Amps AC Input
Voltage
650V 5 x 60 HP
1 x 30 HP 5 x 84.5 = 422.5 A
1 x 55.7 = 55.7A 430.4A 435A 480V